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Sample records for distance sampling surveys

  1. A Unimodal Model for Double Observer Distance Sampling Surveys.

    Directory of Open Access Journals (Sweden)

    Earl F Becker

    Full Text Available Distance sampling is a widely used method to estimate animal population size. Most distance sampling models utilize a monotonically decreasing detection function such as a half-normal. Recent advances in distance sampling modeling allow for the incorporation of covariates into the distance model, and the elimination of the assumption of perfect detection at some fixed distance (usually the transect line with the use of double-observer models. The assumption of full observer independence in the double-observer model is problematic, but can be addressed by using the point independence assumption which assumes there is one distance, the apex of the detection function, where the 2 observers are assumed independent. Aerially collected distance sampling data can have a unimodal shape and have been successfully modeled with a gamma detection function. Covariates in gamma detection models cause the apex of detection to shift depending upon covariate levels, making this model incompatible with the point independence assumption when using double-observer data. This paper reports a unimodal detection model based on a two-piece normal distribution that allows covariates, has only one apex, and is consistent with the point independence assumption when double-observer data are utilized. An aerial line-transect survey of black bears in Alaska illustrate how this method can be applied.

  2. Pairing call-response surveys and distance sampling for a mammalian carnivore

    Science.gov (United States)

    Hansen, Sara J. K.; Frair, Jacqueline L.; Underwood, Harold B.; Gibbs, James P.

    2015-01-01

    Density estimates accounting for differential animal detectability are difficult to acquire for wide-ranging and elusive species such as mammalian carnivores. Pairing distance sampling with call-response surveys may provide an efficient means of tracking changes in populations of coyotes (Canis latrans), a species of particular interest in the eastern United States. Blind field trials in rural New York State indicated 119-m linear error for triangulated coyote calls, and a 1.8-km distance threshold for call detectability, which was sufficient to estimate a detection function with precision using distance sampling. We conducted statewide road-based surveys with sampling locations spaced ≥6 km apart from June to August 2010. Each detected call (be it a single or group) counted as a single object, representing 1 territorial pair, because of uncertainty in the number of vocalizing animals. From 524 survey points and 75 detections, we estimated the probability of detecting a calling coyote to be 0.17 ± 0.02 SE, yielding a detection-corrected index of 0.75 pairs/10 km2 (95% CI: 0.52–1.1, 18.5% CV) for a minimum of 8,133 pairs across rural New York State. Importantly, we consider this an index rather than true estimate of abundance given the unknown probability of coyote availability for detection during our surveys. Even so, pairing distance sampling with call-response surveys provided a novel, efficient, and noninvasive means of monitoring populations of wide-ranging and elusive, albeit reliably vocal, mammalian carnivores. Our approach offers an effective new means of tracking species like coyotes, one that is readily extendable to other species and geographic extents, provided key assumptions of distance sampling are met.

  3. Using mark-recapture distance sampling methods on line transect surveys

    Science.gov (United States)

    Burt, Louise M.; Borchers, David L.; Jenkins, Kurt J.; Marques, Tigao A

    2014-01-01

    Mark–recapture distance sampling (MRDS) methods are widely used for density and abundance estimation when the conventional DS assumption of certain detection at distance zero fails, as they allow detection at distance zero to be estimated and incorporated into the overall probability of detection to better estimate density and abundance. However, incorporating MR data in DS models raises survey and analysis issues not present in conventional DS. Conversely, incorporating DS assumptions in MR models raises issues not present in conventional MR. As a result, being familiar with either conventional DS methods or conventional MR methods does not on its own put practitioners in good a position to apply MRDS methods appropriately. This study explains the sometimes subtly different varieties of MRDS survey methods and the associated concepts underlying MRDS models. This is done as far as possible without giving mathematical details – in the hope that this will make the key concepts underlying the methods accessible to a wider audience than if we were to present the concepts via equations.

  4. Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales

    KAUST Repository

    Yuan, Yuan; Bachl, Fabian E.; Lindgren, Finn; Borchers, David L.; Illian, Janine B.; Buckland, Stephen T.; Rue, Haavard; Gerrodette, Tim

    2017-01-01

    Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density can be estimated using these methods. Estimates are usually obtained at survey stratum level. For an endangered species such as the blue whale, it is desirable to estimate density and abundance at a finer spatial scale than stratum. Temporal variation in the spatial structure is also important. We formulate the process generating distance sampling data as a thinned spatial point process and propose model-based inference using a spatial log-Gaussian Cox process. The method adopts a flexible stochastic partial differential equation (SPDE) approach to model spatial structure in density that is not accounted for by explanatory variables, and integrated nested Laplace approximation (INLA) for Bayesian inference. It allows simultaneous fitting of detection and density models and permits prediction of density at an arbitrarily fine scale. We estimate blue whale density in the Eastern Tropical Pacific Ocean from thirteen shipboard surveys conducted over 22 years. We find that higher blue whale density is associated with colder sea surface temperatures in space, and although there is some positive association between density and mean annual temperature, our estimates are consistent with no trend in density across years. Our analysis also indicates that there is substantial spatially structured variation in density that is not explained by available covariates.

  5. Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales

    KAUST Repository

    Yuan, Yuan

    2017-12-28

    Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density can be estimated using these methods. Estimates are usually obtained at survey stratum level. For an endangered species such as the blue whale, it is desirable to estimate density and abundance at a finer spatial scale than stratum. Temporal variation in the spatial structure is also important. We formulate the process generating distance sampling data as a thinned spatial point process and propose model-based inference using a spatial log-Gaussian Cox process. The method adopts a flexible stochastic partial differential equation (SPDE) approach to model spatial structure in density that is not accounted for by explanatory variables, and integrated nested Laplace approximation (INLA) for Bayesian inference. It allows simultaneous fitting of detection and density models and permits prediction of density at an arbitrarily fine scale. We estimate blue whale density in the Eastern Tropical Pacific Ocean from thirteen shipboard surveys conducted over 22 years. We find that higher blue whale density is associated with colder sea surface temperatures in space, and although there is some positive association between density and mean annual temperature, our estimates are consistent with no trend in density across years. Our analysis also indicates that there is substantial spatially structured variation in density that is not explained by available covariates.

  6. Analysing designed experiments in distance sampling

    Science.gov (United States)

    Stephen T. Buckland; Robin E. Russell; Brett G. Dickson; Victoria A. Saab; Donal N. Gorman; William M. Block

    2009-01-01

    Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer's ability to detect a particular class of animals as a function of distance, distance sampling leads to density estimates...

  7. Small population size of Pribilof Rock Sandpipers confirmed through distance-sampling surveys in Alaska

    Science.gov (United States)

    Ruthrauff, Daniel R.; Tibbitts, T. Lee; Gill, Robert E.; Dementyev, Maksim N.; Handel, Colleen M.

    2012-01-01

    The Rock Sandpiper (Calidris ptilocnemis) is endemic to the Bering Sea region and unique among shorebirds in the North Pacific for wintering at high latitudes. The nominate subspecies, the Pribilof Rock Sandpiper (C. p. ptilocnemis), breeds on four isolated islands in the Bering Sea and appears to spend the winter primarily in Cook Inlet, Alaska. We used a stratified systematic sampling design and line-transect method to survey the entire breeding range of this population during springs 2001-2003. Densities were up to four times higher on the uninhabited and more northerly St. Matthew and Hall islands than on St. Paul and St. George islands, which both have small human settlements and introduced reindeer herds. Differences in density, however, appeared to be more related to differences in vegetation than to anthropogenic factors, raising some concern for prospective effects of climate change. We estimated the total population at 19 832 birds (95% CI 17 853–21 930), ranking it among the smallest of North American shorebird populations. To determine the vulnerability of C. p. ptilocnemis to anthropogenic and stochastic environmental threats, future studies should focus on determining the amount of gene flow among island subpopulations, the full extent of the subspecies' winter range, and the current trajectory of this small population.

  8. The Supernova Legacy Survey 3-year sample: Type Ia supernovae photometric distances and cosmological constraints

    Science.gov (United States)

    Guy, J.; Sullivan, M.; Conley, A.; Regnault, N.; Astier, P.; Balland, C.; Basa, S.; Carlberg, R. G.; Fouchez, D.; Hardin, D.; Hook, I. M.; Howell, D. A.; Pain, R.; Palanque-Delabrouille, N.; Perrett, K. M.; Pritchet, C. J.; Rich, J.; Ruhlmann-Kleider, V.; Balam, D.; Baumont, S.; Ellis, R. S.; Fabbro, S.; Fakhouri, H. K.; Fourmanoit, N.; González-Gaitán, S.; Graham, M. L.; Hsiao, E.; Kronborg, T.; Lidman, C.; Mourao, A. M.; Perlmutter, S.; Ripoche, P.; Suzuki, N.; Walker, E. S.

    2010-11-01

    Aims: We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshifts. Methods: Systematic uncertainties arising from light curve modeling are studied, making use of two techniques to derive the peak magnitude, shape and colour of the supernovae, and taking advantage of a precise calibration of the SNLS fields. Results: A flat ΛCDM cosmological fit to 231 SNLS high redshift type Ia supernovae alone gives Ω_M = 0.211 ± 0.034(stat) ± 0.069(sys). The dominant systematic uncertainty comes from uncertainties in the photometric calibration. Systematic uncertainties from light curve fitters come next with a total contribution of ±0.026 on Ω_M. No clear evidence is found for a possible evolution of the slope (β) of the colour-luminosity relation with redshift. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on observations obtained at the European Southern Observatory using the Very Large Telescope on the Cerro Paranal (ESO Large Programme 171.A-0486 & 176.A-0589). Based on observations (programs GS-2003B-Q-8, GN-2003B-Q-9, GS-2004A-Q-11, GN-2004A-Q-19, GS-2004B-Q-31, GN-2004B-Q-16, GS-2005A-Q-11, GN-2005A-Q-11, GS-2005B-Q-6, GN-2005B-Q-7, GN-2006A-Q-7, GN-2006B-Q-10) obtained at

  9. Distance sampling methods and applications

    CERN Document Server

    Buckland, S T; Marques, T A; Oedekoven, C S

    2015-01-01

    In this book, the authors cover the basic methods and advances within distance sampling that are most valuable to practitioners and in ecology more broadly. This is the fourth book dedicated to distance sampling. In the decade since the last book published, there have been a number of new developments. The intervening years have also shown which advances are of most use. This self-contained book covers topics from the previous publications, while also including recent developments in method, software and application. Distance sampling refers to a suite of methods, including line and point transect sampling, in which animal density or abundance is estimated from a sample of distances to detected individuals. The book illustrates these methods through case studies; data sets and computer code are supplied to readers through the book’s accompanying website.  Some of the case studies use the software Distance, while others use R code. The book is in three parts.  The first part addresses basic methods, the ...

  10. Writing for Distance Education. Samples Booklet.

    Science.gov (United States)

    International Extension Coll., Cambridge (England).

    Approaches to the format, design, and layout of printed instructional materials for distance education are illustrated in 36 samples designed to accompany the manual, "Writing for Distance Education." Each sample is presented on a single page with a note pointing out its key features. Features illustrated include use of typescript layout, a comic…

  11. An open-population hierarchical distance sampling model

    Science.gov (United States)

    Sollmann, Rachel; Beth Gardner,; Richard B Chandler,; Royle, J. Andrew; T Scott Sillett,

    2015-01-01

    Modeling population dynamics while accounting for imperfect detection is essential to monitoring programs. Distance sampling allows estimating population size while accounting for imperfect detection, but existing methods do not allow for direct estimation of demographic parameters. We develop a model that uses temporal correlation in abundance arising from underlying population dynamics to estimate demographic parameters from repeated distance sampling surveys. Using a simulation study motivated by designing a monitoring program for island scrub-jays (Aphelocoma insularis), we investigated the power of this model to detect population trends. We generated temporally autocorrelated abundance and distance sampling data over six surveys, using population rates of change of 0.95 and 0.90. We fit the data generating Markovian model and a mis-specified model with a log-linear time effect on abundance, and derived post hoc trend estimates from a model estimating abundance for each survey separately. We performed these analyses for varying number of survey points. Power to detect population changes was consistently greater under the Markov model than under the alternatives, particularly for reduced numbers of survey points. The model can readily be extended to more complex demographic processes than considered in our simulations. This novel framework can be widely adopted for wildlife population monitoring.

  12. An open-population hierarchical distance sampling model.

    Science.gov (United States)

    Sollmann, Rahel; Gardner, Beth; Chandler, Richard B; Royle, J Andrew; Sillett, T Scott

    2015-02-01

    Modeling population dynamics while accounting for imperfect detection is essential to monitoring programs. Distance sampling allows estimating population size while accounting for imperfect detection, but existing methods do not allow for estimation of demographic parameters. We develop a model that uses temporal correlation in abundance arising from underlying population dynamics to estimate demographic parameters from repeated distance sampling surveys. Using a simulation study motivated by designing a monitoring program for Island Scrub-Jays (Aphelocoma insularis), we investigated the power of this model to detect population trends. We generated temporally autocorrelated abundance and distance sampling data over six surveys, using population rates of change of 0.95 and 0.90. We fit the data generating Markovian model and a mis-specified model with a log-linear time effect on abundance, and derived post hoc trend estimates from a model estimating abundance for each survey separately. We performed these analyses for varying numbers of survey points. Power to detect population changes was consistently greater under the Markov model than under the alternatives, particularly for reduced numbers of survey points. The model can readily be extended to more complex demographic processes than considered in our simulations. This novel framework can be widely adopted for wildlife population monitoring.

  13. Steiner Distance in Graphs--A Survey

    OpenAIRE

    Mao, Yaping

    2017-01-01

    For a connected graph $G$ of order at least $2$ and $S\\subseteq V(G)$, the \\emph{Steiner distance} $d_G(S)$ among the vertices of $S$ is the minimum size among all connected subgraphs whose vertex sets contain $S$. In this paper, we summarize the known results on the Steiner distance parameters, including Steiner distance, Steiner diameter, Steiner center, Steiner median, Steiner interval, Steiner distance hereditary graph, Steiner distance stable graph, average Steiner distance, and Steiner ...

  14. Modern survey sampling

    CERN Document Server

    Chaudhuri, Arijit

    2014-01-01

    Exposure to SamplingAbstract Introduction Concepts of Population, Sample, and SamplingInitial RamificationsAbstract Introduction Sampling Design, Sampling SchemeRandom Numbers and Their Uses in Simple RandomSampling (SRS)Drawing Simple Random Samples with and withoutReplacementEstimation of Mean, Total, Ratio of Totals/Means:Variance and Variance EstimationDetermination of Sample SizesA.2 Appendix to Chapter 2 A.More on Equal Probability Sampling A.Horvitz-Thompson EstimatorA.SufficiencyA.LikelihoodA.Non-Existence Theorem More Intricacies Abstract Introduction Unequal Probability Sampling StrategiesPPS Sampling Exploring Improved WaysAbstract Introduction Stratified Sampling Cluster SamplingMulti-Stage SamplingMulti-Phase Sampling: Ratio and RegressionEstimationviiviii ContentsControlled SamplingModeling Introduction Super-Population ModelingPrediction Approach Model-Assisted Approach Bayesian Methods Spatial SmoothingSampling on Successive Occasions: Panel Rotation Non-Response and Not-at-Homes Weighting Adj...

  15. Estimating the encounter rate variance in distance sampling

    Science.gov (United States)

    Fewster, R.M.; Buckland, S.T.; Burnham, K.P.; Borchers, D.L.; Jupp, P.E.; Laake, J.L.; Thomas, L.

    2009-01-01

    The dominant source of variance in line transect sampling is usually the encounter rate variance. Systematic survey designs are often used to reduce the true variability among different realizations of the design, but estimating the variance is difficult and estimators typically approximate the variance by treating the design as a simple random sample of lines. We explore the properties of different encounter rate variance estimators under random and systematic designs. We show that a design-based variance estimator improves upon the model-based estimator of Buckland et al. (2001, Introduction to Distance Sampling. Oxford: Oxford University Press, p. 79) when transects are positioned at random. However, if populations exhibit strong spatial trends, both estimators can have substantial positive bias under systematic designs. We show that poststratification is effective in reducing this bias. ?? 2008, The International Biometric Society.

  16. The rise of survey sampling

    NARCIS (Netherlands)

    Bethlehem, J.

    2009-01-01

    This paper is about the history of survey sampling. It describes how sampling became an accepted scientific method. From the first ideas in 1895 it took some 50 years before the principles of probability sampling were widely accepted. This papers has a focus on developments in official statistics in

  17. Mahalanobis' Contributions to Sample Surveys

    Indian Academy of Sciences (India)

    Sample Survey started its operations in October 1950 under the ... and adopted random cuts for estimating the acreage under jute ... demographic factors relating to indebtedness, unemployment, ... traffic surveys, demand for currency coins and average life of .... Mahalanobis derived the optimum allocation in stratified.

  18. Study of probe-sample distance for biomedical spectra measurement

    Directory of Open Access Journals (Sweden)

    Li Lei

    2011-11-01

    Full Text Available Abstract Background Fiber-based optical spectroscopy has been widely used for biomedical applications. However, the effect of probe-sample distance on the collection efficiency has not been well investigated. Method In this paper, we presented a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for biomedical spectra measurement. This model was in general applicable to probes with single or multiple fibers at an arbitrary incident angle. In order to demonstrate the theory, a fluorescence spectrometer was used to measure the fluorescence of human finger skin at various probe-sample distances. The fluorescence spectrum and the total fluorescence intensity were recorded. Results The theoretical results show that for single fiber probes, contact measurement always provides the best results. While for multi-fiber probes, there is an optimal probe distance. When a 400- μm excitation fiber is used to deliver the light to the skin and another six 400- μm fibers surrounding the excitation fiber are used to collect the fluorescence signal, the experimental results show that human finger skin has very strong fluorescence between 475 nm and 700 nm under 450 nm excitation. The fluorescence intensity is heavily dependent on the probe-sample distance and there is an optimal probe distance. Conclusions We investigated a number of probe-sample configurations and found that contact measurement could be the primary choice for single-fiber probes, but was very inefficient for multi-fiber probes. There was an optimal probe-sample distance for multi-fiber probes. By carefully choosing the probe-sample distance, the collection efficiency could be enhanced by 5-10 times. Our experiments demonstrated that the experimental results of the probe-sample distance dependence of collection efficiency in multi-fiber probes were in general agreement with our theory.

  19. A distance limited method for sampling downed coarse woody debris

    Science.gov (United States)

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine; Michael S. Williams

    2012-01-01

    A new sampling method for down coarse woody debris is proposed based on limiting the perpendicular distance from individual pieces to a randomly chosen sample point. Two approaches are presented that allow different protocols to be used to determine field measurements; estimators for each protocol are also developed. Both protocols are compared via simulation against...

  20. A Survey of Binary Similarity and Distance Measures

    Directory of Open Access Journals (Sweden)

    Seung-Seok Choi

    2010-02-01

    Full Text Available The binary feature vector is one of the most common representations of patterns and measuring similarity and distance measures play a critical role in many problems such as clustering, classification, etc. Ever since Jaccard proposed a similarity measure to classify ecological species in 1901, numerous binary similarity and distance measures have been proposed in various fields. Applying appropriate measures results in more accurate data analysis. Notwithstanding, few comprehensive surveys on binary measures have been conducted. Hence we collected 76 binary similarity and distance measures used over the last century and reveal their correlations through the hierarchical clustering technique.

  1. Distance estimation experiment for aerial minke whale surveys

    Directory of Open Access Journals (Sweden)

    Lars Witting

    2009-09-01

    Full Text Available A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying above the cue–counting plane at 750 feet. The observer–based distance estimates were calculated from head angles estimated by angle-boards and declination angles estimated by declinometers. These distances were checked against image–based estimates of the perpendicular distance to the same whale. The 2 independent distance estimates were obtained for 21 sightings of minke whale, and there was a good agreement between the 2 types of estimates. The relative absolute deviations between the 2 estimates were on average 23% (se: 6%, with the errors in the observer–based distance estimates resembling that of a log-normal distribution. The linear regression of the observer–based estimates (obs on the image–based estimates (img was Obs=1.1Img (R2=0.85 with an intercept fixed at zero. There was no evidence of a distance estimation bias that could generate a positive bias in the absolute abundance estimated by cue–counting.

  2. INTERPRETING THE DISTANCE CORRELATION RESULTS FOR THE COMBO-17 SURVEY

    International Nuclear Information System (INIS)

    Richards, Mercedes T.; Richards, Donald St. P.; Martínez-Gómez, Elizabeth

    2014-01-01

    The accurate classification of galaxies in large-sample astrophysical databases of galaxy clusters depends sensitively on the ability to distinguish between morphological types, especially at higher redshifts. This capability can be enhanced through a new statistical measure of association and correlation, called the distance correlation coefficient, which has more statistical power to detect associations than does the classical Pearson measure of linear relationships between two variables. The distance correlation measure offers a more precise alternative to the classical measure since it is capable of detecting nonlinear relationships that may appear in astrophysical applications. We showed recently that the comparison between the distance and Pearson correlation coefficients can be used effectively to isolate potential outliers in various galaxy data sets, and this comparison has the ability to confirm the level of accuracy associated with the data. In this work, we elucidate the advantages of distance correlation when applied to large databases. We illustrate how the distance correlation measure can be used effectively as a tool to confirm nonlinear relationships between various variables in the COMBO-17 database, including the lengths of the major and minor axes, and the alternative redshift distribution. For these outlier pairs, the distance correlation coefficient is routinely higher than the Pearson coefficient since it is easier to detect nonlinear relationships with distance correlation. The V-shaped scatter plots of Pearson versus distance correlation coefficients also reveal the patterns with increasing redshift and the contributions of different galaxy types within each redshift range

  3. National Sample Survey of Registered Nurses

    Data.gov (United States)

    U.S. Department of Health & Human Services — The National Sample Survey of Registered Nurses (NSSRN) Download makes data from the survey readily available to users in a one-stop download. The Survey has been...

  4. Comparison of distance sampling estimates to a known population ...

    African Journals Online (AJOL)

    Line-transect sampling was used to obtain abundance estimates of an Ant-eating Chat Myrmecocichla formicivora population to compare these with the true size of the population. The population size was determined by a long-term banding study, and abundance estimates were obtained by surveying line transects.

  5. A comprehensive comparison of perpendicular distance sampling methods for sampling downed coarse woody debris

    Science.gov (United States)

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine; Michael S. Williams

    2013-01-01

    Many new methods for sampling down coarse woody debris have been proposed in the last dozen or so years. One of the most promising in terms of field application, perpendicular distance sampling (PDS), has several variants that have been progressively introduced in the literature. In this study, we provide an overview of the different PDS variants and comprehensive...

  6. THE GREEN BANK TELESCOPE H II REGION DISCOVERY SURVEY. III. KINEMATIC DISTANCES

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Bania, T. M. [Institute for Astrophysical Research, Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Balser, Dana S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Rood, Robert T., E-mail: Loren.Anderson@mail.wvu.edu [Astronomy Department, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903-0818 (United States)

    2012-07-20

    Using the H I emission/absorption method, we resolve the kinematic distance ambiguity and derive distances for 149 of 182 (82%) H II regions discovered by the Green Bank Telescope H II Region Discovery Survey (GBT HRDS). The HRDS is an X-band (9 GHz, 3 cm) GBT survey of 448 previously unknown H II regions in radio recombination line and radio continuum emission. Here, we focus on HRDS sources from 67 Degree-Sign {>=} l {>=} 18 Degree-Sign , where kinematic distances are more reliable. The 25 HRDS sources in this zone that have negative recombination line velocities are unambiguously beyond the orbit of the Sun, up to 20 kpc distant. They are the most distant H II regions yet discovered. We find that 61% of HRDS sources are located at the far distance, 31% at the tangent-point distance, and only 7% at the near distance. 'Bubble' H II regions are not preferentially located at the near distance (as was assumed previously) but average 10 kpc from the Sun. The HRDS nebulae, when combined with a large sample of H II regions with previously known distances, show evidence of spiral structure in two circular arc segments of mean Galactocentric radii of 4.25 and 6.0 kpc. We perform a thorough uncertainty analysis to analyze the effect of using different rotation curves, streaming motions, and a change to the solar circular rotation speed. The median distance uncertainty for our sample of H II regions is only 0.5 kpc, or 5%. This is significantly less than the median difference between the near and far kinematic distances, 6 kpc. The basic Galactic structure results are unchanged after considering these sources of uncertainty.

  7. A Bayesian Justification for Random Sampling in Sample Survey

    Directory of Open Access Journals (Sweden)

    Glen Meeden

    2012-07-01

    Full Text Available In the usual Bayesian approach to survey sampling the sampling design, plays a minimal role, at best. Although a close relationship between exchangeable prior distributions and simple random sampling has been noted; how to formally integrate simple random sampling into the Bayesian paradigm is not clear. Recently it has been argued that the sampling design can be thought of as part of a Bayesian's prior distribution. We will show here that under this scenario simple random sample can be given a Bayesian justification in survey sampling.

  8. Data Processing Procedures and Methodology for Estimating Trip Distances for the 1995 American Travel Survey (ATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, H.-L.; Rollow, J.

    2000-05-01

    The 1995 American Travel Survey (ATS) collected information from approximately 80,000 U.S. households about their long distance travel (one-way trips of 100 miles or more) during the year of 1995. It is the most comprehensive survey of where, why, and how U.S. residents travel since 1977. ATS is a joint effort by the U.S. Department of Transportation (DOT) Bureau of Transportation Statistics (BTS) and the U.S. Department of Commerce Bureau of Census (Census); BTS provided the funding and supervision of the project, and Census selected the samples, conducted interviews, and processed the data. This report documents the technical support for the ATS provided by the Center for Transportation Analysis (CTA) in Oak Ridge National Laboratory (ORNL), which included the estimation of trip distances as well as data quality editing and checking of variables required for the distance calculations.

  9. The Gould's Belt Distances Survey (GOBELINS). IV. Distance, Depth, and Kinematics of the Taurus Star-forming Region

    Science.gov (United States)

    Galli, Phillip A. B.; Loinard, Laurent; Ortiz-Léon, Gisela N.; Kounkel, Marina; Dzib, Sergio A.; Mioduszewski, Amy J.; Rodríguez, Luis F.; Hartmann, Lee; Teixeira, Ramachrisna; Torres, Rosa M.; Rivera, Juana L.; Boden, Andrew F.; Evans, Neal J., II; Briceño, Cesar; Tobin, John J.; Heyer, Mark

    2018-05-01

    We present new trigonometric parallaxes and proper motions of young stellar objects in the Taurus molecular cloud complex from observations collected with the Very Long Baseline Array as part of the Gould’s Belt Distances Survey. We detected 26 young stellar objects and derived trigonometric parallaxes for 18 stars with an accuracy of 0.3% to a few percent. We modeled the orbits of six binaries and determined the dynamical masses of the individual components in four of these systems (V1023 Tau, T Tau S, V807 Tau, and V1000 Tau). Our results are consistent with the first trigonometric parallaxes delivered by the Gaia satellite and reveal the existence of significant depth effects. We find that the central portion of the dark cloud Lynds 1495 is located at d =129.5 ± 0.3 pc, while the B216 clump in the filamentary structure connected to it is at d = 158.1 ± 1.2 pc. The closest and remotest stars in our sample are located at d = 126.6 ± 1.7 pc and d = 162.7 ± 0.8 pc, yielding a distance difference of about 36 pc. We also provide a new distance estimate for HL Tau that was recently imaged. Finally, we compute the spatial velocity of the stars with published radial velocity and investigate the kinematic properties of the various clouds and gas structures in this region.

  10. The K giant stars from the LAMOST survey data. I. Identification, metallicity, and distance

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chao; Deng, Li-Cai; Li, Jing; Gao, Shuang; Yang, Fan; Xu, Yan; Zhang, Yue-Yang; Xin, Yu; Wu, Yue [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Datun Road 20A, Beijing 100012 (China); Carlin, Jeffrey L.; Newberg, Heidi Jo [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Smith, Martin C. [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Xue, Xiang-Xiang [Max Planck Institute for Astronomy, Königstuhl 17, Heidelberg D-69117 (Germany); Jin, Ge, E-mail: liuchao@nao.cas.cn [University of Science and Technology of China, Hefei 230026 (China)

    2014-08-01

    We present a support vector machine classifier to identify the K giant stars from the LAMOST survey directly using their spectral line features. The completeness of the identification is about 75% for tests based on LAMOST stellar parameters. The contamination in the identified K giant sample is lower than 2.5%. Applying the classification method to about two million LAMOST spectra observed during the pilot survey and the first year survey, we select 298,036 K giant candidates. The metallicities of the sample are also estimated with an uncertainty of 0.13 ∼ 0.29 dex based on the equivalent widths of Mg{sub b} and iron lines. A Bayesian method is then developed to estimate the posterior probability of the distance for the K giant stars, based on the estimated metallicity and 2MASS photometry. The synthetic isochrone-based distance estimates have been calibrated using 7 globular clusters with a wide range of metallicities. The uncertainty of the estimated distance modulus at K = 11 mag, which is the median brightness of the K giant sample, is about 0.6 mag, corresponding to ∼30% in distance. As a scientific verification case, the trailing arm of the Sagittarius stream is clearly identified with the selected K giant sample. Moreover, at about 80 kpc from the Sun, we use our K giant stars to confirm a detection of stream members near the apo-center of the trailing tail. These rediscoveries of the features of the Sagittarius stream illustrate the potential of the LAMOST survey for detecting substructures in the halo of the Milky Way.

  11. Galaxy redshift surveys with sparse sampling

    International Nuclear Information System (INIS)

    Chiang, Chi-Ting; Wullstein, Philipp; Komatsu, Eiichiro; Jee, Inh; Jeong, Donghui; Blanc, Guillermo A.; Ciardullo, Robin; Gronwall, Caryl; Hagen, Alex; Schneider, Donald P.; Drory, Niv; Fabricius, Maximilian; Landriau, Martin; Finkelstein, Steven; Jogee, Shardha; Cooper, Erin Mentuch; Tuttle, Sarah; Gebhardt, Karl; Hill, Gary J.

    2013-01-01

    Survey observations of the three-dimensional locations of galaxies are a powerful approach to measure the distribution of matter in the universe, which can be used to learn about the nature of dark energy, physics of inflation, neutrino masses, etc. A competitive survey, however, requires a large volume (e.g., V survey ∼ 10Gpc 3 ) to be covered, and thus tends to be expensive. A ''sparse sampling'' method offers a more affordable solution to this problem: within a survey footprint covering a given survey volume, V survey , we observe only a fraction of the volume. The distribution of observed regions should be chosen such that their separation is smaller than the length scale corresponding to the wavenumber of interest. Then one can recover the power spectrum of galaxies with precision expected for a survey covering a volume of V survey (rather than the volume of the sum of observed regions) with the number density of galaxies given by the total number of observed galaxies divided by V survey (rather than the number density of galaxies within an observed region). We find that regularly-spaced sampling yields an unbiased power spectrum with no window function effect, and deviations from regularly-spaced sampling, which are unavoidable in realistic surveys, introduce calculable window function effects and increase the uncertainties of the recovered power spectrum. On the other hand, we show that the two-point correlation function (pair counting) is not affected by sparse sampling. While we discuss the sparse sampling method within the context of the forthcoming Hobby-Eberly Telescope Dark Energy Experiment, the method is general and can be applied to other galaxy surveys

  12. A guide to the use of distance sampling to estimate abundance of Karner blue butterflies

    Science.gov (United States)

    Grundel, Ralph

    2015-01-01

    This guide is intended to describe the use of distance sampling as a method for evaluating the abundance of Karner blue butterflies at a location. Other methods for evaluating abundance exist, including mark-release-recapture and index counts derived from Pollard-Yates surveys, for example. Although this guide is not intended to be a detailed comparison of the pros and cons of each type of method, there are important preliminary considerations to think about before selecting any method for evaluating the abundance of Karner blue butterflies.

  13. The "Tracked Roaming Transect" and distance sampling methods increase the efficiency of underwater visual censuses.

    Directory of Open Access Journals (Sweden)

    Alejo J Irigoyen

    Full Text Available Underwater visual census (UVC is the most common approach for estimating diversity, abundance and size of reef fishes in shallow and clear waters. Abundance estimation through UVC is particularly problematic in species occurring at low densities and/or highly aggregated because of their high variability at both spatial and temporal scales. The statistical power of experiments involving UVC techniques may be increased by augmenting the number of replicates or the area surveyed. In this work we present and test the efficiency of an UVC method based on diver towed GPS, the Tracked Roaming Transect (TRT, designed to maximize transect length (and thus the surveyed area with respect to diving time invested in monitoring, as compared to Conventional Strip Transects (CST. Additionally, we analyze the effect of increasing transect width and length on the precision of density estimates by comparing TRT vs. CST methods using different fixed widths of 6 and 20 m (FW3 and FW10, respectively and the Distance Sampling (DS method, in which perpendicular distance of each fish or group of fishes to the transect line is estimated by divers up to 20 m from the transect line. The TRT was 74% more time and cost efficient than the CST (all transect widths considered together and, for a given time, the use of TRT and/or increasing the transect width increased the precision of density estimates. In addition, since with the DS method distances of fishes to the transect line have to be estimated, and not measured directly as in terrestrial environments, errors in estimations of perpendicular distances can seriously affect DS density estimations. To assess the occurrence of distance estimation errors and their dependence on the observer's experience, a field experiment using wooden fish models was performed. We tested the precision and accuracy of density estimators based on fixed widths and the DS method. The accuracy of the estimates was measured comparing the actual

  14. Statistical literacy and sample survey results

    Science.gov (United States)

    McAlevey, Lynn; Sullivan, Charles

    2010-10-01

    Sample surveys are widely used in the social sciences and business. The news media almost daily quote from them, yet they are widely misused. Using students with prior managerial experience embarking on an MBA course, we show that common sample survey results are misunderstood even by those managers who have previously done a statistics course. In general, they fare no better than managers who have never studied statistics. There are implications for teaching, especially in business schools, as well as for consulting.

  15. Distance of Sample Measurement Points to Prototype Catalog Curve

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Karamehmedovic, Mirza; Perram, John

    2006-01-01

    We discuss strategies for comparing discrete data points to a catalog (reference) curve by means of the Euclidean distance from each point to the curve in a pump's head H vs. flow Qdiagram. In particular we find that a method currently in use is inaccurate. We propose several alternatives...

  16. Optimal sampling designs for large-scale fishery sample surveys in Greece

    Directory of Open Access Journals (Sweden)

    G. BAZIGOS

    2007-12-01

    The paper deals with the optimization of the following three large scale sample surveys: biological sample survey of commercial landings (BSCL, experimental fishing sample survey (EFSS, and commercial landings and effort sample survey (CLES.

  17. Drone Transport of Chemistry and Hematology Samples Over Long Distances.

    Science.gov (United States)

    Amukele, Timothy K; Hernandez, James; Snozek, Christine L H; Wyatt, Ryan G; Douglas, Matthew; Amini, Richard; Street, Jeff

    2017-11-02

    We addressed the stability of biological samples in prolonged drone flights by obtaining paired chemistry and hematology samples from 21 adult volunteers in a single phlebotomy event-84 samples total. Half of the samples were held stationary, while the other samples were flown for 3 hours (258 km) in a custom active cooling box mounted on the drone. After the flight, 19 chemistry and hematology tests were performed. Seventeen analytes had small or no bias, but glucose and potassium in flown samples showed an 8% and 6.2% bias, respectively. The flown samples (mean, 24.8°C) were a mean of 2.5°C cooler than the stationary samples (mean, 27.3°C) during transportation to the flight field as well as during the flight. The changes in glucose and potassium are consistent with the magnitude and duration of the temperature difference between the flown and stationary samples. Long drone flights of biological samples are feasible but require stringent environmental controls to ensure consistent results. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  18. 3D Distance Fields: A Survey of Techniques and Applications

    DEFF Research Database (Denmark)

    Jones, Mark; Bærentzen, Jakob Andreas; Sramek, Milos

    2006-01-01

    the distance field is signed, we may also determine if the point is internal or external to objects within the domain. The distance field has been found to be a useful construction within the areas of Computer Vision, Physics and Computer Graphics. This paper serves as a timely exposition of methods...

  19. James Brown, Sample Culture and the Permanent Distance of Glory

    Directory of Open Access Journals (Sweden)

    Steve Jones

    2009-12-01

    Full Text Available The James Brown song ‘I’m Real’ (1988 features lyrics regaled from James Brown’s back catalogue, alongside vocal samples extracted from his earlier hits. As one of the most sampled artists of the hip-hop era, James employed sampling in order to reclaim his position as the “Godfather of Soul” and express his disatisfaction at having his work overtly plundered. The central questions I pose here focus on what the choice to sample himself reveals about Brown’s status as a Soul legend, and whether the contemporaneous James could sincerely live up to the mythic status inherent to the message of ‘I’m Real’ given its self-conscious form. This confusion appears to be an extension of Walter Benjamin’s conception of déjà vu as an acoustic effect - ‘the cool tomb of long ago, from the vault of which the present seems to return only as an echo’ (Benjamin cited in Breyley, 2009: 145 - only here the slippage between past and present is quite literal, involving the discordant imbrication of two divergent temporal states. Via a detailed investigation of the song ‘I’m Real‘, I will probe Brown’s playful employment of his own past. His gambit, I will argue, may be read simultaneously as testament to his own glory, and as a signifier that the excesses of egotistic auto-projection were always more distant than they first appeared to be.

  20. Power and sample-size estimation for microbiome studies using pairwise distances and PERMANOVA

    OpenAIRE

    Kelly, Brendan J.; Gross, Robert; Bittinger, Kyle; Sherrill-Mix, Scott; Lewis, James D.; Collman, Ronald G.; Bushman, Frederic D.; Li, Hongzhe

    2015-01-01

    Motivation: The variation in community composition between microbiome samples, termed beta diversity, can be measured by pairwise distance based on either presence–absence or quantitative species abundance data. PERMANOVA, a permutation-based extension of multivariate analysis of variance to a matrix of pairwise distances, partitions within-group and between-group distances to permit assessment of the effect of an exposure or intervention (grouping factor) upon the sampled microbiome. Within-...

  1. Air sampling system for airborne surveys

    International Nuclear Information System (INIS)

    Jupiter, C.; Tipton, W.J.

    1975-01-01

    An air sampling system has been designed for installation on the Beechcraft King Air A-100 aircraft as a part of the Aerial Radiological Measuring System (ARMS). It is intended for both particle and whole gas sampling. The sampling probe is designed for isokinetic sampling and is mounted on a removable modified escape hatch cover, behind the co-pilot's seat, and extends about two feet forward of the hatch cover in the air stream lines. Directly behind the sampling probe inside the modified hatch cover is an expansion chamber, space for a 5-inch diameter filter paper cassette, and an optional four-stage cascade impactor for particle size distribution measurements. A pair of motors and blower pumps provide the necessary 0.5 atmosphere pressure across the type MSA 1106 B glass fiber filter paper to allow a flow rate of 50 cfm. The MSA 1106 B filter paper is designed to trap sub-micrometer particles with a high efficiency; it was chosen to enable a quantitative measurement of airborne radon daughters, one of the principal sources of background signals when radiological surveys are being performed. A venturi section and pressure gauges allow air flow rate measurements so that airborne contaminant concentrations may be quantified. A whole gas sampler capable of sampling a cubic meter of air is mounted inside the aircraft cabin. A nuclear counting system on board the aircraft provides capability for α, β and γ counting of filter paper samples. Design data are presented and types of survey missions which may be served by this system are described

  2. Automatic setting of the distance between sample and detector in gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    Andeweg, A.H.

    1980-01-01

    An apparatus has been developed that automatically sets the distance from the sample to the detector according to the radioactivity of the sample. The distance-setting unit works in conjuction with an automatic sample changer, and is interconnected with other components so that the counting head automatically moves to the optimum distance for the analysis of a particular sample. The distance, which is indicated digitally in increments of 0,01 mm, can be set between 18 and 995 mm at count rates that can be preset between 1000 and 10 000 counts per second. On being tested, the instrument performed well within the desired range and accuracy. Under routine conditions, the spectra were much more accurate than before, especially when samples of different radioactivity were counted

  3. Power and sample-size estimation for microbiome studies using pairwise distances and PERMANOVA.

    Science.gov (United States)

    Kelly, Brendan J; Gross, Robert; Bittinger, Kyle; Sherrill-Mix, Scott; Lewis, James D; Collman, Ronald G; Bushman, Frederic D; Li, Hongzhe

    2015-08-01

    The variation in community composition between microbiome samples, termed beta diversity, can be measured by pairwise distance based on either presence-absence or quantitative species abundance data. PERMANOVA, a permutation-based extension of multivariate analysis of variance to a matrix of pairwise distances, partitions within-group and between-group distances to permit assessment of the effect of an exposure or intervention (grouping factor) upon the sampled microbiome. Within-group distance and exposure/intervention effect size must be accurately modeled to estimate statistical power for a microbiome study that will be analyzed with pairwise distances and PERMANOVA. We present a framework for PERMANOVA power estimation tailored to marker-gene microbiome studies that will be analyzed by pairwise distances, which includes: (i) a novel method for distance matrix simulation that permits modeling of within-group pairwise distances according to pre-specified population parameters; (ii) a method to incorporate effects of different sizes within the simulated distance matrix; (iii) a simulation-based method for estimating PERMANOVA power from simulated distance matrices; and (iv) an R statistical software package that implements the above. Matrices of pairwise distances can be efficiently simulated to satisfy the triangle inequality and incorporate group-level effects, which are quantified by the adjusted coefficient of determination, omega-squared (ω2). From simulated distance matrices, available PERMANOVA power or necessary sample size can be estimated for a planned microbiome study. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. THE BOLOCAM GALACTIC PLANE SURVEY. VIII. A MID-INFRARED KINEMATIC DISTANCE DISCRIMINATION METHOD

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth-Bowers, Timothy P.; Glenn, Jason; Battersby, Cara; Ginsburg, Adam; Bally, John [CASA, University of Colorado, UCB 389, University of Colorado, Boulder, CO 80309 (United States); Rosolowsky, Erik [Department of Physics and Astronomy, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7 (Canada); Mairs, Steven [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 1A1 (Canada); Evans, Neal J. II [Department of Astronomy, University of Texas, 1 University Station C1400, Austin, TX 78712 (United States); Shirley, Yancy L., E-mail: timothy.ellsworthbowers@colorado.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2013-06-10

    We present a new distance estimation method for dust-continuum-identified molecular cloud clumps. Recent (sub-)millimeter Galactic plane surveys have cataloged tens of thousands of these objects, plausible precursors to stellar clusters, but detailed study of their physical properties requires robust distance determinations. We derive Bayesian distance probability density functions (DPDFs) for 770 objects from the Bolocam Galactic Plane Survey in the Galactic longitude range 7. Degree-Sign 5 {<=} l {<=} 65 Degree-Sign . The DPDF formalism is based on kinematic distances, and uses any number of external data sets to place prior distance probabilities to resolve the kinematic distance ambiguity (KDA) for objects in the inner Galaxy. We present here priors related to the mid-infrared absorption of dust in dense molecular regions and the distribution of molecular gas in the Galactic disk. By assuming a numerical model of Galactic mid-infrared emission and simple radiative transfer, we match the morphology of (sub-)millimeter thermal dust emission with mid-infrared absorption to compute a prior DPDF for distance discrimination. Selecting objects first from (sub-)millimeter source catalogs avoids a bias towards the darkest infrared dark clouds (IRDCs) and extends the range of heliocentric distance probed by mid-infrared extinction and includes lower-contrast sources. We derive well-constrained KDA resolutions for 618 molecular cloud clumps, with approximately 15% placed at or beyond the tangent distance. Objects with mid-infrared contrast sufficient to be cataloged as IRDCs are generally placed at the near kinematic distance. Distance comparisons with Galactic Ring Survey KDA resolutions yield a 92% agreement. A face-on view of the Milky Way using resolved distances reveals sections of the Sagittarius and Scutum-Centaurus Arms. This KDA-resolution method for large catalogs of sources through the combination of (sub-)millimeter and mid-infrared observations of molecular

  5. Reachable Distance Space: Efficient Sampling-Based Planning for Spatially Constrained Systems

    KAUST Repository

    Xinyu Tang,; Thomas, S.; Coleman, P.; Amato, N. M.

    2010-01-01

    reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the number of the robot's degrees of freedom

  6. THE GOULD’S BELT DISTANCES SURVEY (GOBELINS). II. DISTANCES AND STRUCTURE TOWARD THE ORION MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Kounkel, Marina; Hartmann, Lee [Department of Astronomy, University of Michigan, 1085 S. University Street, Ann Arbor, MI 48109 (United States); Loinard, Laurent; Ortiz-León, Gisela N.; Rodríguez, Luis F.; Pech, Gerardo; Rivera, Juana L. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de Mexico, Morelia 58089 (Mexico); Mioduszewski, Amy J. [National Radio Astronomy Observatory, Domenici Science Operations Center, 1003 Lopezville Road, Socorro, NM 87801 (United States); Dzib, Sergio A. [Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Torres, Rosa M. [Centro Universitario de Tonalá, Universidad de Guadalajara, Avenida Nuevo Perifrico No. 555, Ejido San José, Tatepozco, C.P. 48525, Tonalá, Jalisco, México (Mexico); Galli, Phillip A. B. [Université Grenoble Alpes, IPAG, F-38000, Grenoble (France); Boden, Andrew F. [Division of Physics, Math and Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Evans II, Neal J. [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Briceño, Cesar [Cerro Tololo Interamerican Observatory, Casilla 603, La Serena (Chile); Tobin, John J., E-mail: mkounkel@umich.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States)

    2017-01-10

    We present the results of the Gould’s Belt Distances Survey of young star-forming regions toward the Orion Molecular Cloud Complex. We detected 36 young stellar objects (YSOs) with the Very Large Baseline Array, 27 of which have been observed in at least three epochs over the course of two years. At least half of these YSOs belong to multiple systems. We obtained parallax and proper motions toward these stars to study the structure and kinematics of the Complex. We measured a distance of 388 ± 5 pc toward the Orion Nebula Cluster, 428 ± 10 pc toward the southern portion L1641, 388 ± 10 pc toward NGC 2068, and roughly ∼420 pc toward NGC 2024. Finally, we observed a strong degree of plasma radio scattering toward λ Ori.

  7. National Student Feedback Surveys in Distance Education: An Investigation at the UK Open University

    Science.gov (United States)

    Ashby, Alison; Richardson, John T. E.; Woodley, Alan

    2011-01-01

    National student feedback surveys are administered in a number of countries, and several of these encompass both campus-based and distance learning students. The UK Open University achieves a high ranking in the annual National Student Survey (NSS), but there are some anomalies in the results. The NSS questionnaire was administered to three…

  8. Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris

    Science.gov (United States)

    Michael S. Williams; Jeffrey H. Gove

    2003-01-01

    Coarse woody debris (CWD) plays an important role in many forest ecosystem processes. In recent years, a number of new methods have been proposed to sample CWD. These methods select individual logs into the sample using some form of unequal probability sampling. One concern with most of these methods is the difficulty in estimating the volume of each log. A new method...

  9. Automatic Samples Selection Using Histogram of Oriented Gradients (HOG Feature Distance

    Directory of Open Access Journals (Sweden)

    Inzar Salfikar

    2018-01-01

    Full Text Available Finding victims at a disaster site is the primary goal of Search-and-Rescue (SAR operations. Many technologies created from research for searching disaster victims through aerial imaging. but, most of them are difficult to detect victims at tsunami disaster sites with victims and backgrounds which are look similar. This research collects post-tsunami aerial imaging data from the internet to builds dataset and model for detecting tsunami disaster victims. Datasets are built based on distance differences from features every sample using Histogram-of-Oriented-Gradient (HOG method. We use the longest distance to collect samples from photo to generate victim and non-victim samples. We claim steps to collect samples by measuring HOG feature distance from all samples. the longest distance between samples will take as a candidate to build the dataset, then classify victim (positives and non-victim (negatives samples manually. The dataset of tsunami disaster victims was re-analyzed using cross-validation Leave-One-Out (LOO with Support-Vector-Machine (SVM method. The experimental results show the performance of two test photos with 61.70% precision, 77.60% accuracy, 74.36% recall and f-measure 67.44% to distinguish victim (positives and non-victim (negatives.

  10. Do breeding phase and detection distance influence the effective area surveyed for northern goshawks?

    Science.gov (United States)

    Roberson, A.M.; Andersen, D.E.; Kennedy, P.L.

    2005-01-01

    Broadcast surveys using conspecific calls are currently the most effective method for detecting northern goshawks (Accipiter gentilis) during the breeding season. These surveys typically use alarm calls during the nestling phase and juvenile food-begging calls during the fledgling-dependency phase. Because goshawks are most vocal during the courtship phase, we hypothesized that this phase would be an effective time to detect goshawks. Our objective was to improve current survey methodology by evaluating the probability of detecting goshawks at active nests in northern Minnesota in 3 breeding phases and at 4 broadcast distances and to determine the effective area surveyed per broadcast station. Unlike previous studies, we broadcast calls at only 1 distance per trial. This approach better quantifies (1) the relationship between distance and probability of detection, and (2) the effective area surveyed (EAS) per broadcast station. We conducted 99 broadcast trials at 14 active breeding areas. When pooled over all distances, detection rates were highest during the courtship (70%) and fledgling-dependency phases (68%). Detection rates were lowest during the nestling phase (28%), when there appeared to be higher variation in likelihood of detecting individuals. EAS per broadcast station was 39.8 ha during courtship and 24.8 ha during fledgling-dependency. Consequently, in northern Minnesota, broadcast stations may be spaced 712m and 562 m apart when conducting systematic surveys during courtship and fledgling-dependency, respectively. We could not calculate EAS for the nestling phase because probability of detection was not a simple function of distance from nest. Calculation of EAS could be applied to other areas where the probability of detection is a known function of distance.

  11. Per tree estimates with n-tree distance sampling: an application to increment core data

    Science.gov (United States)

    Thomas B. Lynch; Robert F. Wittwer

    2002-01-01

    Per tree estimates using the n trees nearest a point can be obtained by using a ratio of per unit area estimates from n-tree distance sampling. This ratio was used to estimate average age by d.b.h. classes for cottonwood trees (Populus deltoides Bartr. ex Marsh.) on the Cimarron National Grassland. Increment...

  12. The Segue K giant survey. II. A catalog of distance determinations for the Segue K giants in the galactic halo

    International Nuclear Information System (INIS)

    Xue, Xiang-Xiang; Rix, Hans-Walter; Ma, Zhibo; Morrison, Heather L.; Harding, Paul; Beers, Timothy C.; Ivans, Inese I.; Jacobson, Heather R.; Johnson, Jennifer; Lee, Young Sun; Lucatello, Sara; Rockosi, Constance M.; Sobeck, Jennifer S.; Yanny, Brian; Zhao, Gang; Allende Prieto, Carlos

    2014-01-01

    We present an online catalog of distance determinations for 6036 K giants, most of which are members of the Milky Way's stellar halo. Their medium-resolution spectra from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration are used to derive metallicities and rough gravity estimates, along with radial velocities. Distance moduli are derived from a comparison of each star's apparent magnitude with the absolute magnitude of empirically calibrated color-luminosity fiducials, at the observed (g – r) 0 color and spectroscopic [Fe/H]. We employ a probabilistic approach that makes it straightforward to properly propagate the errors in metallicities, magnitudes, and colors into distance uncertainties. We also fold in prior information about the giant-branch luminosity function and the different metallicity distributions of the SEGUE K-giant targeting sub-categories. We show that the metallicity prior plays a small role in the distance estimates, but that neglecting the luminosity prior could lead to a systematic distance modulus bias of up to 0.25 mag, compared to the case of using the luminosity prior. We find a median distance precision of 16%, with distance estimates most precise for the least metal-poor stars near the tip of the red giant branch. The precision and accuracy of our distance estimates are validated with observations of globular and open clusters. The stars in our catalog are up to 125 kpc from the Galactic center, with 283 stars beyond 50 kpc, forming the largest available spectroscopic sample of distant tracers in the Galactic halo.

  13. Validation of a Spanish Version of the Distance Education Learning Environments Survey (DELES) in Spain

    Science.gov (United States)

    Fernández-Pascual, Maria Dolores; Ferrer-Cascales, Rosario; Reig-Ferrer, Abilio; Albaladejo-Blázquez, Natalia; Walker, Scott L.

    2015-01-01

    The aim of this study was to examine the validity of the Spanish version of the Distance Education Learning Environments Survey (Sp-DELES). This instrument assesses students' perceptions of virtual learning environments using six scales: Instructor Support, Student Interaction and Collaboration, Personal Relevance, Authentic Learning, Active…

  14. Can Weighting Compensate for Sampling Issues in Internet Surveys?

    NARCIS (Netherlands)

    Vaske, J.J.; Jacobs, M.H.; Sijtsma, M.T.J.; Beaman, J.

    2011-01-01

    While Internet surveys have increased in popularity, results may not be representative of target populations. Weighting is commonly used to compensate for sampling issues. This article compared two surveys conducted in the Netherlands—a random mail survey (n = 353) and a convenience Internet survey

  15. Clustering for high-dimension, low-sample size data using distance vectors

    OpenAIRE

    Terada, Yoshikazu

    2013-01-01

    In high-dimension, low-sample size (HDLSS) data, it is not always true that closeness of two objects reflects a hidden cluster structure. We point out the important fact that it is not the closeness, but the "values" of distance that contain information of the cluster structure in high-dimensional space. Based on this fact, we propose an efficient and simple clustering approach, called distance vector clustering, for HDLSS data. Under the assumptions given in the work of Hall et al. (2005), w...

  16. Relationship between Sampling Distance and Carbon Dioxide Emission under Oil Palm Plantation

    Directory of Open Access Journals (Sweden)

    Ai Dariah

    2013-05-01

    Full Text Available A carbon dioxide emission on peatland under oil palm plantation was highly varied due to many factors involved. The objectives of the research were to evaluate the effect of sampling distance from center of oil palm tree on Carbon dioxide flux, and to study the factors that cause variability of carbon dioxide flux on peatland under oil palm plantation. The study was conducted on peatland at Arang-Arang Village, Kumpek Ulu Sub-District, Muaro Jambi District, Jambi Province, on six-years old oil palm plantation. The study was conducted in the form of observational exploratory. Emission measurements were performed on 5 selected oil palm trees at points within 100, 150, 200, 250, 300, 350, and 400 cm from the center of trunk. Carbon dioxide flux was measured using (IRGA, Li-COR 820. The results showed that there was significant correlation between the distance of sampling from center of oil palm tree and Carbon dioxide flux. The farther distance from the tree, the more decreased of Carbon dioxide flux . Before applying fertilizer, variability of soil fertility was not significantly correlated with the flux of Carbon dioxide, so the difference of Carbon dioxide flux based on distance sampling can be caused by root distribution factor. After fertilizer application, variability of Carbon dioxide flux under the oil palm tree were not only affected by differences in root distribution but also greatly influenced by fertilization.

  17. THE ARECIBO METHANOL MASER GALACTIC PLANE SURVEY. III. DISTANCES AND LUMINOSITIES

    International Nuclear Information System (INIS)

    Pandian, J. D.; Menten, K. M.; Goldsmith, P. F.

    2009-01-01

    We derive kinematic distances to the 86 6.7 GHz methanol masers discovered in the Arecibo Methanol Maser Galactic Plane Survey. The systemic velocities of the sources were derived from 13 CO (J = 2-1), CS (J = 5-4), and NH 3 observations made with the ARO Submillimeter Telescope, the APEX telescope, and the Effelsberg 100 m telescope, respectively. Kinematic distance ambiguities were resolved using H I self-absorption with H I data from the VLA Galactic Plane Survey. We observe roughly three times as many sources at the far distance compared to the near distance. The vertical distribution of the sources has a scale height of ∼ 30 pc, and is much lower than that of the Galactic thin disk. We use the distances derived in this work to determine the luminosity function of 6.7 GHz maser emission. The luminosity function has a peak at approximately 10 -6 L sun . Assuming that this luminosity function applies, the methanol maser population in the Large Magellanic Cloud and M33 is at least 4 and 14 times smaller, respectively, than in our Galaxy.

  18. Using spatiotemporal models and distance sampling to map the space use and abundance of newly metamorphosed Western Toads (Anaxyrus boreas)

    Science.gov (United States)

    Chelgren, Nathan D.; Samora, Barbara; Adams, Michael J.; McCreary, Brome

    2011-01-01

    High variability in abundance, cryptic coloration, and small body size of newly metamorphosed anurans have limited demographic studies of this life-history stage. We used line-transect distance sampling and Bayesian methods to estimate the abundance and spatial distribution of newly metamorphosed Western Toads (Anaxyrus boreas) in terrestrial habitat surrounding a montane lake in central Washington, USA. We completed 154 line-transect surveys from the commencement of metamorphosis (15 September 2009) to the date of first snow accumulation in fall (1 October 2009), and located 543 newly metamorphosed toads. After accounting for variable detection probability associated with the extent of barren habitats, estimates of total surface abundance ranged from a posterior median of 3,880 (95% credible intervals from 2,235 to 12,600) in the first week of sampling to 12,150 (5,543 to 51,670) during the second week of sampling. Numbers of newly metamorphosed toads dropped quickly with increasing distance from the lakeshore in a pattern that differed over the three weeks of the study and contradicted our original hypotheses. Though we hypothesized that the spatial distribution of toads would initially be concentrated near the lake shore and then spread outward from the lake over time, we observed the opposite. Ninety-five percent of individuals occurred within 20, 16, and 15 m of shore during weeks one, two, and three respectively, probably reflecting continued emergence of newly metamorphosed toads from the lake and mortality or burrow use of dispersed individuals. Numbers of toads were highest near the inlet stream of the lake. Distance sampling may provide a useful method for estimating the surface abundance of newly metamorphosed toads and relating their space use to landscape variables despite uncertain and variable probability of detection. We discuss means of improving the precision of estimates of total abundance.

  19. A Survey of Blue-Noise Sampling and Its Applications

    KAUST Repository

    Yan, Dongming

    2015-05-05

    In this paper, we survey recent approaches to blue-noise sampling and discuss their beneficial applications. We discuss the sampling algorithms that use points as sampling primitives and classify the sampling algorithms based on various aspects, e.g., the sampling domain and the type of algorithm. We demonstrate several well-known applications that can be improved by recent blue-noise sampling techniques, as well as some new applications such as dynamic sampling and blue-noise remeshing.

  20. A Survey of Blue-Noise Sampling and Its Applications

    KAUST Repository

    Yan, Dongming; Guo, Jian-Wei; Wang, Bin; Zhang, Xiao-Peng; Wonka, Peter

    2015-01-01

    In this paper, we survey recent approaches to blue-noise sampling and discuss their beneficial applications. We discuss the sampling algorithms that use points as sampling primitives and classify the sampling algorithms based on various aspects, e.g., the sampling domain and the type of algorithm. We demonstrate several well-known applications that can be improved by recent blue-noise sampling techniques, as well as some new applications such as dynamic sampling and blue-noise remeshing.

  1. Sample design considerations of indoor air exposure surveys

    International Nuclear Information System (INIS)

    Cox, B.G.; Mage, D.T.; Immerman, F.W.

    1988-01-01

    Concern about the potential for indoor air pollution has prompted recent surveys of radon and NO 2 concentrations in homes and personal exposure studies of volatile organics, carbon monoxide and pesticides, to name a few. The statistical problems in designing sample surveys that measure the physical environment are diverse and more complicated than those encountered in traditional surveys of human attitudes and attributes. This paper addresses issues encountered when designing indoor air quality (IAQ) studies. General statistical concepts related to target population definition, frame creation, and sample selection for area household surveys and telephone surveys are presented. The implications of different measurement approaches are discussed, and response rate considerations are described

  2. Reachable Distance Space: Efficient Sampling-Based Planning for Spatially Constrained Systems

    KAUST Repository

    Xinyu Tang,

    2010-01-25

    Motion planning for spatially constrained robots is difficult due to additional constraints placed on the robot, such as closure constraints for closed chains or requirements on end-effector placement for articulated linkages. It is usually computationally too expensive to apply sampling-based planners to these problems since it is difficult to generate valid configurations. We overcome this challenge by redefining the robot\\'s degrees of freedom and constraints into a new set of parameters, called reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the number of the robot\\'s degrees of freedom. In addition to supporting efficient sampling of configurations, we show that the RD-space formulation naturally supports planning and, in particular, we design a local planner suitable for use by sampling-based planners. We demonstrate the effectiveness and efficiency of our approach for several systems including closed chain planning with multiple loops, restricted end-effector sampling, and on-line planning for drawing/sculpting. We can sample single-loop closed chain systems with 1,000 links in time comparable to open chain sampling, and we can generate samples for 1,000-link multi-loop systems of varying topologies in less than a second. © 2010 The Author(s).

  3. Institutional Level Identity Control Strategies in the Distance Education Environment: A Survey of Administrative Staff

    Directory of Open Access Journals (Sweden)

    Alexander Amigud

    2013-12-01

    Full Text Available Physical separation of students and instructors creates the gap of anonymity and limited control over the remote learning environment. The ability of academic institutions to authenticate students and validate authorship of academic work at various points during a course is necessary for preserving not only perceived credibility but also public safety. With the growing scope of distance education programs that permeate critical areas such as healthcare, airspace, water management, and food solutions, universities have a moral obligation to employ secure measures to verify learning outcomes. This study examines the measures universities with large distance education programs employ to align identity of learners with the academic work they do, as well as the effectiveness of and challenges and barriers to their implementation. The research was undertaken using a multiple case approach and examined survey responses from five academic administrators at five officially accredited post secondary institutions in three countries. The cases examined in the study include: Athabasca University, Open University UK, Penn State University World Campus, University of Maryland University College, and eConcordia, Concordia University’s distance learning facility. This study is not an exhaustive attempt to examine all aspects of academic integrity, but rather to create awareness about various learner authentication strategies. This study confirms that secure learner authentication in the distance education environment is possible. However, with greater pressure to enhance security of learner authentication, the openness of open learning is challenged and may change as we know it.

  4. Sample design for the residential energy consumption survey

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    The purpose of this report is to provide detailed information about the multistage area-probability sample design used for the Residential Energy Consumption Survey (RECS). It is intended as a technical report, for use by statisticians, to better understand the theory and procedures followed in the creation of the RECS sample frame. For a more cursory overview of the RECS sample design, refer to the appendix entitled ``How the Survey was Conducted,`` which is included in the statistical reports produced for each RECS survey year.

  5. A Survey of Archaeological Samples Dated in 1985

    DEFF Research Database (Denmark)

    Mejdahl, Vagn

    1986-01-01

    A survey is given of archaeological samples received for dating in 1985 at the Nordic Laboratory for Thermoluminescence Dating. A total of 66 samples were dated, 42 of which were burnt stones. All results were corrected for short-term fading as measured for samples stored at room temperature...

  6. A Survey of Archaeological Samples Dated in 1984

    DEFF Research Database (Denmark)

    Mejdahl, Vagn

    A survey is given of archaeological samples dated in 1984 at the Nordic Laboratory for Thermoluminescence Dating. A total of 79 samples were dated, 49 of which were burnt stones. All results were corrected for fading as measured for samples stored for four weeks at room temperature. The alpha dose...

  7. The quality of sample surveys in a developing nation

    Directory of Open Access Journals (Sweden)

    Paul A Bourne

    2010-08-01

    Full Text Available Paul A Bourne1, Christopher AD Charles2,3, Neva South-Bourne4, Chloe Morris1, Denise Eldemire-Shearer1, Maureen D Kerr-Campbell51Department of Community Health and Psychiatry, Faculty of Medical Sciences, University of the West Indies, Mona, Kingston, Jamaica; 2King Graduate School, Monroe College, Bronx, New York, USA; 3Center for Victim Support, Harlem Hospital Center, New York, USA; 4Research assistant for Paul A Bourne; 5Systems Development Unit, Main Library, Faculty of Humanities and Education, University of the West Indies, Mona, Kingston, JamaicaBackground: In Jamaica, population census began in 1844, and many intercensal ratios obtained from the census data showed that there is a general high degree of accuracy of the data. However, statistics from the Jamaican Ministry of Health showed that there are inaccuracies in health data collected from males using sample surveys.Objectives: The objectives of the present research are to 1 investigate the accuracy of a national sample survey, 2 explore the feasibility and quality of using a subnational sample survey to represent a national survey, 3 aid other scholars in understanding the probability of using national sample surveys and subnational sample surveys, 4 assess older men’s ­evaluation of their health status, and 5 determine whether dichotomization changes self-evaluated health status.Methods: For the current study, the data used in the analysis were originally collected from 2 different sources: 1 the Jamaica Survey of Living Conditions (JSLC and 2 Survey of Older Men (SOM. Cross validation of self-evaluated data of men in Jamaica was done with comparable samples of the complete JSLC data and the SOM data, where men older than 55 years were selected from each sample.Results: In study 1, 50.2% of respondents indicated at least good self-evaluated health status compared with 74.0% in study 2. Statistical associations were found between health status and survey sample (Χ2 [df = 5

  8. Non-response weighting adjustment approach in survey sampling ...

    African Journals Online (AJOL)

    Hence the discussion is illustrated with real examples from surveys (in particular 2003 KDHS) conducted by Central Bureau of Statistics (CBS) - Kenya. Some suggestions are made for improving the quality of non-response weighting. Keywords: Survey non-response; non-response adjustment factors; weighting; sampling ...

  9. Sample Archaeological Survey of Public Use Areas, Milford Lake, Kansas

    Science.gov (United States)

    1982-09-01

    especially ceramics); Middle "" Mississippian, Middle Woodland and Central Plains archaeology ; the engineering and building technology of the Maya ...Sample Archaeological Survey of Public Use Areas -- 0C 0 awo (L" . .614 4.- -. 1?CNOV 1 40484 * , "n. O ji - 0" By Laura S. Schwiekhard Thn ’.iint haUs...RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED Milford Lake, Kansas Sample Archaeological Survey of Public Use

  10. A probabilistic sampling method (PSM for estimating geographic distance to health services when only the region of residence is known

    Directory of Open Access Journals (Sweden)

    Peek-Asa Corinne

    2011-01-01

    Full Text Available Abstract Background The need to estimate the distance from an individual to a service provider is common in public health research. However, estimated distances are often imprecise and, we suspect, biased due to a lack of specific residential location data. In many cases, to protect subject confidentiality, data sets contain only a ZIP Code or a county. Results This paper describes an algorithm, known as "the probabilistic sampling method" (PSM, which was used to create a distribution of estimated distances to a health facility for a person whose region of residence was known, but for which demographic details and centroids were known for smaller areas within the region. From this distribution, the median distance is the most likely distance to the facility. The algorithm, using Monte Carlo sampling methods, drew a probabilistic sample of all the smaller areas (Census blocks within each participant's reported region (ZIP Code, weighting these areas by the number of residents in the same age group as the participant. To test the PSM, we used data from a large cross-sectional study that screened women at a clinic for intimate partner violence (IPV. We had data on each woman's age and ZIP Code, but no precise residential address. We used the PSM to select a sample of census blocks, then calculated network distances from each census block's centroid to the closest IPV facility, resulting in a distribution of distances from these locations to the geocoded locations of known IPV services. We selected the median distance as the most likely distance traveled and computed confidence intervals that describe the shortest and longest distance within which any given percent of the distance estimates lie. We compared our results to those obtained using two other geocoding approaches. We show that one method overestimated the most likely distance and the other underestimated it. Neither of the alternative methods produced confidence intervals for the distance

  11. A probabilistic sampling method (PSM) for estimating geographic distance to health services when only the region of residence is known

    Science.gov (United States)

    2011-01-01

    Background The need to estimate the distance from an individual to a service provider is common in public health research. However, estimated distances are often imprecise and, we suspect, biased due to a lack of specific residential location data. In many cases, to protect subject confidentiality, data sets contain only a ZIP Code or a county. Results This paper describes an algorithm, known as "the probabilistic sampling method" (PSM), which was used to create a distribution of estimated distances to a health facility for a person whose region of residence was known, but for which demographic details and centroids were known for smaller areas within the region. From this distribution, the median distance is the most likely distance to the facility. The algorithm, using Monte Carlo sampling methods, drew a probabilistic sample of all the smaller areas (Census blocks) within each participant's reported region (ZIP Code), weighting these areas by the number of residents in the same age group as the participant. To test the PSM, we used data from a large cross-sectional study that screened women at a clinic for intimate partner violence (IPV). We had data on each woman's age and ZIP Code, but no precise residential address. We used the PSM to select a sample of census blocks, then calculated network distances from each census block's centroid to the closest IPV facility, resulting in a distribution of distances from these locations to the geocoded locations of known IPV services. We selected the median distance as the most likely distance traveled and computed confidence intervals that describe the shortest and longest distance within which any given percent of the distance estimates lie. We compared our results to those obtained using two other geocoding approaches. We show that one method overestimated the most likely distance and the other underestimated it. Neither of the alternative methods produced confidence intervals for the distance estimates. The algorithm

  12. Using Linked Survey Paradata to Improve Sampling Strategies in the Medical Expenditure Panel Survey

    Directory of Open Access Journals (Sweden)

    Mirel Lisa B.

    2017-06-01

    Full Text Available Using paradata from a prior survey that is linked to a new survey can help a survey organization develop more effective sampling strategies. One example of this type of linkage or subsampling is between the National Health Interview Survey (NHIS and the Medical Expenditure Panel Survey (MEPS. MEPS is a nationally representative sample of the U.S. civilian, noninstitutionalized population based on a complex multi-stage sample design. Each year a new sample is drawn as a subsample of households from the prior year’s NHIS. The main objective of this article is to examine how paradata from a prior survey can be used in developing a sampling scheme in a subsequent survey. A framework for optimal allocation of the sample in substrata formed for this purpose is presented and evaluated for the relative effectiveness of alternative substratification schemes. The framework is applied, using real MEPS data, to illustrate how utilizing paradata from the linked survey offers the possibility of making improvements to the sampling scheme for the subsequent survey. The improvements aim to reduce the data collection costs while maintaining or increasing effective responding sample sizes and response rates for a harder to reach population.

  13. Slicing, sampling, and distance-dependent effects affect network measures in simulated cortical circuit structures

    Directory of Open Access Journals (Sweden)

    Daniel Carl Miner

    2014-11-01

    Full Text Available The neuroanatomical connectivity of cortical circuits is believed to follow certain rules, the exact origins of which are still poorly understood. In particular, numerous nonrandom features, such as common neighbor clustering, overrepresentation of reciprocal connectivity, and overrepresentation of certain triadic graph motifs have been experimentally observed in cortical slice data. Some of these data, particularly regarding bidirectional connectivity are seemingly contradictory, and the reasons for this are unclear. Here we present a simple static geometric network model with distance-dependent connectivity on a realistic scale that naturally gives rise to certain elements of these observed behaviors, and may provide plausible explanations for some of the conflicting findings. Specifically, investigation of the model shows that experimentally measured nonrandom effects, especially bidirectional connectivity, may depend sensitively on experimental parameters such as slice thickness and sampling area, suggesting potential explanations for the seemingly conflicting experimental results.

  14. Slicing, sampling, and distance-dependent effects affect network measures in simulated cortical circuit structures.

    Science.gov (United States)

    Miner, Daniel C; Triesch, Jochen

    2014-01-01

    The neuroanatomical connectivity of cortical circuits is believed to follow certain rules, the exact origins of which are still poorly understood. In particular, numerous nonrandom features, such as common neighbor clustering, overrepresentation of reciprocal connectivity, and overrepresentation of certain triadic graph motifs have been experimentally observed in cortical slice data. Some of these data, particularly regarding bidirectional connectivity are seemingly contradictory, and the reasons for this are unclear. Here we present a simple static geometric network model with distance-dependent connectivity on a realistic scale that naturally gives rise to certain elements of these observed behaviors, and may provide plausible explanations for some of the conflicting findings. Specifically, investigation of the model shows that experimentally measured nonrandom effects, especially bidirectional connectivity, may depend sensitively on experimental parameters such as slice thickness and sampling area, suggesting potential explanations for the seemingly conflicting experimental results.

  15. A survey of archaeological samples dated in 1984

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1985-10-01

    A survey is given of archaeological samples dated in 1984 at the Nordic Laboratory for Thermoluminescence Dating. A total of 79 samples were dated, 49 of which were burnt stones. All results were corrected for fading as measured for samples stored for four weeks at room temperature. The alpha dose contribution from uranium in the quartz and feldspar grains was included assuming an alpha efficiency facotr of 0.1 for quartz and 0.2 for feldspars. (author)

  16. Northern Marshall Islands radiological survey: sampling and analysis summary

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.; Conrado, C.L.; Eagle, R.J.; Stuart, M.L.

    1981-07-23

    A radiological survey was conducted in the Northern Marshall Islands to document reamining external gamma exposures from nuclear tests conducted at Enewetak and Bikini Atolls. An additional program was later included to obtain terrestrial and marine samples for radiological dose assessment for current or potential atoll inhabitants. This report is the first of a series summarizing the results from the terrestrial and marine surveys. The sample collection and processing procedures and the general survey methodology are discussed; a summary of the collected samples and radionuclide analyses is presented. Over 5400 samples were collected from the 12 atolls and 2 islands and prepared for analysis including 3093 soil, 961 vegetation, 153 animal, 965 fish composite samples (average of 30 fish per sample), 101 clam, 50 lagoon water, 15 cistern water, 17 groundwater, and 85 lagoon sediment samples. A complete breakdown by sample type, atoll, and island is given here. The total number of analyses by radionuclide are 8840 for /sup 241/Am, 6569 for /sup 137/Cs, 4535 for /sup 239 +240/Pu, 4431 for /sup 90/Sr, 1146 for /sup 238/Pu, 269 for /sup 241/Pu, and 114 each for /sup 239/Pu and /sup 240/Pu. A complete breakdown by sample category, atoll or island, and radionuclide is also included.

  17. Northern Marshall Islands radiological survey: sampling and analysis summary

    International Nuclear Information System (INIS)

    Robison, W.L.; Conrado, C.L.; Eagle, R.J.; Stuart, M.L.

    1981-01-01

    A radiological survey was conducted in the Northern Marshall Islands to document reamining external gamma exposures from nuclear tests conducted at Enewetak and Bikini Atolls. An additional program was later included to obtain terrestrial and marine samples for radiological dose assessment for current or potential atoll inhabitants. This report is the first of a series summarizing the results from the terrestrial and marine surveys. The sample collection and processing procedures and the general survey methodology are discussed; a summary of the collected samples and radionuclide analyses is presented. Over 5400 samples were collected from the 12 atolls and 2 islands and prepared for analysis including 3093 soil, 961 vegetation, 153 animal, 965 fish composite samples (average of 30 fish per sample), 101 clam, 50 lagoon water, 15 cistern water, 17 groundwater, and 85 lagoon sediment samples. A complete breakdown by sample type, atoll, and island is given here. The total number of analyses by radionuclide are 8840 for 241 Am, 6569 for 137 Cs, 4535 for 239+240 Pu, 4431 for 90 Sr, 1146 for 238 Pu, 269 for 241 Pu, and 114 each for 239 Pu and 240 Pu. A complete breakdown by sample category, atoll or island, and radionuclide is also included

  18. Latin America and the Caribbean: A Survey of Distance Education 1991. New Papers on Higher Education: Studies and Research 5.

    Science.gov (United States)

    Carty, Joan

    Country profiles compiled through a survey of distance education in Latin America and the Caribbean form the contents of this document. Seventeen countries were surveyed in Latin America: Argentina; Bolivia; Brazil; Chile; Colombia; Costa Rica; Ecuador; French Guiana; Guatemala; Guyana; Honduras; Mexico; Nicaragua; Panama; Peru; Uruguay; and…

  19. Type Ia Supernova Properties as a Function of the Distance to the Host Galaxy in the SDSS-II SN Survey

    Energy Technology Data Exchange (ETDEWEB)

    Galbany, Lluis [Institut de Fisica d' Altes Energies (IFAE), Barcelona (Spain); et al.

    2012-08-20

    We use type-Ia supernovae (SNe Ia) discovered by the SDSS-II SN Survey to search for dependencies between SN Ia properties and the projected distance to the host galaxy center, using the distance as a proxy for local galaxy properties (local star-formation rate, local metallicity, etc.). The sample consists of almost 200 spectroscopically or photometrically confirmed SNe Ia at redshifts below 0.25. The sample is split into two groups depending on the morphology of the host galaxy. We fit light-curves using both MLCS2k2 and SALT2, and determine color (AV, c) and light-curve shape (delta, x1) parameters for each SN Ia, as well as its residual in the Hubble diagram. We then correlate these parameters with both the physical and the normalized distances to the center of the host galaxy and look for trends in the mean values and scatters of these parameters with increasing distance. The most significant (at the 4-sigma level) finding is that the average fitted AV from MLCS2k2 and c from SALT2 decrease with the projected distance for SNe Ia in spiral galaxies. We also find indications that SNe in elliptical galaxies tend to have narrower light-curves if they explode at larger distances, although this may be due to selection effects in our sample. We do not find strong correlations between the residuals of the distance moduli with respect to the Hubble flow and the galactocentric distances, which indicates a limited correlation between SN magnitudes after standardization and local host metallicity.

  20. Research Note Pilot survey to assess sample size for herbaceous ...

    African Journals Online (AJOL)

    A pilot survey to determine sub-sample size (number of point observations per plot) for herbaceous species composition assessments, using a wheel-point apparatus applying the nearest-plant method, was conducted. Three plots differing in species composition on the Zululand coastal plain were selected, and on each plot ...

  1. The Next Generation Virgo Cluster Survey (NGVS). XVIII. Measurement and Calibration of Surface Brightness Fluctuation Distances for Bright Galaxies in Virgo (and Beyond)

    Science.gov (United States)

    Cantiello, Michele; Blakeslee, John P.; Ferrarese, Laura; Côté, Patrick; Roediger, Joel C.; Raimondo, Gabriella; Peng, Eric W.; Gwyn, Stephen; Durrell, Patrick R.; Cuillandre, Jean-Charles

    2018-04-01

    We describe a program to measure surface brightness fluctuation (SBF) distances to galaxies observed in the Next Generation Virgo Cluster Survey (NGVS), a photometric imaging survey covering 104 deg2 of the Virgo cluster in the u*, g, i, and z bandpasses with the Canada–France–Hawaii Telescope. We describe the selection of the sample galaxies, the procedures for measuring the apparent i-band SBF magnitude {\\overline{m}}i, and the calibration of the absolute Mibar as a function of observed stellar population properties. The multiband NGVS data set provides multiple options for calibrating the SBF distances, and we explore various calibrations involving individual color indices as well as combinations of two different colors. Within the color range of the present sample, the two-color calibrations do not significantly improve the scatter with respect to wide-baseline, single-color calibrations involving u*. We adopt the ({u}* -z) calibration as a reference for the present galaxy sample, with an observed scatter of 0.11 mag. For a few cases that lack good u* photometry, we use an alternative relation based on a combination of (g-i) and (g-z) colors, with only a slightly larger observed scatter of 0.12 mag. The agreement of our measurements with the best existing distance estimates provides confidence that our measurements are accurate. We present a preliminary catalog of distances for 89 galaxies brighter than B T ≈ 13.0 mag within the survey footprint, including members of the background M and W Clouds at roughly twice the distance of the main body of the Virgo cluster. The extension of the present work to fainter and bluer galaxies is in progress.

  2. A survey of archaeological samples dated in 1988

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1989-08-01

    A survey is given of archaeological samples dated in 1988 at the Nordic Laboratory for Thermoluminescence Dating. A total of 67 samples were dated. The results were corrected for short-term fading of feldspars as measured for samples stored at room temperature for four weeks or at 100 deg. C for two weeks. The beta dose from potassium and rubidium in feldspar, and the alpha dose from uranium and thorium in quartz and feldspar were included assuming alpha efficiency factors of 0.1 for quartz and 0.2 for feldspar. (author) 22 tabs., 1 ill., 14 refs

  3. A survey of archaeological samples dated in 1987

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1988-10-01

    A survey is given of archaeological samples dated in 1987 at the Nordic Laboratory for Thermoluminescence Dating. A total of 74 samples were dated. The results were corrected for short-term fading of feldspars as measured for samples stored at room temperature for four weeks or at 100 deg. C for two weeks. The beta dose from potassium and rubidium in feldspar, and the alpha dose from uranium and thorium in quartz and feldspar were included, assuming alpha efficiency factors of 0.1 for quartz and 0.2 for feldspar. (author) 20 tabs., 29 refs

  4. A survey of archaeological samples dated in 1985

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1986-11-01

    A survey is given of archaeological samples received for dating in 1985 at the Nordic Laboratory for Thermoluminescence Dating. A total of 66 samples were dated, 42 of which were burnt stones. All results were corrected for short- term fading as measured for samples stored at room temperature for four weeks. The beta dose from potassium and rubidium in feldspar and the alpha dose from uranium and thorium in quarts and feldspar were included assuming alpha efficiency factors of 0.1 for quartz and 0.2 for feldspar. (author)

  5. A survey of archaeological samples dated in 1986

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1987-10-01

    A survey is given of archaeological samples dated in 1986 at the Nordic Laboratory for Thermoluminescence Dating. A total of 56 samples were dated. The results were corrected for shortterm fading measured for samples stored for four weeks at room temperature or at 100 deg. C. The beta dose from potassium and rubidium in feldspar and the alpha dose from uranium and thorium in quartz and feldspar grain were included assuming alpha efficiency factors of 0.1 and 0.2 for quartz and feldspar, respectively. 21 refs. (author)

  6. Probability sampling design in ethnobotanical surveys of medicinal plants

    Directory of Open Access Journals (Sweden)

    Mariano Martinez Espinosa

    2012-07-01

    Full Text Available Non-probability sampling design can be used in ethnobotanical surveys of medicinal plants. However, this method does not allow statistical inferences to be made from the data generated. The aim of this paper is to present a probability sampling design that is applicable in ethnobotanical studies of medicinal plants. The sampling design employed in the research titled "Ethnobotanical knowledge of medicinal plants used by traditional communities of Nossa Senhora Aparecida do Chumbo district (NSACD, Poconé, Mato Grosso, Brazil" was used as a case study. Probability sampling methods (simple random and stratified sampling were used in this study. In order to determine the sample size, the following data were considered: population size (N of 1179 families; confidence coefficient, 95%; sample error (d, 0.05; and a proportion (p, 0.5. The application of this sampling method resulted in a sample size (n of at least 290 families in the district. The present study concludes that probability sampling methods necessarily have to be employed in ethnobotanical studies of medicinal plants, particularly where statistical inferences have to be made using data obtained. This can be achieved by applying different existing probability sampling methods, or better still, a combination of such methods.

  7. A NEW CEPHEID DISTANCE TO THE GIANT SPIRAL M101 BASED ON IMAGE SUBTRACTION OF HUBBLE SPACE TELESCOPE/ADVANCED CAMERA FOR SURVEYS OBSERVATIONS

    International Nuclear Information System (INIS)

    Shappee, Benjamin J.; Stanek, K. Z.

    2011-01-01

    We accurately determine a new Cepheid distance to M101 (NGC 5457) using archival Hubble Space Telescope (HST)/Advanced Camera for Surveys V and I time series photometry of two fields within the galaxy. We make a slight modification to the ISIS image subtraction package to obtain optimal differential light curves from HST data. We discovered 827 Cepheids with periods between 3 and 80 days, the largest extragalactic sample of Cepheids observed with HST by a factor of two. With this large Cepheid sample, we find that the relative distance of M101 from the Large Magellanic Cloud is Δμ LMC = 10.63 ± 0.04 (random) ± 0.06 (systematic) mag. If we use the geometrically determined maser distance to NGC 4258 as our distance anchor, the distance modulus of M101 is μ 0 = 29.04 ± 0.05 (random) ± 0.18 (systematic) mag or D = 6.4 ± 0.2 (random) ± 0.5 (systematic) Mpc. The uncertainty is dominated by the maser distance estimate (±0.15 mag), which should improve over the next few years. We determine a steep metallicity dependence, γ, for our Cepheid sample through two methods, yielding γ = -0.80 ± 0.21 (random) ± 0.06 (systematic) mag dex -1 and γ = -0.72 +0.22 -0.25 (random) ± 0.06 (systematic) mag dex -1 . We see marginal evidence for variations in the Wesenheit period-luminosity relation slope as a function of deprojected galactocentric radius. We also use the tip of the red giant branch method to independently determine the distance modulus to M101 of μ 0 = 29.05 ± 0.06 (random) ± 0.12 (systematic) mag.

  8. Emigration Rates From Sample Surveys: An Application to Senegal.

    Science.gov (United States)

    Willekens, Frans; Zinn, Sabine; Leuchter, Matthias

    2017-12-01

    What is the emigration rate of a country, and how reliable is that figure? Answering these questions is not at all straightforward. Most data on international migration are census data on foreign-born population. These migrant stock data describe the immigrant population in destination countries but offer limited information on the rate at which people leave their country of origin. The emigration rate depends on the number leaving in a given period and the population at risk of leaving, weighted by the duration at risk. Emigration surveys provide a useful data source for estimating emigration rates, provided that the estimation method accounts for sample design. In this study, emigration rates and confidence intervals are estimated from a sample survey of households in the Dakar region in Senegal, which was part of the Migration between Africa and Europe survey. The sample was a stratified two-stage sample with oversampling of households with members abroad or return migrants. A combination of methods of survival analysis (time-to-event data) and replication variance estimation (bootstrapping) yields emigration rates and design-consistent confidence intervals that are representative for the study population.

  9. Distance to green space and physical activity: a danish national representative survey

    DEFF Research Database (Denmark)

    Toftager, Mette; Ekholm, Ola; Schipperijn, Jasper

    2011-01-01

    This study examines the relationship between distance to green space and the level of physical activity among the population of Denmark. In addition, the relationship between distance to green space and obesity is investigated.......This study examines the relationship between distance to green space and the level of physical activity among the population of Denmark. In addition, the relationship between distance to green space and obesity is investigated....

  10. Evaluation of the role of location and distance in recruitment in respondent-driven sampling

    Directory of Open Access Journals (Sweden)

    Hayes Richard J

    2011-10-01

    Full Text Available Abstract Background Respondent-driven sampling(RDS is an increasingly widely used variant of a link tracing design for recruiting hidden populations. The role of the spatial distribution of the target population has not been robustly examined for RDS. We examine patterns of recruitment by location, and how they may have biased an RDS study findings. Methods Total-population data were available on a range of characteristics on a population of 2402 male household-heads from an open cohort of 25 villages in rural Uganda. The locations of households were known a-priori. An RDS survey was carried out in this population, employing current RDS methods of sampling and statistical inference. Results There was little heterogeneity in the population by location. Data suggested more distant contacts were less likely to be reported, and therefore recruited, but if reported more distant contacts were as likely as closer contacts to be recruited. There was no evidence that closer proximity to a village meeting place was associated with probability of being recruited, however it was associated with a higher probability of recruiting a larger number of recruits. People living closer to an interview site were more likely to be recruited. Conclusions Household location affected the overall probability of recruitment, and the probability of recruitment by a specific recruiter. Patterns of recruitment do not appear to have greatly biased estimates in this study. The observed patterns could result in bias in more geographically heterogeneous populations. Care is required in RDS studies when choosing the network size question and interview site location(s.

  11. Sample size reduction in groundwater surveys via sparse data assimilation

    KAUST Repository

    Hussain, Z.

    2013-04-01

    In this paper, we focus on sparse signal recovery methods for data assimilation in groundwater models. The objective of this work is to exploit the commonly understood spatial sparsity in hydrodynamic models and thereby reduce the number of measurements to image a dynamic groundwater profile. To achieve this we employ a Bayesian compressive sensing framework that lets us adaptively select the next measurement to reduce the estimation error. An extension to the Bayesian compressive sensing framework is also proposed which incorporates the additional model information to estimate system states from even lesser measurements. Instead of using cumulative imaging-like measurements, such as those used in standard compressive sensing, we use sparse binary matrices. This choice of measurements can be interpreted as randomly sampling only a small subset of dug wells at each time step, instead of sampling the entire grid. Therefore, this framework offers groundwater surveyors a significant reduction in surveying effort without compromising the quality of the survey. © 2013 IEEE.

  12. Sample size reduction in groundwater surveys via sparse data assimilation

    KAUST Repository

    Hussain, Z.; Muhammad, A.

    2013-01-01

    In this paper, we focus on sparse signal recovery methods for data assimilation in groundwater models. The objective of this work is to exploit the commonly understood spatial sparsity in hydrodynamic models and thereby reduce the number of measurements to image a dynamic groundwater profile. To achieve this we employ a Bayesian compressive sensing framework that lets us adaptively select the next measurement to reduce the estimation error. An extension to the Bayesian compressive sensing framework is also proposed which incorporates the additional model information to estimate system states from even lesser measurements. Instead of using cumulative imaging-like measurements, such as those used in standard compressive sensing, we use sparse binary matrices. This choice of measurements can be interpreted as randomly sampling only a small subset of dug wells at each time step, instead of sampling the entire grid. Therefore, this framework offers groundwater surveyors a significant reduction in surveying effort without compromising the quality of the survey. © 2013 IEEE.

  13. Testing modified gravity at large distances with the HI Nearby Galaxy Survey's rotation curves

    Science.gov (United States)

    Mastache, Jorge; Cervantes-Cota, Jorge L.; de la Macorra, Axel

    2013-03-01

    Recently a new—quantum motivated—theory of gravity has been proposed that modifies the standard Newtonian potential at large distances when spherical symmetry is considered. Accordingly, Newtonian gravity is altered by adding an extra Rindler acceleration term that has to be phenomenologically determined. Here we consider a standard and a power-law generalization of the Rindler modified Newtonian potential. The new terms in the gravitational potential are hypothesized to play the role of dark matter in galaxies. Our galactic model includes the mass of the integrated gas, and stars for which we consider three stellar mass functions (Kroupa, diet-Salpeter, and free mass model). We test this idea by fitting rotation curves of seventeen low surface brightness galaxies from the HI Nearby Galaxy Survey (THINGS). We find that the Rindler parameters do not perform a suitable fit to the rotation curves in comparison to standard dark matter profiles (Navarro-Frenk-White and Burkert) and, in addition, the computed parameters of the Rindler gravity show a high spread, posing the model as a nonacceptable alternative to dark matter.

  14. Distances in zero-divisor and total graphs from commutative rings–A survey

    Directory of Open Access Journals (Sweden)

    T. Tamizh Chelvam

    2016-12-01

    Full Text Available There are so many ways to construct graphs from algebraic structures. Most popular constructions are Cayley graphs, commuting graphs and non-commuting graphs from finite groups and zero-divisor graphs and total graphs from commutative rings. For a commutative ring R with non-zero identity, we denote the set of zero-divisors and unit elements of R by Z(R and U(R, respectively. One of the associated graphs to a ring R is the zero-divisor graph; it is a simple graph with vertex set Z(R∖{0}, and two vertices x and y are adjacent if and only if xy=0. This graph was first introduced by Beck, where all the elements of R are considered as the vertices. Anderson and Badawi, introduced the total graph of R, as the simple graph with all elements of R as vertices, and two distinct vertices x and y are adjacent if and only if x+y∈Z(R. For a given graph G, the concept of connectedness, diameter and girth are always of great interest. Several authors extensively studied about the zero-divisor and total graphs from commutative rings. In this paper, we present a survey of results obtained with regard to distances in zero-divisor and total graphs.

  15. Choosing a Cluster Sampling Design for Lot Quality Assurance Sampling Surveys

    OpenAIRE

    Hund, Lauren; Bedrick, Edward J.; Pagano, Marcello

    2015-01-01

    Lot quality assurance sampling (LQAS) surveys are commonly used for monitoring and evaluation in resource-limited settings. Recently several methods have been proposed to combine LQAS with cluster sampling for more timely and cost-effective data collection. For some of these methods, the standard binomial model can be used for constructing decision rules as the clustering can be ignored. For other designs, considered here, clustering is accommodated in the design phase. In this paper, we comp...

  16. DISTANCES TO DARK CLOUDS: COMPARING EXTINCTION DISTANCES TO MASER PARALLAX DISTANCES

    International Nuclear Information System (INIS)

    Foster, Jonathan B.; Jackson, James M.; Stead, Joseph J.; Hoare, Melvin G.; Benjamin, Robert A.

    2012-01-01

    We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near-infrared (Two Micron All Sky Survey and UKIRT Infrared Deep Sky Survey) surveys. Very long baseline interferometry parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validation gives us confidence that these extinction methods may be extended to additional dark clouds where maser parallaxes are not available.

  17. Samples and data accessibility in research biobanks: an explorative survey

    Directory of Open Access Journals (Sweden)

    Marco Capocasa

    2016-02-01

    Full Text Available Biobanks, which contain human biological samples and/or data, provide a crucial contribution to the progress of biomedical research. However, the effective and efficient use of biobank resources depends on their accessibility. In fact, making bio-resources promptly accessible to everybody may increase the benefits for society. Furthermore, optimizing their use and ensuring their quality will promote scientific creativity and, in general, contribute to the progress of bio-medical research. Although this has become a rather common belief, several laboratories are still secretive and continue to withhold samples and data. In this study, we conducted a questionnaire-based survey in order to investigate sample and data accessibility in research biobanks operating all over the world. The survey involved a total of 46 biobanks. Most of them gave permission to access their samples (95.7% and data (85.4%, but free and unconditioned accessibility seemed not to be common practice. The analysis of the guidelines regarding the accessibility to resources of the biobanks that responded to the survey highlights three issues: (i the request for applicants to explain what they would like to do with the resources requested; (ii the role of funding, public or private, in the establishment of fruitful collaborations between biobanks and research labs; (iii the request of co-authorship in order to give access to their data. These results suggest that economic and academic aspects are involved in determining the extent of sample and data sharing stored in biobanks. As a second step of this study, we investigated the reasons behind the high diversity of requirements to access biobank resources. The analysis of informative answers suggested that the different modalities of resource accessibility seem to be largely influenced by both social context and legislation of the countries where the biobanks operate.

  18. A sample of galaxy pairs identified from the LAMOST spectral survey and the Sloan Digital Sky Survey

    International Nuclear Information System (INIS)

    Shen, Shi-Yin; Argudo-Fernández, Maria; Chen, Li; Feng, Shuai; Hou, Jin-Liang; Shao, Zheng-Yi; Chen, Xiao-Yan; Luo, A-Li; Wu, Hong; Yang, Hai-Feng; Yang, Ming; Hou, Yong-Hui; Wang, Yue-Fei; Jiang, Peng; Wang, Ting-Gui; Jing, Yi-Peng; Kong, Xu; Wang, Wen-Ting; Luo, Zhi-Jian; Wu, Xue-Bing

    2016-01-01

    A small fraction (< 10%) of the SDSS main galaxy (MG) sample has not been targeted with spectroscopy due to the effect of fiber collisions. These galaxies have been compiled into the input catalog of the LAMOST ExtraGAlactic Surveys and named the complementary galaxy sample. In this paper, we introduce this project and status of the spectroscopies associated with the complementary galaxies in the first two years of the LAMOST spectral survey (till Sep. of 2014). Moreover, we present a sample of 1102 galaxy pairs identified from the LAMOST complementary galaxies and SDSS MGs, which are defined as two members that have a projected distance smaller than 100 h −1 70 kpc and a recessional velocity difference smaller than 500 km s −1 . Compared with galaxy pairs that are only selected from SDSS, the LAMOST-SDSS pairs have the advantages of not being biased toward large separations and therefore act as a useful supplement in statistical studies of galaxy interaction and galaxy merging. (paper)

  19. A survey of archaeological and geological samples dated in 1990

    International Nuclear Information System (INIS)

    Mejdahl, V.

    1991-01-01

    A survey of dated archaeological and geological samples is given, using thermoluminescence dating. Some of the sediment samples were also dated by means of optically stimulated luminescence (OSL) using a newly developed infrared diode system. In most cases the luminescence dates are in accordance with archaeological and geological estimates. Some discrepancies were found because some feldspar samples exhibited severe anomalous fading. It may be possible to avoid this problem by basing the dating on OSL of quartz. For sediment samples of Eemian or Early Weichselian age severe underestimates were encountered with both methods. The reason might be related to the large difference between the natural dose rate and that used in laboratory irradiations. Traps corresponding to low-temperature peaks such as the 150 deg. C peak in feldspars will remain almost empty under natural conditions, but will fill up to saturation under laboratory irradiation and thereby more charges will be captured in high-temperature traps. As a result, natural growth curves and laboratory produced luminescence growth curves will have different slopes and this will lead to underestimation. This problem might avoided by holding samples at an elevated temperature during laboratory irradiation, thus keeping the low-temperature traps empty. Preliminary experiments where feldspar samples were held at 130 deg. C during irradiation have given promising results. (AB) (31 refs.)

  20. Human-Robot Site Survey and Sampling for Space Exploration

    Science.gov (United States)

    Fong, Terrence; Bualat, Maria; Edwards, Laurence; Flueckiger, Lorenzo; Kunz, Clayton; Lee, Susan Y.; Park, Eric; To, Vinh; Utz, Hans; Ackner, Nir

    2006-01-01

    NASA is planning to send humans and robots back to the Moon before 2020. In order for extended missions to be productive, high quality maps of lunar terrain and resources are required. Although orbital images can provide much information, many features (local topography, resources, etc) will have to be characterized directly on the surface. To address this need, we are developing a system to perform site survey and sampling. The system includes multiple robots and humans operating in a variety of team configurations, coordinated via peer-to-peer human-robot interaction. In this paper, we present our system design and describe planned field tests.

  1. Needs for and Utilization of OER in Distance Education: A Chinese Survey

    Science.gov (United States)

    Chen, Qing; Panda, Santosh

    2013-01-01

    The recent developments within open educational resources (OERs) and open licensing have generated considerable interest among distance educators since open and distance learning is supposed to be the largest consumer/user of and contributor to OER. In China, given the policy of development and use of elaborate courses, conversion of radio and…

  2. Beliefs of Certified Public Accountants toward Distance Education: A Statewide Georgia Survey.

    Science.gov (United States)

    Perdue, Kathy J.; Valentine, Thomas

    1998-01-01

    Examines the beliefs of certified public accountants (CPAs) in the state of Georgia concerning the effectiveness of distance education in providing continuing professional education (CPE). Findings indicate that the CPAs believe distance education to be an effective mode of learning, and that necessary technological capabilities are available to…

  3. A Simple Device for Lens-to-Sample Distance Adjustment in Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Cortez, Juliana; Farias Filho, Benedito B; Fontes, Laiane M; Pasquini, Celio; Raimundo, Ivo M; Pimentel, Maria Fernanda; de Souza Lins Borba, Flávia

    2017-04-01

    A simple device based on two commercial laser pointers is described to assist in the analysis of samples that present uneven surfaces and/or irregular shapes using laser-induced breakdown spectroscopy (LIBS). The device allows for easy positioning of the sample surface at a reproducible distance from the focusing lens that conveys the laser pulse to generate the micro-plasma in a LIBS system, with reproducibility better than ±0.2 mm. In this way, fluctuations in the fluence (J cm -2 ) are minimized and the LIBS analytical signals can be obtained with a better precision even when samples with irregular surfaces are probed.

  4. Constant-Distance Mode Nanospray Desorption Electrospray Ionization Mass Spectrometry Imaging of Biological Samples with Complex Topography

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Son N.; Liyu, Andrey V.; Chu, Rosalie K.; Anderton, Christopher R.; Laskin, Julia

    2017-01-17

    A new approach for constant distance mode mass spectrometry imaging of biological samples using nanospray desorption electrospray ionization (nano-DESI MSI) was developed by integrating a shear-force probe with nano-DESI probe. The technical concept and basic instrumental setup as well as general operation of the system are described. Mechanical dampening of resonant oscillations due to the presence of shear forces between the probe and the sample surface enables constant-distance imaging mode via a computer controlled closed feedback loop. The capability of simultaneous chemical and topographic imaging of complex biological samples is demonstrated using living Bacillus Subtilis ATCC 49760 colonies on agar plates. The constant-distance mode nano-DESI MSI enabled imaging of many metabolites including non-ribosomal peptides (surfactin, plipastatin and iturin) and iron-bound heme on the surface of living bacterial colonies ranging in diameter from 10 mm to 13 mm with height variations of up to 0.8 mm above the agar plate. Co-registration of ion images to topographic images provided higher-contrast images. Constant-mode nano-DESI MSI is ideally suited for imaging biological samples of complex topography in their native state.

  5. Quantifying the sensitivity of camera traps:an adapted distance sampling approach

    NARCIS (Netherlands)

    Rowcliffe, M.; Carbone, C.; Jansen, P.A.; Kays, R.W.; Kranstauber, B.

    2011-01-01

    1. Abundance estimation is a pervasive goal in ecology. The rate of detection by motion-sensitive camera traps can, in principle, provide information on the abundance of many species of terrestrial vertebrates that are otherwise difficult to survey. The random encounter model (REM, Rowcliffe et al.

  6. A Survey of User Education Program for Distance Learners in Three ...

    African Journals Online (AJOL)

    Information Manager (The) ... This study investigates user education programme for distance learners in three selected university libraries. ... was carried out by their libraries concluded that it impacted positively on their retrieval ability.

  7. Sample selection via angular distance in the space of the arguments of an artificial neural network

    Science.gov (United States)

    Fernández Jaramillo, J. M.; Mayerle, R.

    2018-05-01

    In the construction of an artificial neural network (ANN) a proper data splitting of the available samples plays a major role in the training process. This selection of subsets for training, testing and validation affects the generalization ability of the neural network. Also the number of samples has an impact in the time required for the design of the ANN and the training. This paper introduces an efficient and simple method for reducing the set of samples used for training a neural network. The method reduces the required time to calculate the network coefficients, while keeping the diversity and avoiding overtraining the ANN due the presence of similar samples. The proposed method is based on the calculation of the angle between two vectors, each one representing one input of the neural network. When the angle formed among samples is smaller than a defined threshold only one input is accepted for the training. The accepted inputs are scattered throughout the sample space. Tidal records are used to demonstrate the proposed method. The results of a cross-validation show that with few inputs the quality of the outputs is not accurate and depends on the selection of the first sample, but as the number of inputs increases the accuracy is improved and differences among the scenarios with a different starting sample have and important reduction. A comparison with the K-means clustering algorithm shows that for this application the proposed method with a smaller number of samples is producing a more accurate network.

  8. Not Too Distant: A Survey Of Strategies For Teacher Support In Distance Education Programs

    OpenAIRE

    BURNS, Mary

    2015-01-01

    Distance learning can be a “very lonely” experience (Brown & Early, cited by Prescott & Robinson, 1993). This isolation exacerbates all of the many issues that can occur when learners are separated from their instructor and other learners via distance. Difficulties understanding content, computer problems, uncertainty about how to employ a strategy, and disappointment when a new pedagogical approach fails are all magnified when teachers confront these issues alone. High rates ...

  9. NOT TOO DISTANT: A Survey of Strategies for Teacher Support In Distance Education Programs

    Directory of Open Access Journals (Sweden)

    Mary BURNS

    2010-04-01

    Full Text Available Distance learning can be a “very lonely” experience (Brown & Early, cited by Prescott & Robinson, 1993. This isolation exacerbates all of the many issues that can occur when learners are separated from their instructor and other learners via distance. Difficulties understanding content, computer problems, uncertainty about how to employ a strategy, and disappointment when a new pedagogical approach fails are all magnified when teachers confront these issues alone. High rates of attrition in distance-based teacher training courses are in large measure due to these feelings of isolation and “anonymity” (Potashnik & Capper, 1998; Hope, 2006. Indeed, without “support, contact and confidence,” distance learning is not considered by learners to be “valuable” (Brown & Early, 1990; Prescott & Robinson, 1993, p. 306. This paper presents a recent historical and global overview of the types of supports provided to distance education programs across the globe. Because of the diversity of distance-education programs, the paper includes a range of such modalities (print-based instruction, radio, television, and online learning.

  10. Distance Education and Open Learning in Sub-Saharan Africa: Criteria and Conditions for Quality and Critical Success Factor-- Working Group on Distance Education and Open Learning. A Survey of Policy and Practice. Final Report

    Science.gov (United States)

    Commonwealth of Learning, 2004

    2004-01-01

    Both of these "Surveys of policy and practice" were conducted on behalf of COL by the South African Institute for Distance Education (SAIDE) as part of COL's partnership agreement with the Association for the Development of Education in Africa (ADEA) Working Group on Distance Education and Open Learning. The first report identifies…

  11. Choosing a Cluster Sampling Design for Lot Quality Assurance Sampling Surveys.

    Directory of Open Access Journals (Sweden)

    Lauren Hund

    Full Text Available Lot quality assurance sampling (LQAS surveys are commonly used for monitoring and evaluation in resource-limited settings. Recently several methods have been proposed to combine LQAS with cluster sampling for more timely and cost-effective data collection. For some of these methods, the standard binomial model can be used for constructing decision rules as the clustering can be ignored. For other designs, considered here, clustering is accommodated in the design phase. In this paper, we compare these latter cluster LQAS methodologies and provide recommendations for choosing a cluster LQAS design. We compare technical differences in the three methods and determine situations in which the choice of method results in a substantively different design. We consider two different aspects of the methods: the distributional assumptions and the clustering parameterization. Further, we provide software tools for implementing each method and clarify misconceptions about these designs in the literature. We illustrate the differences in these methods using vaccination and nutrition cluster LQAS surveys as example designs. The cluster methods are not sensitive to the distributional assumptions but can result in substantially different designs (sample sizes depending on the clustering parameterization. However, none of the clustering parameterizations used in the existing methods appears to be consistent with the observed data, and, consequently, choice between the cluster LQAS methods is not straightforward. Further research should attempt to characterize clustering patterns in specific applications and provide suggestions for best-practice cluster LQAS designs on a setting-specific basis.

  12. Choosing a Cluster Sampling Design for Lot Quality Assurance Sampling Surveys.

    Science.gov (United States)

    Hund, Lauren; Bedrick, Edward J; Pagano, Marcello

    2015-01-01

    Lot quality assurance sampling (LQAS) surveys are commonly used for monitoring and evaluation in resource-limited settings. Recently several methods have been proposed to combine LQAS with cluster sampling for more timely and cost-effective data collection. For some of these methods, the standard binomial model can be used for constructing decision rules as the clustering can be ignored. For other designs, considered here, clustering is accommodated in the design phase. In this paper, we compare these latter cluster LQAS methodologies and provide recommendations for choosing a cluster LQAS design. We compare technical differences in the three methods and determine situations in which the choice of method results in a substantively different design. We consider two different aspects of the methods: the distributional assumptions and the clustering parameterization. Further, we provide software tools for implementing each method and clarify misconceptions about these designs in the literature. We illustrate the differences in these methods using vaccination and nutrition cluster LQAS surveys as example designs. The cluster methods are not sensitive to the distributional assumptions but can result in substantially different designs (sample sizes) depending on the clustering parameterization. However, none of the clustering parameterizations used in the existing methods appears to be consistent with the observed data, and, consequently, choice between the cluster LQAS methods is not straightforward. Further research should attempt to characterize clustering patterns in specific applications and provide suggestions for best-practice cluster LQAS designs on a setting-specific basis.

  13. Temporal focus, temporal distance, and mind-wandering valence: Results from an experience sampling and an experimental study.

    Science.gov (United States)

    Spronken, Maitta; Holland, Rob W; Figner, Bernd; Dijksterhuis, Ap

    2016-04-01

    When mind-wandering, people may think about events that happened in the past, or events that may happen in the future. Using experience sampling, we first aimed to replicate the finding that future-oriented thoughts show a greater positivity bias than past-oriented thoughts. Furthermore, we investigated whether there is a relation between the temporal distance of past- and future-oriented thoughts and the frequency of positive thoughts, a factor that has received little attention in previous work. Second, we experimentally investigated the relation between temporal focus, temporal distance, and thought valence. Both studies showed that future-oriented thoughts were more positive compared to past-oriented thoughts. Regarding temporal distance, thoughts about the distant past and future were more positive than thoughts about the near past and future in the experiment. However, the experience sampling study did not provide clear insight into this relation. Potential theoretical and methodological explanations for these findings are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. What does the Tourism Demand Survey tell about long distance travel

    DEFF Research Database (Denmark)

    Christensen, Linda; Nielsen, Otto Anker

    Long distance travel is one of the fastest increasing travel activities with a very high impact on the climate. Nevertheless the demand is scarcely documented from a transport perspective, nationally as well as internationally and policies to reduce the increase in demand are seldom addressed....... This is in sharp contrast to the substantial public and private investments in infrastructure and transport modes for long distance travel by air as well as rail. Furthermore, it is a problem related to the serious environmental impact from air travel (Alonso et al., 2014; Christensen, 2016; Aamaas et al., 2013...

  15. A study of topics for distance education-A survey of U.S. Fish and Wildlife Service employees

    Science.gov (United States)

    Ratz, Joan M.; Schuster, Rudy M.; Marcy, Ann H.

    2011-01-01

    The purpose of this study was to identify training topics and distance education technologies preferred by U.S. Fish and Wildlife Service employees. This study was conducted on behalf of the National Conservation Training Center to support their distance education strategy planning and implementation. When selecting survey recipients, we focused on employees in positions involving conservation and environmental education and outreach programming. We conducted the study in two phases. First, we surveyed 72 employees to identify useful training topics. The response rate was 61 percent; respondents were from all regions and included supervisors and nonsupervisors. Five topics for training were identified: creating and maintaining partnerships (partnerships), technology, program planning and development (program planning), outreach methods to engage the community (outreach methods), and evaluation methods. In the second phase, we surveyed 1,488 employees to assess preferences for training among the five topics identified in the first survey and preferences among six distance education technologies: satellite television, video conferencing, audio conferencing, computer mediated training, written resources, and audio resources. Two types of instructor-led training were included on the survey to compare to the technology options. Respondents were asked what types of information, such as basic facts or problem solving skills, were needed for each of the five topics. The adjusted response rate was 64 percent; respondents were from all regions and included supervisors and nonsupervisors. The results indicated clear preferences among respondents for certain training topics and technologies. All five training topics were valued, but the topics of partnerships and technology were given equal value and were valued more than the other three topics. Respondents indicated a desire for training on the topics of partnerships, technology, program planning, and outreach methods. For

  16. Field results for line intersect distance sampling of coarse woody debris

    Science.gov (United States)

    David L. R. Affleck

    2009-01-01

    A growing recognition of the importance of downed woody materials in forest ecosystem processes and global carbon budgets has sharpened the need for efficient sampling strategies that target this resource. Often the aggregate volume, biomass, or carbon content of the downed wood is of primary interest, making recently developed probability proportional-to-volume...

  17. THE CHANDRA COSMOS-LEGACY SURVEY: THE z > 3 SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Marchesi, S.; Civano, F.; Urry, C. M. [Yale Center for Astronomy and Astrophysics, 260 Whitney Avenue, New Haven, CT 06520 (United States); Salvato, M. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching bei München (Germany); Shankar, F. [Department of Physics and Astronomy, University of Southampton, Highfield, SO17 1BJ (United Kingdom); Comastri, A.; Lanzuisi, G.; Vignali, C.; Zamorani, G.; Brusa, M.; Gilli, R. [INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna (Italy); Elvis, M. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Trakhtenbrot, B.; Schawinski, K. [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Allevato, V. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland); Fiore, F. [INAF–Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monte Porzio Catone (Italy); Griffiths, R. [Physics and Astronomy Department, Natural Sciences Division, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, HI 96720 (United States); Hasinger, G. [Institute for Astronomy, 2680 Woodlawn Drive, University of Hawaii, Honolulu, HI 96822 (United States); Miyaji, T. [Instituto de Astronomía sede Ensenada, Universidad Nacional Autónoma de México, Km. 103, Carret. Tijunana-Ensenada, Ensenada, BC (Mexico); Treister, E. [Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción (Chile)

    2016-08-20

    We present the largest high-redshift (3 < z < 6.85) sample of X-ray-selected active galactic nuclei (AGNs) on a contiguous field, using sources detected in the Chandra COSMOS-Legacy survey. The sample contains 174 sources, 87 with spectroscopic redshift and the other 87 with photometric redshift (z {sub phot}). In this work, we treat z {sub phot} as a probability-weighted sum of contributions, adding to our sample the contribution of sources with z {sub phot} < 3 but z {sub phot} probability distribution >0 at z > 3. We compute the number counts in the observed 0.5–2 keV band, finding a decline in the number of sources at z > 3 and constraining phenomenological models of the X-ray background. We compute the AGN space density at z > 3 in two different luminosity bins. At higher luminosities (log L (2–10 keV) > 44.1 erg s{sup −1}), the space density declines exponentially, dropping by a factor of ∼20 from z ∼ 3 to z ∼ 6. The observed decline is ∼80% steeper at lower luminosities (43.55 erg s{sup −1} < logL(2–10 keV) < 44.1 erg s{sup −1}) from z ∼ 3 to z ∼ 4.5. We study the space density evolution dividing our sample into optically classified Type 1 and Type 2 AGNs. At log L (2–10 keV) > 44.1 erg s{sup −1}, unobscured and obscured objects may have different evolution with redshift, with the obscured component being three times higher at z ∼ 5. Finally, we compare our space density with predictions of quasar activation merger models, whose calibration is based on optically luminous AGNs. These models significantly overpredict the number of expected AGNs at log L (2–10 keV) > 44.1 erg s{sup −1} with respect to our data.

  18. Small Population Size of the Pribilof Rock Sandpiper Confirmed through Distance-Sampling Surveys in Alaska

    NARCIS (Netherlands)

    Ruthrauff, D.R.; Tibbitts, T.L.; Gill, R.E.; Dementyev, M.N.

    2012-01-01

    The Rock Sandpiper (Calidris ptilocnemis) is endemic to the Bering Sea region and unique among shorebirds in the North Pacific for wintering at high latitudes. The nominate subspecies, the Pribilof Rock Sandpiper (C. p. ptilocnemis), breeds on four isolated islands in the Bering Sea and appears to

  19. A Study on the Representative Sampling Survey for Radionuclide Analysis of RI Waste

    Energy Technology Data Exchange (ETDEWEB)

    Jee, K. Y. [KAERI, Daejeon (Korea, Republic of); Kim, Juyoul; Jung, Gunhyo [FNC Tech. Co., Daejeon (Korea, Republic of)

    2007-07-15

    We developed a quantitative method for attaining a representative sample during sampling survey of RI waste. Considering a source, process, and type of RI waste, the method computes the number of sample, confidence interval, variance, and coefficient of variance. We also systematize the method of sampling survey logically and quantitatively. The result of this study can be applied to sampling survey of low- and intermediate-level waste generated from nuclear power plant during the transfer process to disposal facility.

  20. Measurements of tritium (HTO, TFWT, OBT) in environmental samples at varying distances from a nuclear generating station

    International Nuclear Information System (INIS)

    Kotzer, T.G.; Workman, W.J.G.

    1999-12-01

    Concentrations of tritium have been measured in environmental samples (vegetation, water, soil, air) from sites distal and proximal to a CANDU nuclear generating station in Southern Ontario (OPG-Pickering). Levels of tissue-free water tritium (TFWT) and organically bound tritium (OBT) in vegetation are as high as 24,000 TU immediately adjacent to the nuclear generating station and rapidly decrease to levels of tritium which are comparable to natural ambient concentrations for tritium in the environment (approximately ≤ 60 TU). Tritium concentrations (OBT, TFTW) have also been measured in samples of vegetation and tree rings growing substantial distances away from nuclear generating stations and are within a factor of 1 to 2 of the ambient levels of tritium measured in precipitation in several parts of Canada (approximately ≤30 TU). (author)

  1. Measurements of tritium (HTO, TFWT, OBT) in environmental samples at varying distances from a nuclear generating station

    Energy Technology Data Exchange (ETDEWEB)

    Kotzer, T.G.; Workman, W.J.G

    1999-12-01

    Concentrations of tritium have been measured in environmental samples (vegetation, water, soil, air) from sites distal and proximal to a CANDU nuclear generating station in Southern Ontario (OPG-Pickering). Levels of tissue-free water tritium (TFWT) and organically bound tritium (OBT) in vegetation are as high as 24,000 TU immediately adjacent to the nuclear generating station and rapidly decrease to levels of tritium which are comparable to natural ambient concentrations for tritium in the environment (approximately {<=} 60 TU). Tritium concentrations (OBT, TFTW) have also been measured in samples of vegetation and tree rings growing substantial distances away from nuclear generating stations and are within a factor of 1 to 2 of the ambient levels of tritium measured in precipitation in several parts of Canada (approximately {<=}30 TU). (author)

  2. Are Italian medical societies bridging the distance from citizen and patients' associations? Results of a survey.

    Science.gov (United States)

    Mosconi, P; Colombo, C; Guella, F; Pierotti, B; Vimercati, F

    2008-09-01

    In the framework of PartecipaSalute--an Italian research project aimed to involve lay people, patients' associations and scientific-medical representatives on the health debate --we carried out a survey with the Italian Federation of Medical Societies. The aims of the survey were to know medical societies attitude vs. patients involvement in research activities and healthcare setting and to find out possible projects conducted in partnership with patients associations. A web-questionnaire with 17 closed questions, and three open questions has been prepared on the basis of some experiences published on the literature and through the collaboration of members of the Italian Federation of Medical Societies. A total of 205 medical societies has been contacted by e-mail with a cover letter explaining the aims of the survey. At the end 74 medical societies completed the survey. Medical societies participating to the survey varied widely in terms of years of activity, number of members, and geographical distribution. Remarkably, 36 medical societies respondent organized collaborative initiatives with patients/consumers associations during the last three years. Among these, the most frequent were the preparation of written material for patients, organization of conferences or workshops, and health awareness campaigns. Moreover, 6 medical societies published documents on patients' rights but patients or their associations were involved in only 2 of these initiatives. Advantages and disadvantages reported by medical societies answering are also presented and discussed. In conclusion, to our knowledge this is the first survey on the value of patients' involvement conducted together with medical societies in Italy, and the results point the way to stronger collaboration in future between patients' associations and medical societies.

  3. Optimal Allocation of Sampling Effort in Depletion Surveys

    Science.gov (United States)

    We consider the problem of designing a depletion or removal survey as part of estimating animal abundance for populations with imperfect capture or detection rates. In a depletion survey, animals are captured from a given area, counted, and withheld from the population. This proc...

  4. International survey blauwe wijting. Elke seconde een sample

    NARCIS (Netherlands)

    Faessler, S.M.M.

    2011-01-01

    IJMuiden- in 2011 wordt voor het eerst de jaarlijkse blauwe wijting survey gecoördineerd door Schascha Fässler, geboren Zwitser en sinds 2009 als 'fisheries acoustics' scientist' werkzaam bij IMARES in IJmuiden. In onderstaand artikel gaat Fässler nader in op acoustics in het algemeen en de survey

  5. Understanding Sample Surveys: Selective Learning about Social Science Research Methods

    Science.gov (United States)

    Currin-Percival, Mary; Johnson, Martin

    2010-01-01

    We investigate differences in what students learn about survey methodology in a class on public opinion presented in two critically different ways: with the inclusion or exclusion of an original research project using a random-digit-dial telephone survey. Using a quasi-experimental design and data obtained from pretests and posttests in two public…

  6. Costing Distance Education and Open Learning in Sub-Saharan Africa: Working Group on Distance Education and Open Learning-- A Survey of Policy and Practice. Final Report

    Science.gov (United States)

    Commonwealth of Learning, 2004

    2004-01-01

    Ideological arguments are made for open learning, economic ones for distance education. If it can produce similar results to those of conventional education at a lower cost, then distance education has a powerful appeal. With increasing demand for access to educational opportunities at all levels, and often decreasing budgets in real terms for…

  7. Surveying immigrants without sampling frames - evaluating the success of alternative field methods.

    Science.gov (United States)

    Reichel, David; Morales, Laura

    2017-01-01

    This paper evaluates the sampling methods of an international survey, the Immigrant Citizens Survey, which aimed at surveying immigrants from outside the European Union (EU) in 15 cities in seven EU countries. In five countries, no sample frame was available for the target population. Consequently, alternative ways to obtain a representative sample had to be found. In three countries 'location sampling' was employed, while in two countries traditional methods were used with adaptations to reach the target population. The paper assesses the main methodological challenges of carrying out a survey among a group of immigrants for whom no sampling frame exists. The samples of the survey in these five countries are compared to results of official statistics in order to assess the accuracy of the samples obtained through the different sampling methods. It can be shown that alternative sampling methods can provide meaningful results in terms of core demographic characteristics although some estimates differ to some extent from the census results.

  8. Seasonal associations and atmospheric transport distances of Fusarium collected with unmanned aerial vehicles and ground-based sampling devices

    Science.gov (United States)

    Schmale, David; Ross, Shane; Lin, Binbin

    2014-05-01

    Spores of fungi in the genus Fusarium may be transported through the atmosphere over long distances. Members of this genus are important pathogens and mycotoxin producers. New information is needed to characterize seasonal trends in atmospheric loads of Fusarium and to pinpoint the source(s) of inoculum at both local (farm) and regional (state or country) scales. Spores of Fusarium were collected from the atmosphere in an agricultural ecosystem in Blacksburg, VA, USA using a Burkard volumetric sampler (BVS) 1 m above ground level and autonomous unmanned aerial vehicles (UAVs) 100 m above ground level. More than 2,200 colony forming units (CFUs) of Fusarium were collected during 104 BVS sampling periods and 180 UAV sampling periods over four calendar years (2009-2012). Spore concentrations ranged from 0 to 13 and 0 to 23 spores m-3 for the BVS and the UAVs, respectively. Spore concentrations were generally higher in the fall, spring, and summer, and lower in the winter. Spore concentrations from the BVS were generally higher than those from the UAVs for both seasonal and hourly collections. Some of the species of Fusarium identified from our collections have not been previously reported in the state of Virginia. A Gaussian plume transport model was used to estimate distances to the potential inoculum source(s) by season. This work extends previous studies showing an association between atmospheric transport barriers (Lagrangian coherent structures or LCSs) and the movement of Fusarium in the lower atmosphere. An increased understanding of the aerobiology of Fusarium may contribute to new and improved control strategies for diseases causes by fusaria in the future.

  9. A two-phase sampling survey for nonresponse and its paradata to correct nonresponse bias in a health surveillance survey.

    Science.gov (United States)

    Santin, G; Bénézet, L; Geoffroy-Perez, B; Bouyer, J; Guéguen, A

    2017-02-01

    The decline in participation rates in surveys, including epidemiological surveillance surveys, has become a real concern since it may increase nonresponse bias. The aim of this study is to estimate the contribution of a complementary survey among a subsample of nonrespondents, and the additional contribution of paradata in correcting for nonresponse bias in an occupational health surveillance survey. In 2010, 10,000 workers were randomly selected and sent a postal questionnaire. Sociodemographic data were available for the whole sample. After data collection of the questionnaires, a complementary survey among a random subsample of 500 nonrespondents was performed using a questionnaire administered by an interviewer. Paradata were collected for the complete subsample of the complementary survey. Nonresponse bias in the initial sample and in the combined samples were assessed using variables from administrative databases available for the whole sample, not subject to differential measurement errors. Corrected prevalences by reweighting technique were estimated by first using the initial survey alone and then the initial and complementary surveys combined, under several assumptions regarding the missing data process. Results were compared by computing relative errors. The response rates of the initial and complementary surveys were 23.6% and 62.6%, respectively. For the initial and the combined surveys, the relative errors decreased after correction for nonresponse on sociodemographic variables. For the combined surveys without paradata, relative errors decreased compared with the initial survey. The contribution of the paradata was weak. When a complex descriptive survey has a low response rate, a short complementary survey among nonrespondents with a protocol which aims to maximize the response rates, is useful. The contribution of sociodemographic variables in correcting for nonresponse bias is important whereas the additional contribution of paradata in

  10. 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

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

    Science.gov (United States)

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

    2018-01-01

    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. 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. 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. 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 comparison to household surveys. Random digit dialing of mobile

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

    Directory of Open Access Journals (Sweden)

    Kelly L'Engle

    Full Text Available 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.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.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.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 comparison to household surveys. Random digit

  13. Risk behaviour, sexually transmitted infections and HIV among long-distance truck drivers: a cross-sectional survey along national highways in India.

    Science.gov (United States)

    Pandey, Arvind; Benara, Sudhir Kumar; Roy, Nandini; Sahu, Damodar; Thomas, Mariamma; Joshi, Dhirendra Kumar; Sengupta, Utpal; Paranjape, Ramesh S; Bhalla, Aparajita; Prakash, Ajay

    2008-12-01

    To report HIV and sexually transmitted infection (STI) prevalence and sexual behaviour of long-distance truckers on four national highway routes from a large, cross-sectional, national-level trucker survey in India. Seven trans-shipment locations covering the bulk of India's transport volume along four routes, north-west (NW), north-south (NS), north-east (NE) and south-east (SE) were identified as survey sites. A total of 2066 long-distance truckers were selected using a two-stage, time-location cluster sampling approach and, after consent, interviewed about their sexual behaviour. Urine and blood sample were tested for selected STIs. Overall, HIV prevalence among truckers was found to be 4.6%, with prevalence highest on the SE route (6.8%) and lowest on the NS (2.4%). Positive HSV-2 serology, which was tested in a 10% subsample, was low along three routes, 10.0%, 12.8% and 6.7% for the NE, NS and NW, respectively, but 38.7% in the SE. The truckers from the SE were found to be more likely to have sex with paid partners than the NE route. Moreover, truckers who owned their trucks were more likely than those who did not use condoms consistently with paid partners, and truckers who drive trucks owned by their relatives/friends are more likely than others to have any STI. Low self-risk perception for HIV (9.9%), low consistent condom use with non-paid partners (18.6%) and wives (3%), low reported exposure to any interventions (25.6%) and low levels of ever having taken an HIV test (16.5%) make truckers an important bridge population requiring strengthened interventions.

  14. Dark Energy Survey Year 1 Results: Galaxy Sample for BAO Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Crocce, M.; et al.

    2017-12-17

    We define and characterise a sample of 1.3 million galaxies extracted from the first year of Dark Energy Survey data, optimised to measure Baryon Acoustic Oscillations in the presence of significant redshift uncertainties. The sample is dominated by luminous red galaxies located at redshifts $z \\gtrsim 0.6$. We define the exact selection using color and magnitude cuts that balance the need of high number densities and small photometric redshift uncertainties, using the corresponding forecasted BAO distance error as a figure-of-merit in the process. The typical photo-$z$ uncertainty varies from $2.3\\%$ to $3.6\\%$ (in units of 1+$z$) from $z=0.6$ to $1$, with number densities from $200$ to $130$ galaxies per deg$^2$ in tomographic bins of width $\\Delta z = 0.1$. Next we summarise the validation of the photometric redshift estimation. We characterise and mitigate observational systematics including stellar contamination, and show that the clustering on large scales is robust in front of those contaminants. We show that the clustering signal in the auto-correlations and cross-correlations is generally consistent with theoretical models, which serves as an additional test of the redshift distributions.

  15. Communication Problems in Turner Syndrome: A Sample Survey.

    Science.gov (United States)

    Van Borsel, John; Dhooge, Inge; Verhoye, Kristof; Derde, Kristel; Curfs, Leopold

    1999-01-01

    A survey of 128 females (ages 2-58) with Turner syndrome found almost one quarter were receiving or had received treatment for stuttering, articulation problems, and/or delayed language development, with the latter two disorders being checked most frequently. Only 4 or the 68 individuals receiving growth hormone treatment reported voice changes.…

  16. Sample Size Calculations for Population Size Estimation Studies Using Multiplier Methods With Respondent-Driven Sampling Surveys.

    Science.gov (United States)

    Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R

    2017-09-14

    While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey. ©Elizabeth Fearon, Sungai T Chabata, Jennifer A Thompson, Frances M Cowan, James R Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 14.09.2017.

  17. A survey of U.S. Fish and Wildlife Service employees regarding topics for distance education-Summary report to respondents

    Science.gov (United States)

    Ratz, Joan M.; Shuster, Rudy M.; Marcy, Ann M.

    2011-01-01

    This report provides a summary of responses to the questions included in the U.S. Fish and Wildlife Service (FWS) National Conservation Training Center (NCTC) Distance Education survey conducted from January 26, 2010, to February 8, 2010. The survey included questions for two studies sponsored by the Division of Education Outreach (DEO) at the NCTC. The first study identifies the topics of interest to FWS employees on which training could be provided via distance education. The topics were limited to the area of conservation and environmental education, outreach, and partnerships because these topics are within the scope of the DEO. The second study focused on characterizing the relation between onsite course enrollment at NCTC and distance education offerings. Because there were only a few questions on the survey for the second study and because the target populations were the same for both, the two surveys were combined.

  18. Representing distance, consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    Title: Representing Distance, Consuming Distance Abstract: Distance is a condition for corporeal and virtual mobilities, for desired and actual travel, but yet it has received relatively little attention as a theoretical entity in its own right. Understandings of and assumptions about distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...

  19. A redshift survey of IRAS galaxies. I. Sample selection

    International Nuclear Information System (INIS)

    Strauss, M.A.; Davis, M.; Yahil, A.; Huchra, J.P.

    1990-01-01

    A complete all-sky sample of objects, flux-limited at 60 microns, has been extracted from the data base of the IRAS. The sample consists of 5014 objects, of which 2649 are galaxies and 13 are not yet identified. In order to study large-scale structure with this sample, it must be free of systematic biases. Corrections are applied for a major systematic effect in the flux densities listed in the IRAS Point Source Catalog: sources resolved by the IRAS beam have flux densities systematically underestimated. In addition, accurate flux densities are obtained for sources flagged as variable, or of moderate flux quality at 60 microns. The IRAS detectors suffered radiation-induced responsivity enhancement (hysteresis) due to crossings of the satellite scans across the Galactic plane; this effect is measured and is shown to be negligible. 53 refs

  20. A Systematic Review of Published Respondent-Driven Sampling Surveys Collecting Behavioral and Biologic Data.

    Science.gov (United States)

    Johnston, Lisa G; Hakim, Avi J; Dittrich, Samantha; Burnett, Janet; Kim, Evelyn; White, Richard G

    2016-08-01

    Reporting key details of respondent-driven sampling (RDS) survey implementation and analysis is essential for assessing the quality of RDS surveys. RDS is both a recruitment and analytic method and, as such, it is important to adequately describe both aspects in publications. We extracted data from peer-reviewed literature published through September, 2013 that reported collected biological specimens using RDS. We identified 151 eligible peer-reviewed articles describing 222 surveys conducted in seven regions throughout the world. Most published surveys reported basic implementation information such as survey city, country, year, population sampled, interview method, and final sample size. However, many surveys did not report essential methodological and analytical information for assessing RDS survey quality, including number of recruitment sites, seeds at start and end, maximum number of waves, and whether data were adjusted for network size. Understanding the quality of data collection and analysis in RDS is useful for effectively planning public health service delivery and funding priorities.

  1. Community-based survey versus sentinel site sampling in ...

    African Journals Online (AJOL)

    rural children. Implications for nutritional surveillance and the development of nutritional programmes. G. c. Solarsh, D. M. Sanders, C. A. Gibson, E. Gouws. A study of the anthropometric status of under-5-year-olds was conducted in the Nqutu district of Kwazulu by means of a representative community-based sample and.

  2. On The Use Of Network Sampling In Diabetic Surveys | Nafiu ...

    African Journals Online (AJOL)

    Two estimators: Hansen-Hurwitz estimator and Horvitz-Thompson estimator were considered; and the results were obtained using a program written in Microsoft Visual C++ programming language. Keywords: Graph, Sampling Frame, Households, Hansen-Hurwitz estimator and Horvitz-Thompson estimator. JORIND Vol.

  3. Statistical sampling strategies for survey of soil contamination

    NARCIS (Netherlands)

    Brus, D.J.

    2011-01-01

    This chapter reviews methods for selecting sampling locations in contaminated soils for three situations. In the first situation a global estimate of the soil contamination in an area is required. The result of the surey is a number or a series of numbers per contaminant, e.g. the estimated mean

  4. Sample Loss and Survey Bias in Estimates of Social Security Beneficiaries: A Tale of Two Surveys.

    OpenAIRE

    John L. Czajka; James Mabli; Scott Cody

    2008-01-01

    Data from the Census Bureau’s Survey of Income and Program Participation (SIPP) and the Current Population Survey (CPS) provide information on current and potential beneficiaries served by Social Security Administration (SSA) programs. SSA also links administrative records to the records of survey respondents who provide Social Security numbers. These matched data expand the content of the SIPP and CPS files to fields available only through SSA and Internal Revenue Service records—such as l...

  5. 36 CFR 9.42 - Well records and reports, plots and maps, samples, tests and surveys.

    Science.gov (United States)

    2010-07-01

    ... Well records and reports, plots and maps, samples, tests and surveys. Any technical data gathered... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Well records and reports, plots and maps, samples, tests and surveys. 9.42 Section 9.42 Parks, Forests, and Public Property...

  6. National Sample Survey of Registered Nurses II. Status of Nurses: November 1980.

    Science.gov (United States)

    Bentley, Barbara S.; And Others

    This report provides data describing the nursing population as determined by the second national sample survey of registered nurses. A brief introduction is followed by a chapter that presents an overview of the survey methodology, including details on the sampling design, the response rate, and the statistical reliability. Chapter 3 provides a…

  7. Comfortable Interpersonal Distance: Aspects of the Interpersonal Behaviour in a Sample of 16-Year-Old Subjects, Males and Females.

    Science.gov (United States)

    Comunian, Anna Laura

    According to Duke and Newicki, the distance maintained by a subject towards an approach stimulus is closely related to the internal structures of his personality. The test puts the subject's projective personality and the perception that the group has of the subject into relief. Duke and Newiski's "Comfortable Interpersonal Distance"…

  8. Lot quality assurance sampling techniques in health surveys in developing countries: advantages and current constraints.

    Science.gov (United States)

    Lanata, C F; Black, R E

    1991-01-01

    Traditional survey methods, which are generally costly and time-consuming, usually provide information at the regional or national level only. The utilization of lot quality assurance sampling (LQAS) methodology, developed in industry for quality control, makes it possible to use small sample sizes when conducting surveys in small geographical or population-based areas (lots). This article describes the practical use of LQAS for conducting health surveys to monitor health programmes in developing countries. Following a brief description of the method, the article explains how to build a sample frame and conduct the sampling to apply LQAS under field conditions. A detailed description of the procedure for selecting a sampling unit to monitor the health programme and a sample size is given. The sampling schemes utilizing LQAS applicable to health surveys, such as simple- and double-sampling schemes, are discussed. The interpretation of the survey results and the planning of subsequent rounds of LQAS surveys are also discussed. When describing the applicability of LQAS in health surveys in developing countries, the article considers current limitations for its use by health planners in charge of health programmes, and suggests ways to overcome these limitations through future research. It is hoped that with increasing attention being given to industrial sampling plans in general, and LQAS in particular, their utilization to monitor health programmes will provide health planners in developing countries with powerful techniques to help them achieve their health programme targets.

  9. Enhancing sampling design in mist-net bat surveys by accounting for sample size optimization

    OpenAIRE

    Trevelin, Leonardo Carreira; Novaes, Roberto Leonan Morim; Colas-Rosas, Paul François; Benathar, Thayse Cristhina Melo; Peres, Carlos A.

    2017-01-01

    The advantages of mist-netting, the main technique used in Neotropical bat community studies to date, include logistical implementation, standardization and sampling representativeness. Nonetheless, study designs still have to deal with issues of detectability related to how different species behave and use the environment. Yet there is considerable sampling heterogeneity across available studies in the literature. Here, we approach the problem of sample size optimization. We evaluated the co...

  10. THE ALFALFA H α SURVEY. I. PROJECT DESCRIPTION AND THE LOCAL STAR FORMATION RATE DENSITY FROM THE FALL SAMPLE

    International Nuclear Information System (INIS)

    Sistine, Angela Van; Salzer, John J.; Janowiecki, Steven; Sugden, Arthur; Giovanelli, Riccardo; Haynes, Martha P.; Jaskot, Anne E.; Wilcots, Eric M.

    2016-01-01

    The ALFALFA H α survey utilizes a large sample of H i-selected galaxies from the ALFALFA survey to study star formation (SF) in the local universe. ALFALFA H α contains 1555 galaxies with distances between ∼20 and ∼100 Mpc. We have obtained continuum-subtracted narrowband H α images and broadband R images for each galaxy, creating one of the largest homogeneous sets of H α images ever assembled. Our procedures were designed to minimize the uncertainties related to the calculation of the local SF rate density (SFRD). The galaxy sample we constructed is as close to volume-limited as possible, is a robust statistical sample, and spans a wide range of galaxy environments. In this paper, we discuss the properties of our Fall sample of 565 galaxies, our procedure for deriving individual galaxy SF rates, and our method for calculating the local SFRD. We present a preliminary value of log(SFRD[ M ⊙ yr −1 Mpc −3 ]) = −1.747 ± 0.018 (random) ±0.05 (systematic) based on the 565 galaxies in our Fall sub-sample. Compared to the weighted average of SFRD values around z ≈ 2, our local value indicates a drop in the global SFRD of a factor of 10.2 over that lookback time.

  11. THE ALFALFA H α SURVEY. I. PROJECT DESCRIPTION AND THE LOCAL STAR FORMATION RATE DENSITY FROM THE FALL SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Sistine, Angela Van [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Salzer, John J.; Janowiecki, Steven [Department of Astronomy, Indiana University, Bloomington, IN 47405 (United States); Sugden, Arthur [Department of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115 (United States); Giovanelli, Riccardo; Haynes, Martha P. [Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853 (United States); Jaskot, Anne E. [Department of Astronomy, Smith College, Northampton, MA 01063 (United States); Wilcots, Eric M. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2016-06-10

    The ALFALFA H α survey utilizes a large sample of H i-selected galaxies from the ALFALFA survey to study star formation (SF) in the local universe. ALFALFA H α contains 1555 galaxies with distances between ∼20 and ∼100 Mpc. We have obtained continuum-subtracted narrowband H α images and broadband R images for each galaxy, creating one of the largest homogeneous sets of H α images ever assembled. Our procedures were designed to minimize the uncertainties related to the calculation of the local SF rate density (SFRD). The galaxy sample we constructed is as close to volume-limited as possible, is a robust statistical sample, and spans a wide range of galaxy environments. In this paper, we discuss the properties of our Fall sample of 565 galaxies, our procedure for deriving individual galaxy SF rates, and our method for calculating the local SFRD. We present a preliminary value of log(SFRD[ M {sub ⊙} yr{sup −1} Mpc{sup −3}]) = −1.747 ± 0.018 (random) ±0.05 (systematic) based on the 565 galaxies in our Fall sub-sample. Compared to the weighted average of SFRD values around z ≈ 2, our local value indicates a drop in the global SFRD of a factor of 10.2 over that lookback time.

  12. Novel platform for ocean survey and autonomous sampling using multi-agent system

    OpenAIRE

    Taher, Tawfiq; Weymouth, G.D.; Varghese, Tony

    2013-01-01

    In-situ surveying and sampling of ocean environments provides critical data for laboratory work and oceanographic research. However, sampling a time-varying ocean field is often time and resource limited-meaning that samples often miss the features of interest. This paper presents a modular autonomous multi-agent robotic system which has been developed to accommodate a variety of research activities. This paper demonstrates the complementary capabilities of the agents by simultaneously survey...

  13. Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope

    International Nuclear Information System (INIS)

    Santamaria, L.; Siller, H. R.; Garcia-Ortiz, C. E.; Cortes, R.; Coello, V.

    2016-01-01

    In this work, we present an alternative optical method to determine the probe-sample separation distance in a scanning near-field optical microscope. The experimental method is based in a Lloyd’s mirror interferometer and offers a measurement precision deviation of ∼100 nm using digital image processing and numerical analysis. The technique can also be strategically combined with the characterization of piezoelectric actuators and stability evaluation of the optical system. It also opens the possibility for the development of an automatic approximation control system valid for probe-sample distances from 5 to 500 μm.

  14. Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope

    Energy Technology Data Exchange (ETDEWEB)

    Santamaria, L.; Siller, H. R. [Tecnológico de Monterrey, Eugenio Garza Sada 2501 Sur, Monterrey, N.L., 64849 (Mexico); Garcia-Ortiz, C. E., E-mail: cegarcia@cicese.mx [CONACYT Research Fellow – CICESE, Unidad Monterrey, Alianza Centro 504, Apodaca, NL, 66629 (Mexico); Cortes, R.; Coello, V. [CICESE, Unidad Monterrey, PIIT, Alianza Centro 504, Apodaca, NL, 66629 (Mexico)

    2016-04-15

    In this work, we present an alternative optical method to determine the probe-sample separation distance in a scanning near-field optical microscope. The experimental method is based in a Lloyd’s mirror interferometer and offers a measurement precision deviation of ∼100 nm using digital image processing and numerical analysis. The technique can also be strategically combined with the characterization of piezoelectric actuators and stability evaluation of the optical system. It also opens the possibility for the development of an automatic approximation control system valid for probe-sample distances from 5 to 500 μm.

  15. Geochemical drainage surveys for uranium: sampling and analytical methods based on trial surveys in Pennsylvania

    International Nuclear Information System (INIS)

    Rose, A.W.; Keith, M.L.; Suhr, N.H.

    1976-01-01

    Geochemical surveys near sandstone-type uranium prospects in northeastern and north-central Pennsylvania show that the deposits can be detected by carefully planned stream sediment surveys, but not by stream water surveys. Stream waters at single sites changed in U content by x10 to 50 during the 18 months of our studies, and even near known prospects, contain less than 0.2 ppB U most of the time. Uranium extractable from stream sediment by acetic acid--H 2 O 2 provides useful contrast between mineralized and nonmineralized drainages of a square mile or less; total U in sediment does not. High organic material results in increased U content of sediments and must be corrected. Changes in U content of sediment with time reach a maximum of x3 and appear to be of short duration. A sediment of about 200 mi 2 near Jim Thorpe detects anomalies extending over several square miles near known occurrences and a second anomaly about two miles northeast of Penn Haven Jct. A similar survey in Lycoming-Sullivan Counties shows anomalous zones near known prospects of the Beaver Lake area and northwest of Muncy Creek. As, Mn, Pb, and V are enriched in the mineralized zones, and perhaps in surrounding halo zones, but do not appear to be pathfinder elements useful for reconnaissance exploration

  16. Global review of health care surveys using lot quality assurance sampling (LQAS), 1984-2004.

    Science.gov (United States)

    Robertson, Susan E; Valadez, Joseph J

    2006-09-01

    We conducted a global review on the use of lot quality assurance sampling (LQAS) to assess health care services, health behaviors, and disease burden. Publications and reports on LQAS surveys were sought from Medline and five other electronic databases; the World Health Organization; the World Bank; governments, nongovernmental organizations, and individual scientists. We identified a total of 805 LQAS surveys conducted by different management groups during January 1984 through December 2004. There was a striking increase in the annual number of LQAS surveys conducted in 2000-2004 (128/year) compared with 1984-1999 (10/year). Surveys were conducted in 55 countries, and in 12 of these countries there were 10 or more LQAS surveys. Geographically, 317 surveys (39.4%) were conducted in Africa, 197 (28.5%) in the Americas, 115 (14.3%) in the Eastern Mediterranean, 114 (14.2%) in South-East Asia, 48 (6.0%) in Europe, and 14 (1.8%) in the Western Pacific. Health care parameters varied, and some surveys assessed more than one parameter. There were 320 surveys about risk factors for HIV/AIDS/sexually transmitted infections; 266 surveys on immunization coverage, 240 surveys post-disasters, 224 surveys on women's health, 142 surveys on growth and nutrition, 136 surveys on diarrheal disease control, and 88 surveys on quality management. LQAS surveys to assess disease burden included 23 neonatal tetanus mortality surveys and 12 surveys on other diseases. LQAS is a practical field method which increasingly is being applied in assessment of preventive and curative health services, and may offer new research opportunities to social scientists. When LQAS data are collected recurrently at multiple time points, they can be used to measure the spatial variation in behavior change. Such data provide insight into understanding relationships between various investments in social, human, and physical capital, and into the effectiveness of different public health strategies in achieving

  17. Small-vessel Survey and Auction Sampling to Estimate Growth and Maturity of Eteline Snappers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Small-vessel Survey and Auction Sampling to Estimate Growth and Maturity of Eteline Snappers and Improve Data-Limited Stock Assessments. This biosampling project...

  18. Shorlist Masterplan Wind. Evaluation of the sampling grid of the year-round ichthyoplankton survey

    NARCIS (Netherlands)

    Bolle, L.J.; Beek, van J.K.L.

    2011-01-01

    Within the research programme 'Shortlist Masterplan Wind' a year-round ichthyoplankton survey is being carried out. The sampling area is based on known spawning concentrations and prevailing currents.

  19. Evaluating the quality of sampling frames used in European cross-national surveys

    NARCIS (Netherlands)

    Maineri, A.M.; Scherpenzeel, A.; Bristle, Johanna; Pflüger, Senta-Melissa; Butt, Sarah; Zins, Stefan; Emery, Tom; Luijkx, R.

    This report addresses the quality of the population registers which are currently being used as sampling frames in countries participating in the four cross-European surveys cooperating in SERISS: the European Social Survey (ESS), the European Values Study (EVS), the Gender and Generations Program

  20. Effects of sample survey design on the accuracy of classification tree models in species distribution models

    Science.gov (United States)

    Thomas C. Edwards; D. Richard Cutler; Niklaus E. Zimmermann; Linda Geiser; Gretchen G. Moisen

    2006-01-01

    We evaluated the effects of probabilistic (hereafter DESIGN) and non-probabilistic (PURPOSIVE) sample surveys on resultant classification tree models for predicting the presence of four lichen species in the Pacific Northwest, USA. Models derived from both survey forms were assessed using an independent data set (EVALUATION). Measures of accuracy as gauged by...

  1. THE BOLOCAM GALACTIC PLANE SURVEY. XII. DISTANCE CATALOG EXPANSION USING KINEMATIC ISOLATION OF DENSE MOLECULAR CLOUD STRUCTURES WITH {sup 13}CO(1-0)

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth-Bowers, Timothy P.; Glenn, Jason [CASA, University of Colorado, UCB 389, Boulder, CO 80309 (United States); Rosolowsky, Erik [Department of Physics, 4-183 CCIS, University of Alberta, Edmonton, AB T6G 2E1 (Canada); Ginsburg, Adam [European Southern Observatory, Karl-Schwarzschild-Straße 2, D-85748 Garching bei München (Germany); Evans II, Neal J. [Department of Astronomy, University of Texas, 2515 Speedway, Stop C1400, Austin, TX 78712 (United States); Battersby, Cara [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Shirley, Yancy L.; Svoboda, Brian, E-mail: timothy.ellsworthbowers@colorado.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2015-01-20

    We present an expanded distance catalog for 1710 molecular cloud structures identified in the Bolocam Galactic Plane Survey (BGPS) version 2, representing a nearly threefold increase over the previous BGPS distance catalog. We additionally present a new method for incorporating extant data sets into our Bayesian distance probability density function (DPDF) methodology. To augment the dense-gas tracers (e.g., HCO{sup +}(3-2), NH{sub 3}(1,1)) used to derive line-of-sight velocities for kinematic distances, we utilize the Galactic Ring Survey (GRS) {sup 13}CO(1-0) data to morphologically extract velocities for BGPS sources. The outline of a BGPS source is used to select a region of the GRS {sup 13}CO data, along with a reference region to subtract enveloping diffuse emission, to produce a line profile of {sup 13}CO matched to the BGPS source. For objects with a HCO{sup +}(3-2) velocity, ≈95% of the new {sup 13}CO(1-0) velocities agree with that of the dense gas. A new prior DPDF for kinematic distance ambiguity (KDA) resolution, based on a validated formalism for associating molecular cloud structures with known objects from the literature, is presented. We demonstrate this prior using catalogs of masers with trigonometric parallaxes and H II regions with robust KDA resolutions. The distance catalog presented here contains well-constrained distance estimates for 20% of BGPS V2 sources, with typical distance uncertainties ≲ 0.5 kpc. Approximately 75% of the well-constrained sources lie within 6 kpc of the Sun, concentrated in the Scutum-Centaurus arm. Galactocentric positions of objects additionally trace out portions of the Sagittarius, Perseus, and Outer arms in the first and second Galactic quadrants, and we also find evidence for significant regions of interarm dense gas.

  2. A Study of Faculty Attitudes toward Internet-Based Distance Education: A Survey of Two Jordanian Public Universities

    Science.gov (United States)

    Gasaymeh, Al-Mothana M.

    2009-01-01

    The purpose of this study was to examine the attitudes toward internet-based distance education by the faculty members of two Jordanian public universities, Al-Hussein Bin Talal University and Yarmouk University, as well as to explore the relationship between their attitudes toward internet-based distance education and their perceptions of their…

  3. Semi-automatic surface sediment sampling system - A prototype to be implemented in bivalve fishing surveys

    Science.gov (United States)

    Rufino, Marta M.; Baptista, Paulo; Pereira, Fábio; Gaspar, Miguel B.

    2018-01-01

    In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data, possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

  4. Improved sampling for airborne surveys to estimate wildlife population parameters in the African Savannah

    NARCIS (Netherlands)

    Khaemba, W.; Stein, A.

    2002-01-01

    Parameter estimates, obtained from airborne surveys of wildlife populations, often have large bias and large standard errors. Sampling error is one of the major causes of this imprecision and the occurrence of many animals in herds violates the common assumptions in traditional sampling designs like

  5. On the problems of PPS sampling in multi-character surveys ...

    African Journals Online (AJOL)

    This paper, which is on the problems of PPS sampling in multi-character surveys, compares the efficiency of some estimators used in PPSWR sampling for multiple characteristics. From a superpopulation model, we computed the expected variances of the different estimators for each of the first two finite populations ...

  6. [Study of spatial stratified sampling strategy of Oncomelania hupensis snail survey based on plant abundance].

    Science.gov (United States)

    Xun-Ping, W; An, Z

    2017-07-27

    Objective To optimize and simplify the survey method of Oncomelania hupensis snails in marshland endemic regions of schistosomiasis, so as to improve the precision, efficiency and economy of the snail survey. Methods A snail sampling strategy (Spatial Sampling Scenario of Oncomelania based on Plant Abundance, SOPA) which took the plant abundance as auxiliary variable was explored and an experimental study in a 50 m×50 m plot in a marshland in the Poyang Lake region was performed. Firstly, the push broom surveyed data was stratified into 5 layers by the plant abundance data; then, the required numbers of optimal sampling points of each layer through Hammond McCullagh equation were calculated; thirdly, every sample point in the line with the Multiple Directional Interpolation (MDI) placement scheme was pinpointed; and finally, the comparison study among the outcomes of the spatial random sampling strategy, the traditional systematic sampling method, the spatial stratified sampling method, Sandwich spatial sampling and inference and SOPA was performed. Results The method (SOPA) proposed in this study had the minimal absolute error of 0.213 8; and the traditional systematic sampling method had the largest estimate, and the absolute error was 0.924 4. Conclusion The snail sampling strategy (SOPA) proposed in this study obtains the higher estimation accuracy than the other four methods.

  7. Distance-regular graphs

    NARCIS (Netherlands)

    van Dam, Edwin R.; Koolen, Jack H.; Tanaka, Hajime

    2016-01-01

    This is a survey of distance-regular graphs. We present an introduction to distance-regular graphs for the reader who is unfamiliar with the subject, and then give an overview of some developments in the area of distance-regular graphs since the monograph 'BCN'[Brouwer, A.E., Cohen, A.M., Neumaier,

  8. THE DISTANCE TO M104

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W. [University of Texas at Austin, McDonald Observatory, 2515 Speedway, Stop C1400 Austin, TX 78712 (United States); Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, SE, University of Minnesota, Minneapolis, MN 55455 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Berg, Danielle [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Kennicutt, Robert, E-mail: kmcquinn@astro.as.utexas.edu [Institute for Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2016-11-01

    M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch (TRGB) method. Our measurement yields the distance to M104 to be 9.55 ± 0.13 ± 0.31 Mpc equivalent to a distance modulus of 29.90 ± 0.03 ± 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian maximum likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully–Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measure accurate distances to a sample of well-known spiral galaxies (including M51, M74, and M63) using the TRGB method.

  9. Direct comparison of observed magnitude-redshift relations in complete galaxy samples with systematic predictions of alternative redshift-distance laws

    International Nuclear Information System (INIS)

    Segal, I.E.

    1989-01-01

    The directly observed average apparent magnitude (or in one case, angular diameter) as a function of redshift in each of a number of large complete galaxy samples is compared with the predictions of hypothetical redshift-distance power laws, as a systematic statistical question. Due account is taken of observational flux limits by an entirely objective and reproducible optimal statistical procedure, and no assumptions are made regarding the distribution of the galaxies in space. The laws considered are of the form z varies as r p , where r denotes the distance, for p = 1, 2 and 3. The comparative fits of the various redshift-distance laws are similar in all the samples. Overall, the cubic law fits better than the linear law, but each shows substantial systematic deviations from observation. The quadratic law fits extremely well except at high redshifts in some of the samples, where no power law fits closely and the correlation of apparent magnitude with redshift is small or negative. In all cases, the luminosity function required for theoretical prediction was estimated from the sample by the non-parametric procedure ROBUST, whose intrinsic neutrality as programmed was checked by comprehensive computer simulations. (author)

  10. Sampling methods. A survey of methods in use in the Nordic countries

    International Nuclear Information System (INIS)

    Isaksson, M.

    2000-10-01

    This report is a survey of sampling techniques currently in use for radioactivity measurements in the Nordic countries, but restricted to sampling techniques for pasture, soil and deposition in emergency situations. It is found that the participating laboratories apply similar sampling procedures for pasture, including cutting height and size of sampled areas. Soil samples are generally taken by some sort of corer of different diameter. The number of cores taken varies, different sampling patterns are used, and pooling of the samples is done by some of the laboratories. The analysis of pasture and of soil is made with Nal-detectors or by high-resolution gamma spectrometry on fresh or dried samples. Precipitation collectors of a range of sizes are used to determine the activity concentration in precipitation and of dry deposited radionuclides. The analysis is made with high-resolution gamma-spectrometry, either directly on a water sample or on ion exchange resins. (au)

  11. Nationwide survey of policies and practices related to capillary blood sampling in medical laboratories in Croatia.

    Science.gov (United States)

    Krleza, Jasna Lenicek

    2014-01-01

    Capillary sampling is increasingly used to obtain blood for laboratory tests in volumes as small as necessary and as non-invasively as possible. Whether capillary blood sampling is also frequent in Croatia, and whether it is performed according to international laboratory standards is unclear. All medical laboratories that participate in the Croatian National External Quality Assessment Program (N = 204) were surveyed on-line to collect information about the laboratory's parent institution, patient population, types and frequencies of laboratory tests based on capillary blood samples, choice of reference intervals, and policies and procedures specifically related to capillary sampling. Sampling practices were compared with guidelines from the Clinical and Laboratory Standards Institute (CLSI) and the World Health Organization (WHO). Of the 204 laboratories surveyed, 174 (85%) responded with complete questionnaires. Among the 174 respondents, 155 (89%) reported that they routinely perform capillary sampling, which is carried out by laboratory staff in 118 laboratories (76%). Nearly half of respondent laboratories (48%) do not have a written protocol including order of draw for multiple sampling. A single puncture site is used to provide capillary blood for up to two samples at 43% of laboratories that occasionally or regularly perform such sampling. Most respondents (88%) never perform arterialisation prior to capillary blood sampling. Capillary blood sampling is highly prevalent in Croatia across different types of clinical facilities and patient populations. Capillary sampling procedures are not standardised in the country, and the rate of laboratory compliance with CLSI and WHO guidelines is low.

  12. Sampling guidelines for oral fluid-based surveys of group-housed animals.

    Science.gov (United States)

    Rotolo, Marisa L; Sun, Yaxuan; Wang, Chong; Giménez-Lirola, Luis; Baum, David H; Gauger, Phillip C; Harmon, Karen M; Hoogland, Marlin; Main, Rodger; Zimmerman, Jeffrey J

    2017-09-01

    Formulas and software for calculating sample size for surveys based on individual animal samples are readily available. However, sample size formulas are not available for oral fluids and other aggregate samples that are increasingly used in production settings. Therefore, the objective of this study was to develop sampling guidelines for oral fluid-based porcine reproductive and respiratory syndrome virus (PRRSV) surveys in commercial swine farms. Oral fluid samples were collected in 9 weekly samplings from all pens in 3 barns on one production site beginning shortly after placement of weaned pigs. Samples (n=972) were tested by real-time reverse-transcription PCR (RT-rtPCR) and the binary results analyzed using a piecewise exponential survival model for interval-censored, time-to-event data with misclassification. Thereafter, simulation studies were used to study the barn-level probability of PRRSV detection as a function of sample size, sample allocation (simple random sampling vs fixed spatial sampling), assay diagnostic sensitivity and specificity, and pen-level prevalence. These studies provided estimates of the probability of detection by sample size and within-barn prevalence. Detection using fixed spatial sampling was as good as, or better than, simple random sampling. Sampling multiple barns on a site increased the probability of detection with the number of barns sampled. These results are relevant to PRRSV control or elimination projects at the herd, regional, or national levels, but the results are also broadly applicable to contagious pathogens of swine for which oral fluid tests of equivalent performance are available. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Analyzing Repeated Measures Marginal Models on Sample Surveys with Resampling Methods

    Directory of Open Access Journals (Sweden)

    James D. Knoke

    2005-12-01

    Full Text Available Packaged statistical software for analyzing categorical, repeated measures marginal models on sample survey data with binary covariates does not appear to be available. Consequently, this report describes a customized SAS program which accomplishes such an analysis on survey data with jackknifed replicate weights for which the primary sampling unit information has been suppressed for respondent confidentiality. First, the program employs the Macro Language and the Output Delivery System (ODS to estimate the means and covariances of indicator variables for the response variables, taking the design into account. Then, it uses PROC CATMOD and ODS, ignoring the survey design, to obtain the design matrix and hypothesis test specifications. Finally, it enters these results into another run of CATMOD, which performs automated direct input of the survey design specifications and accomplishes the appropriate analysis. This customized SAS program can be employed, with minor editing, to analyze general categorical, repeated measures marginal models on sample surveys with replicate weights. Finally, the results of our analysis accounting for the survey design are compared to the results of two alternate analyses of the same data. This comparison confirms that such alternate analyses, which do not properly account for the design, do not produce useful results.

  14. Potential, velocity, and density fields from redshift-distance samples: Application - Cosmography within 6000 kilometers per second

    International Nuclear Information System (INIS)

    Bertschinger, E.; Dekel, A.; Faber, S.M.; Dressler, A.; Burstein, D.

    1990-01-01

    A potential flow reconstruction algorithm has been applied to the real universe to reconstruct the three-dimensional potential, velocity, and mass density fields smoothed on large scales. The results are shown as maps of these fields, revealing the three-dimensional structure within 6000 km/s distance from the Local Group. The dominant structure is an extended deep potential well in the Hydra-Centaurus region, stretching across the Galactic plane toward Pavo, broadly confirming the Great Attractor (GA) model of Lynden-Bell et al. (1988). The Local Supercluster appears to be an extended ridge on the near flank of the GA, proceeding through the Virgo Southern Extension to the Virgo and Ursa Major clusters. The Virgo cluster and the Local Group are both falling toward the bottom of the GA potential well with peculiar velocities of 658 + or - 121 km/s and 565 + or - 125 km/s, respectively. 65 refs

  15. Potential, velocity, and density fields from redshift-distance samples: Application - Cosmography within 6000 kilometers per second

    Science.gov (United States)

    Bertschinger, Edmund; Dekel, Avishai; Faber, Sandra M.; Dressler, Alan; Burstein, David

    1990-12-01

    A potential flow reconstruction algorithm has been applied to the real universe to reconstruct the three-dimensional potential, velocity, and mass density fields smoothed on large scales. The results are shown as maps of these fields, revealing the three-dimensional structure within 6000 km/s distance from the Local Group. The dominant structure is an extended deep potential well in the Hydra-Centaurus region, stretching across the Galactic plane toward Pavo, broadly confirming the Great Attractor (GA) model of Lynden-Bell et al. (1988). The Local Supercluster appears to be an extended ridge on the near flank of the GA, proceeding through the Virgo Southern Extension to the Virgo and Ursa Major clusters. The Virgo cluster and the Local Group are both falling toward the bottom of the GA potential well with peculiar velocities of 658 + or - 121 km/s and 565 + or - 125 km/s, respectively.

  16. Sampling strategy for a large scale indoor radiation survey - a pilot project

    International Nuclear Information System (INIS)

    Strand, T.; Stranden, E.

    1986-01-01

    Optimisation of a stratified random sampling strategy for large scale indoor radiation surveys is discussed. It is based on the results from a small scale pilot project where variances in dose rates within different categories of houses were assessed. By selecting a predetermined precision level for the mean dose rate in a given region, the number of measurements needed can be optimised. The results of a pilot project in Norway are presented together with the development of the final sampling strategy for a planned large scale survey. (author)

  17. Sample survey methods as a quality assurance tool in a general practice immunisation audit.

    Science.gov (United States)

    Cullen, R

    1994-04-27

    In a multidoctor family practice there are often just too many sets of patients records to make it practical to repeat an audit by census of even an age band of the practice on a regular basis. This paper attempts to demonstrate how sample survey methodology can be incorporated into the quality assurance cycle. A simple random sample (with replacement) of 120 from 580 children with permanent records who were aged between 6 weeks and 2 years old from an Auckland general practice was performed, with sample size selected to give a predetermined precision. The survey was then repeated after 4 weeks. Both surveys were able to be completed within the course of a normal working day. An unexpectedly low level of under 2 years olds that were recorded as not overdue for any immunisations was found (22.5%) with only a modest improvement after a standard telephone/letter catch up campaign. Seventy-two percent of the sample held a group one community services card. The advantages of properly conducted sample surveys in producing useful estimates of known precision without disrupting office routines excessively were demonstrated. Through some attention to methodology, the trauma of a practice census can be avoided.

  18. An assessment of Lot Quality Assurance Sampling to evaluate malaria outcome indicators: extending malaria indicator surveys.

    Science.gov (United States)

    Biedron, Caitlin; Pagano, Marcello; Hedt, Bethany L; Kilian, Albert; Ratcliffe, Amy; Mabunda, Samuel; Valadez, Joseph J

    2010-02-01

    Large investments and increased global prioritization of malaria prevention and treatment have resulted in greater emphasis on programme monitoring and evaluation (M&E) in many countries. Many countries currently use large multistage cluster sample surveys to monitor malaria outcome indicators on a regional and national level. However, these surveys often mask local-level variability important to programme management. Lot Quality Assurance Sampling (LQAS) has played a valuable role for local-level programme M&E. If incorporated into these larger surveys, it would provide a comprehensive M&E plan at little, if any, extra cost. The Mozambique Ministry of Health conducted a Malaria Indicator Survey (MIS) in June and July 2007. We applied LQAS classification rules to the 345 sampled enumeration areas to demonstrate identifying high- and low-performing areas with respect to two malaria program indicators-'household possession of any bednet' and 'household possession of any insecticide-treated bednet (ITN)'. As shown by the MIS, no province in Mozambique achieved the 70% coverage target for household possession of bednets or ITNs. By applying LQAS classification rules to the data, we identify 266 of the 345 enumeration areas as having bednet coverage severely below the 70% target. An additional 73 were identified with low ITN coverage. This article demonstrates the feasibility of integrating LQAS into multistage cluster sampling surveys and using these results to support a comprehensive national, regional and local programme M&E system. Furthermore, in the recommendations we outlined how to integrate the Large Country-LQAS design into macro-surveys while still obtaining results available through current sampling practices.

  19. Nationwide survey of policies and practices related to capillary blood sampling in medical laboratories in Croatia

    OpenAIRE

    Lenicek Krleza, Jasna

    2014-01-01

    Introduction: Capillary sampling is increasingly used to obtain blood for laboratory tests in volumes as small as necessary and as non-invasively as possible. Whether capillary blood sampling is also frequent in Croatia, and whether it is performed according to international laboratory standards is unclear. Materials and methods: All medical laboratories that participate in the Croatian National External Quality Assessment Program (N = 204) were surveyed on-line to collect information about t...

  20. Analysis and radiological assessment of survey results and samples from the beaches around Sellafield

    International Nuclear Information System (INIS)

    Webb, G.A.M.; Fry, F.A.

    1983-12-01

    After radioactive sea debris had been found on beaches near the BNFL, Sellafield, plant, NRPB was asked by the Department of the Environment to analyse some of the samples collected and to assess the radiological hazard to members of the public. A report is presented containing an analysis of survey reports for the period 19 November - 4 December 1983 and preliminary results of the analysis of all samples received, together with the Board's recommendations. (author)

  1. Trypanosoma brucei gambiense trypanosomiasis in Terego county, northern Uganda, 1996: a lot quality assurance sampling survey.

    Science.gov (United States)

    Hutin, Yvan J F; Legros, Dominique; Owini, Vincent; Brown, Vincent; Lee, Evan; Mbulamberi, Dawson; Paquet, Christophe

    2004-04-01

    We estimated the pre-intervention prevalence of Trypanosoma brucei gambiense (Tbg) trypanosomiasis using the lot quality assurance sampling (LQAS) methods in 14 parishes of Terego County in northern Uganda. A total of 826 participants were included in the survey sample in 1996. The prevalence of laboratory confirmed Tbg trypanosomiasis adjusted for parish population sizes was 2.2% (95% confidence interval =1.1-3.2). This estimate was consistent with the 1.1% period prevalence calculated on the basis of cases identified through passive and active screening in 1996-1999. Ranking of parishes in four categories according to LQAS analysis of the 1996 survey predicted the prevalences observed during the first round of active screening in the population in 1997-1998 (P LQAS were validated by the results of the population screening, suggesting that these survey methods may be useful in the pre-intervention phase of sleeping sickness control programs.

  2. A Nationwide Random Sampling Survey of Potential Complicated Grief in Japan

    Science.gov (United States)

    Mizuno, Yasunao; Kishimoto, Junji; Asukai, Nozomu

    2012-01-01

    To investigate the prevalence of significant loss, potential complicated grief (CG), and its contributing factors, we conducted a nationwide random sampling survey of Japanese adults aged 18 or older (N = 1,343) using a self-rating Japanese-language version of the Complicated Grief Brief Screen. Among them, 37.0% experienced their most significant…

  3. Conducting a respondent-driven sampling survey with the use of existing resources in Sydney, Australia.

    Science.gov (United States)

    Paquette, Dana M; Bryant, Joanne; Crawford, Sione; de Wit, John B F

    2011-07-01

    Respondent-driven sampling (RDS) is a form of chain-referral sampling that is increasingly being used for HIV behavioural surveillance. When used for surveillance purposes, a sampling method should be relatively inexpensive and simple to operate. This study examined whether an RDS survey of people who inject drugs (PWID) in Sydney, Australia, could be successfully conducted through the use of minimal and existing resources. The RDS survey was conducted on the premises of a local needle and syringe program (NSP) with some adjustments to take into account the constraints of existing resources. The impact of the survey on clients and on staff was examined by summarizing NSP service data and by conducting post-survey discussions with NSP staff. From November 2009 till March 2010, 261 participants were recruited in 16 waves. A significant increase was found in the number of services provided by the NSP during and after data collection. Generally, staff felt that the survey had a positive impact by exposing a broader group of people to the NSP. However, conducting the survey may have led to privacy issues for NSP clients due to an increased number of people gathering around the NSP. This study shows that RDS can be conducted with the use of minimal and existing resources under certain conditions (e.g., use of a self-administered questionnaire and no biological samples taken). A more detailed cost-utility analysis is needed to determine whether RDS' advantages outweigh potential challenges when compared to simpler and less costly convenience methods. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Implementation of Web- Based Distance Education in Nursing Education in Turkey: A Sample Lesson in Patient Education

    Science.gov (United States)

    Senyuva, Emine; Tasocak, Gülsün

    2014-01-01

    The research was carried out in 2005-2006 as a descriptive and methodological study. It aimed to obtain students' feedback and to serve as a source for future relevant studies. The setting of the study was Istanbul University Florence Nightingale Nursing College and at Istanbul University Bakirköy Health College. The sample of the study included…

  5. Seasonal associations and atmospheric transport distances of fungi in the genus Fusarium collected with unmanned aerial vehicles and ground-based sampling devices

    Science.gov (United States)

    Lin, Binbin; Ross, Shane D.; Prussin, Aaron J.; Schmale, David G.

    2014-09-01

    Spores of fungi in the genus Fusarium may be transported through the atmosphere over long distances. New information is needed to characterize seasonal trends in atmospheric loads of Fusarium and to pinpoint the source(s) of inoculum at both local (farm) and regional (state or country) scales. We hypothesized that (1) atmospheric concentrations of Fusarium spores in an agricultural ecosystem vary with height and season and (2) transport distances from potential inoculum source(s) vary with season. To test these hypotheses, spores of Fusarium were collected from the atmosphere in an agricultural ecosystem in Blacksburg, VA, USA using a Burkard volumetric sampler (BVS) 1 m above ground level and autonomous unmanned aerial vehicles (UAVs) 100 m above ground level. More than 2200 colony forming units (CFUs) of Fusarium were collected during 104 BVS sampling periods and 180 UAV sampling periods over four calendar years (2009-2012). Spore concentrations ranged from 0 to 13 and 0 to 23 spores m-3 for the BVS and the UAVs, respectively. Spore concentrations were generally higher in the fall, spring, and summer, and lower in the winter. Spore concentrations from the BVS were generally higher than those from the UAVs for both seasonal and hourly collections. A Gaussian plume transport model was used to estimate distances to the potential inoculum source(s) by season, and produced mean transport distances of 1.4 km for the spring, 1.7 km for the summer, 1.2 km for the fall, and 4.1 km for the winter. Environmental signatures that predict atmospheric loads of Fusarium could inform disease spread, air pollution, and climate change.

  6. The economic impact of poor sample quality in clinical chemistry laboratories: results from a global survey.

    Science.gov (United States)

    Erdal, Erik P; Mitra, Debanjali; Khangulov, Victor S; Church, Stephen; Plokhoy, Elizabeth

    2017-03-01

    Background Despite advances in clinical chemistry testing, poor blood sample quality continues to impact laboratory operations and the quality of results. While previous studies have identified the preanalytical causes of lower sample quality, few studies have examined the economic impact of poor sample quality on the laboratory. Specifically, the costs associated with workarounds related to fibrin and gel contaminants remain largely unexplored. Methods A quantitative survey of clinical chemistry laboratory stakeholders across 10 international regions, including countries in North America, Europe and Oceania, was conducted to examine current blood sample testing practices, sample quality issues and practices to remediate poor sample quality. Survey data were used to estimate costs incurred by laboratories to mitigate sample quality issues. Results Responses from 164 participants were included in the analysis, which was focused on three specific issues: fibrin strands, fibrin masses and gel globules. Fibrin strands were the most commonly reported issue, with an overall incidence rate of ∼3%. Further, 65% of respondents indicated that these issues contribute to analyzer probe clogging, and the majority of laboratories had visual inspection and manual remediation practices in place to address fibrin- and gel-related quality problems (55% and 70%, respectively). Probe maintenance/replacement, visual inspection and manual remediation were estimated to carry significant costs for the laboratories surveyed. Annual cost associated with lower sample quality and remediation related to fibrin and/or gel globules for an average US laboratory was estimated to be $100,247. Conclusions Measures to improve blood sample quality present an important step towards improved laboratory operations.

  7. Survey of sampling-based methods for uncertainty and sensitivity analysis

    International Nuclear Information System (INIS)

    Helton, J.C.; Johnson, J.D.; Sallaberry, C.J.; Storlie, C.B.

    2006-01-01

    Sampling-based methods for uncertainty and sensitivity analysis are reviewed. The following topics are considered: (i) definition of probability distributions to characterize epistemic uncertainty in analysis inputs (ii) generation of samples from uncertain analysis inputs (iii) propagation of sampled inputs through an analysis (iv) presentation of uncertainty analysis results, and (v) determination of sensitivity analysis results. Special attention is given to the determination of sensitivity analysis results, with brief descriptions and illustrations given for the following procedures/techniques: examination of scatterplots, correlation analysis, regression analysis, partial correlation analysis, rank transformations, statistical tests for patterns based on gridding, entropy tests for patterns based on gridding, nonparametric regression analysis, squared rank differences/rank correlation coefficient test, two-dimensional Kolmogorov-Smirnov test, tests for patterns based on distance measures, top down coefficient of concordance, and variance decomposition

  8. Survey of sampling-based methods for uncertainty and sensitivity analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean; Helton, Jon Craig; Sallaberry, Cedric J. PhD. (.; .); Storlie, Curt B. (Colorado State University, Fort Collins, CO)

    2006-06-01

    Sampling-based methods for uncertainty and sensitivity analysis are reviewed. The following topics are considered: (1) Definition of probability distributions to characterize epistemic uncertainty in analysis inputs, (2) Generation of samples from uncertain analysis inputs, (3) Propagation of sampled inputs through an analysis, (4) Presentation of uncertainty analysis results, and (5) Determination of sensitivity analysis results. Special attention is given to the determination of sensitivity analysis results, with brief descriptions and illustrations given for the following procedures/techniques: examination of scatterplots, correlation analysis, regression analysis, partial correlation analysis, rank transformations, statistical tests for patterns based on gridding, entropy tests for patterns based on gridding, nonparametric regression analysis, squared rank differences/rank correlation coefficient test, two dimensional Kolmogorov-Smirnov test, tests for patterns based on distance measures, top down coefficient of concordance, and variance decomposition.

  9. Nationwide survey of policies and practices related to capillary blood sampling in medical laboratories in Croatia

    Science.gov (United States)

    Krleza, Jasna Lenicek

    2014-01-01

    Introduction: Capillary sampling is increasingly used to obtain blood for laboratory tests in volumes as small as necessary and as non-invasively as possible. Whether capillary blood sampling is also frequent in Croatia, and whether it is performed according to international laboratory standards is unclear. Materials and methods: All medical laboratories that participate in the Croatian National External Quality Assessment Program (N = 204) were surveyed on-line to collect information about the laboratory’s parent institution, patient population, types and frequencies of laboratory tests based on capillary blood samples, choice of reference intervals, and policies and procedures specifically related to capillary sampling. Sampling practices were compared with guidelines from the Clinical and Laboratory Standards Institute (CLSI) and the World Health Organization (WHO). Results: Of the 204 laboratories surveyed, 174 (85%) responded with complete questionnaires. Among the 174 respondents, 155 (89%) reported that they routinely perform capillary sampling, which is carried out by laboratory staff in 118 laboratories (76%). Nearly half of respondent laboratories (48%) do not have a written protocol including order of draw for multiple sampling. A single puncture site is used to provide capillary blood for up to two samples at 43% of laboratories that occasionally or regularly perform such sampling. Most respondents (88%) never perform arterialisation prior to capillary blood sampling. Conclusions: Capillary blood sampling is highly prevalent in Croatia across different types of clinical facilities and patient populations. Capillary sampling procedures are not standardised in the country, and the rate of laboratory compliance with CLSI and WHO guidelines is low. PMID:25351353

  10. Infall and outflow motions towards a sample of massive star-forming regions from the RMS survey

    Science.gov (United States)

    Cunningham, N.; Lumsden, S. L.; Moore, T. J. T.; Maud, L. T.; Mendigutía, I.

    2018-06-01

    We present the results of an outflow and infall survey towards a distance-limited sample of 31 massive star-forming regions drawn from the Red MSX source (RMS) survey. The presence of young, active outflows is identified from SiO (8-7) emission and the infall dynamics are explored using HCO+/H13CO+ (4-3) emission. We investigate if the infall and outflow parameters vary with source properties, exploring whether regions hosting potentially young active outflows show similarities or differences with regions harbouring more evolved, possibly momentum-driven, `fossil' outflows. SiO emission is detected towards approximately 46 per cent of the sources. When considering sources with and without an SiO detection (i.e. potentially active and fossil outflows, respectively), only the 12CO outflow velocity shows a significant difference between samples, indicating SiO is more prevalent towards sources with higher outflow velocities. Furthermore, we find the SiO luminosity increases as a function of the Herschel 70 μm to WISE 22 μm flux ratio, suggesting the production of SiO is prevalent in younger, more embedded regions. Similarly, we find tentative evidence that sources with an SiO detection have a smaller bolometric luminosity-to-mass ratio, indicating SiO (8-7) emission is associated with potentially younger regions. We do not find a prevalence towards sources displaying signatures of infall in our sample. However, the higher energy HCO+ transitions may not be the best suited tracer of infall at this spatial resolution in these regions.

  11. The effect of Medicaid adult vision coverage on the likelihood of appropriate correction of distance vision: Evidence from the National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Lipton, Brandy J; Decker, Sandra L

    2016-02-01

    Medicaid is the main public health insurance program for individuals with low income in the United States. Some state Medicaid programs cover preventive eye care services and vision correction, while others cover emergency eye care only. Similar to other optional benefits, states may add and drop adult vision benefits over time. This article examines whether providing adult vision benefits is associated with an increase in the percentage of low-income individuals with appropriately corrected distance vision as measured during an eye exam. We estimate the effect of Medicaid vision coverage on the likelihood of having appropriately corrected distance vision using examination data from the 2001-2008 National Health and Nutrition Examination Survey. We compare vision outcomes for Medicaid beneficiaries (n = 712) and other low income adults not enrolled in Medicaid (n = 4786) before and after changes to state vision coverage policies. Between 29 and 33 states provided Medicaid adult vision benefits during 2001-2008, depending on the year. Our findings imply that Medicaid adult vision coverage is associated with a significant increase in the percentage of Medicaid beneficiaries with appropriately corrected distance vision of up to 10 percentage points. Providing vision coverage to adults on Medicaid significantly increases the likelihood of appropriate correction of distance vision. Further research on the impact of vision coverage on related functional outcomes and the effects of Medicaid coverage of other services may be appropriate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. CT dose survey in adults: what sample size for what precision?

    International Nuclear Information System (INIS)

    Taylor, Stephen; Muylem, Alain van; Howarth, Nigel; Gevenois, Pierre Alain; Tack, Denis

    2017-01-01

    To determine variability of volume computed tomographic dose index (CTDIvol) and dose-length product (DLP) data, and propose a minimum sample size to achieve an expected precision. CTDIvol and DLP values of 19,875 consecutive CT acquisitions of abdomen (7268), thorax (3805), lumbar spine (3161), cervical spine (1515) and head (4106) were collected in two centers. Their variabilities were investigated according to sample size (10 to 1000 acquisitions) and patient body weight categories (no weight selection, 67-73 kg and 60-80 kg). The 95 % confidence interval in percentage of their median (CI95/med) value was calculated for increasing sample sizes. We deduced the sample size that set a 95 % CI lower than 10 % of the median (CI95/med ≤ 10 %). Sample size ensuring CI95/med ≤ 10 %, ranged from 15 to 900 depending on the body region and the dose descriptor considered. In sample sizes recommended by regulatory authorities (i.e., from 10-20 patients), mean CTDIvol and DLP of one sample ranged from 0.50 to 2.00 times its actual value extracted from 2000 samples. The sampling error in CTDIvol and DLP means is high in dose surveys based on small samples of patients. Sample size should be increased at least tenfold to decrease this variability. (orig.)

  13. CT dose survey in adults: what sample size for what precision?

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Stephen [Hopital Ambroise Pare, Department of Radiology, Mons (Belgium); Muylem, Alain van [Hopital Erasme, Department of Pneumology, Brussels (Belgium); Howarth, Nigel [Clinique des Grangettes, Department of Radiology, Chene-Bougeries (Switzerland); Gevenois, Pierre Alain [Hopital Erasme, Department of Radiology, Brussels (Belgium); Tack, Denis [EpiCURA, Clinique Louis Caty, Department of Radiology, Baudour (Belgium)

    2017-01-15

    To determine variability of volume computed tomographic dose index (CTDIvol) and dose-length product (DLP) data, and propose a minimum sample size to achieve an expected precision. CTDIvol and DLP values of 19,875 consecutive CT acquisitions of abdomen (7268), thorax (3805), lumbar spine (3161), cervical spine (1515) and head (4106) were collected in two centers. Their variabilities were investigated according to sample size (10 to 1000 acquisitions) and patient body weight categories (no weight selection, 67-73 kg and 60-80 kg). The 95 % confidence interval in percentage of their median (CI95/med) value was calculated for increasing sample sizes. We deduced the sample size that set a 95 % CI lower than 10 % of the median (CI95/med ≤ 10 %). Sample size ensuring CI95/med ≤ 10 %, ranged from 15 to 900 depending on the body region and the dose descriptor considered. In sample sizes recommended by regulatory authorities (i.e., from 10-20 patients), mean CTDIvol and DLP of one sample ranged from 0.50 to 2.00 times its actual value extracted from 2000 samples. The sampling error in CTDIvol and DLP means is high in dose surveys based on small samples of patients. Sample size should be increased at least tenfold to decrease this variability. (orig.)

  14. Distance Learning

    National Research Council Canada - National Science Library

    Braddock, Joseph

    1997-01-01

    A study reviewing the existing Army Distance Learning Plan (ADLP) and current Distance Learning practices, with a focus on the Army's training and educational challenges and the benefits of applying Distance Learning techniques...

  15. Spread of Traditional Medicines in India: Results of National Sample Survey Organization's Perception Survey on Use of AYUSH.

    Science.gov (United States)

    Srinivasan, R; Sugumar, V Raji

    2015-10-04

    For the first time, we have a comprehensive database on usage of AYUSH (acronym for Ayurveda, naturopathy and Yoga, Unani, Siddha, and Homeopathy) in India at the household level. This article aims at exploring the spread of the traditional medical systems in India and the perceptions of people on the access and effectiveness of these medical systems using this database. The article uses the unit level data purchased from the National Sample Survey Organization, New Delhi. Household is the basic unit of survey and the data are the collective opinion of the household. This survey shows that less than 30% of Indian households use the traditional medical systems. There is also a regional pattern in the usage of particular type of traditional medicine, reflecting the regional aspects of the development of such medical systems. The strong faith in AYUSH is the main reason for its usage; lack of need for AYUSH and lack of awareness about AYUSH are the main reasons for not using it. With regard to source of medicines in the traditional medical systems, home is the main source in the Indian medical system and private sector is the main source in Homeopathy. This shows that there is need for creating awareness and improving access to traditional medical systems in India. By and large, the users of AYUSH are also convinced about the effectiveness of these traditional medicines. © The Author(s) 2015.

  16. Sample size methods for estimating HIV incidence from cross-sectional surveys.

    Science.gov (United States)

    Konikoff, Jacob; Brookmeyer, Ron

    2015-12-01

    Understanding HIV incidence, the rate at which new infections occur in populations, is critical for tracking and surveillance of the epidemic. In this article, we derive methods for determining sample sizes for cross-sectional surveys to estimate incidence with sufficient precision. We further show how to specify sample sizes for two successive cross-sectional surveys to detect changes in incidence with adequate power. In these surveys biomarkers such as CD4 cell count, viral load, and recently developed serological assays are used to determine which individuals are in an early disease stage of infection. The total number of individuals in this stage, divided by the number of people who are uninfected, is used to approximate the incidence rate. Our methods account for uncertainty in the durations of time spent in the biomarker defined early disease stage. We find that failure to account for this uncertainty when designing surveys can lead to imprecise estimates of incidence and underpowered studies. We evaluated our sample size methods in simulations and found that they performed well in a variety of underlying epidemics. Code for implementing our methods in R is available with this article at the Biometrics website on Wiley Online Library. © 2015, The International Biometric Society.

  17. Extinctions and Distances to Dark Clouds from 2MASS, MegaCam and IPHAS Surveys: LDN 1525 in the Direction of the Aur OB1 Association

    Directory of Open Access Journals (Sweden)

    Straižys V.

    2010-12-01

    Full Text Available The possibility of applying photometry from the 2MASS J, H, Ks, MegaCam u, g and IPHAS r, i, Hα surveys for determining the distance to the dark cloud LDN1525 (TGU 1192 in the direction of the Aur OB1 association is investigated using the red clump giants. The main dust cloud, probably related to the emission nebulae Sh 2-232, Sh 2-233, Sh 2-235, the molecular cloud and the association Aur OB2, is found to be located at a distance of 1.3 kpc from the Sun. The nebula Sh 2-231 can be an object of the Perseus arm. The maximum extinction AV found in the cloud is close to 6 mag.

  18. The ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES) . I. Project description, survey sample, and quality assessment

    Science.gov (United States)

    Cox, Nick L. J.; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J.; Marshall, Charlotte C. M.; Smith, Keith T.; Evans, Christopher J.; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A.; Joblin, Christine; van Loon, Jacco Th.; Foing, Bernard H.; Bhatt, Neil H.; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G.; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

    2017-10-01

    The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C60^+ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort tosystematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral-type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R 70 000-100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.

  19. Innovate the Teaching of Taiwaness History: An Application of Multimedia Distance Learning—A Web-site Construction Sample of Shih Hsin University

    Directory of Open Access Journals (Sweden)

    Shaw-Fong Lee

    2004-03-01

    Full Text Available Traditionally, the teaching of history course mostly utilizes face to face instruction and oral presentation. Along with the development of educational technology, the teaching methods could be more various such as using internet and multimedia. Literature reviews also indicate that using internet and multimedia may improve the effect of learning and teaching. This paper explores the development of a web-based instructional system for the course of Taiwanese History at Shih Hsin University.The result and the product of this development project is the web site, http://distance.shu.edu.tw/taiwan/list.htm. The content of the web-site includes instructional materials such as animations, videos, pictures, texts, historical maps, and so on. The developmental methods used in this project use curriculum design, survey, interview, review of literatures and focus group discussion.[Article content in Chinese

  20. Creel survey sampling designs for estimating effort in short-duration Chinook salmon fisheries

    Science.gov (United States)

    McCormick, Joshua L.; Quist, Michael C.; Schill, Daniel J.

    2013-01-01

    Chinook Salmon Oncorhynchus tshawytscha sport fisheries in the Columbia River basin are commonly monitored using roving creel survey designs and require precise, unbiased catch estimates. The objective of this study was to examine the relative bias and precision of total catch estimates using various sampling designs to estimate angling effort under the assumption that mean catch rate was known. We obtained information on angling populations based on direct visual observations of portions of Chinook Salmon fisheries in three Idaho river systems over a 23-d period. Based on the angling population, Monte Carlo simulations were used to evaluate the properties of effort and catch estimates for each sampling design. All sampling designs evaluated were relatively unbiased. Systematic random sampling (SYS) resulted in the most precise estimates. The SYS and simple random sampling designs had mean square error (MSE) estimates that were generally half of those observed with cluster sampling designs. The SYS design was more efficient (i.e., higher accuracy per unit cost) than a two-cluster design. Increasing the number of clusters available for sampling within a day decreased the MSE of estimates of daily angling effort, but the MSE of total catch estimates was variable depending on the fishery. The results of our simulations provide guidelines on the relative influence of sample sizes and sampling designs on parameters of interest in short-duration Chinook Salmon fisheries.

  1. Sampling effects on the identification of roadkill hotspots: Implications for survey design.

    Science.gov (United States)

    Santos, Sara M; Marques, J Tiago; Lourenço, André; Medinas, Denis; Barbosa, A Márcia; Beja, Pedro; Mira, António

    2015-10-01

    Although locating wildlife roadkill hotspots is essential to mitigate road impacts, the influence of study design on hotspot identification remains uncertain. We evaluated how sampling frequency affects the accuracy of hotspot identification, using a dataset of vertebrate roadkills (n = 4427) recorded over a year of daily surveys along 37 km of roads. "True" hotspots were identified using this baseline dataset, as the 500-m segments where the number of road-killed vertebrates exceeded the upper 95% confidence limit of the mean, assuming a Poisson distribution of road-kills per segment. "Estimated" hotspots were identified likewise, using datasets representing progressively lower sampling frequencies, which were produced by extracting data from the baseline dataset at appropriate time intervals (1-30 days). Overall, 24.3% of segments were "true" hotspots, concentrating 40.4% of roadkills. For different groups, "true" hotspots accounted from 6.8% (bats) to 29.7% (small birds) of road segments, concentrating from 60% (lizards, lagomorphs, carnivores) of roadkills. Spatial congruence between "true" and "estimated" hotspots declined rapidly with increasing time interval between surveys, due primarily to increasing false negatives (i.e., missing "true" hotspots). There were also false positives (i.e., wrong "estimated" hotspots), particularly at low sampling frequencies. Spatial accuracy decay with increasing time interval between surveys was higher for smaller-bodied (amphibians, reptiles, small birds, small mammals) than for larger-bodied species (birds of prey, hedgehogs, lagomorphs, carnivores). Results suggest that widely used surveys at weekly or longer intervals may produce poor estimates of roadkill hotspots, particularly for small-bodied species. Surveying daily or at two-day intervals may be required to achieve high accuracy in hotspot identification for multiple species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Prevalence of dementia-associated disability among Chinese older adults: results from a national sample survey.

    Science.gov (United States)

    Li, Ning; Zhang, Lei; Du, Wei; Pang, Lihua; Guo, Chao; Chen, Gong; Zheng, Xiaoying

    2015-03-01

    Due to rapid population aging and a tidal wave of dementia, dementia has become an urgent public health issue in China. Few large-scale surveys on dementia have been conducted in China and little was known about the magnitude of dysfunction and disability caused by dementia. In this study, using national sample survey data, we aimed to describe the prevalence rate of dementia-associated disability, its associated factors, and daily activities and social functions of people with dementia-associated disability in Chinese older adults. We used the second China National Sample Survey on Disability, comprising 2,526,145 persons from 771,797 households. Identification for dementia was based on consensus manuals. Standard weighting procedures were used to construct sample weights considering the multistage stratified cluster sampling survey scheme. Population weighted numbers, weighted prevalence, and the odd ratios (ORs) were calculated. The prevalence rate of dementia-associated disability was 4.64% (95% CI: 4.26-5.01) and it accounted for 41.03% of mental disability among Chinese older adults. Urban residence (OR: 1.33 [1.12-1.57]), older age (80+ years) (OR: 4.12 [3.38-.03]), illiteracy (OR: 1.79 [1.27-2.53]), and currently not married (OR: 1.15 [1.00-1.32]) were associated with increased risk of dementia-associated disability. Compared with those with mental disability of other causes and those with other types of disabilities, older adults with dementia-asscoiated disability were more likely to have severe or extreme difficulty in daily activities and social functions. Countermeasures are warranted to obtain a more precise overview of dementia in China, and strategies on enhancing early identification, treatment, and rehabilitation should be developed for people with dementia. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  3. Like a virgin (mother): analysis of data from a longitudinal, US population representative sample survey

    OpenAIRE

    Herring, Amy H; Attard, Samantha M; Gordon-Larsen, Penny; Joyner, William H; Halpern, Carolyn T

    2013-01-01

    Objective To estimate the incidence of self report of pregnancy without sexual intercourse (virgin pregnancy) and factors related to such reporting, in a population representative group of US adolescents and young adults. Design Longitudinal, population representative sample survey. Setting Nationally representative, multiethnic National Longitudinal Study of Adolescent Health, United States. Participants 7870 women enrolled at wave I (1995) and completing the most recent wave of data collect...

  4. Principal components in the discrimination of outliers: A study in simulation sample data corrected by Pearson's and Yates´s chi-square distance

    Directory of Open Access Journals (Sweden)

    Manoel Vitor de Souza Veloso

    2016-04-01

    Full Text Available Current study employs Monte Carlo simulation in the building of a significance test to indicate the principal components that best discriminate against outliers. Different sample sizes were generated by multivariate normal distribution with different numbers of variables and correlation structures. Corrections by chi-square distance of Pearson´s and Yates's were provided for each sample size. Pearson´s correlation test showed the best performance. By increasing the number of variables, significance probabilities in favor of hypothesis H0 were reduced. So that the proposed method could be illustrated, a multivariate time series was applied with regard to sales volume rates in the state of Minas Gerais, obtained in different market segments.

  5. Barriers to Distance Education in Rural Schools

    Science.gov (United States)

    Irvin, Matthew J.; Hannum, Wallace H.; Varre, Claire de la; Farmer, Thomas W.

    2010-01-01

    The primary purpose of the current study was to examine barriers to the use of distance education and explore related factors in small and low-income rural schools. Data were collected via a telephone survey with administrators or other qualified personnel. The sample involved 417 randomly selected small and low-income rural school districts…

  6. Comparing two survey methods of measuring health-related indicators: Lot Quality Assurance Sampling and Demographic Health Surveys.

    Science.gov (United States)

    Anoke, Sarah C; Mwai, Paul; Jeffery, Caroline; Valadez, Joseph J; Pagano, Marcello

    2015-12-01

    Two common methods used to measure indicators for health programme monitoring and evaluation are the demographic and health surveys (DHS) and lot quality assurance sampling (LQAS); each one has different strengths. We report on both methods when utilised in comparable situations. We compared 24 indicators in south-west Uganda, where data for prevalence estimations were collected independently for the two methods in 2011 (LQAS: n = 8876; DHS: n = 1200). Data were stratified (e.g. gender and age) resulting in 37 comparisons. We used a two-sample two-sided Z-test of proportions to compare both methods. The average difference between LQAS and DHS for 37 estimates was 0.062 (SD = 0.093; median = 0.039). The average difference among the 21 failures to reject equality of proportions was 0.010 (SD = 0.041; median = 0.009); among the 16 rejections, it was 0.130 (SD = 0.010, median = 0.118). Seven of the 16 rejections exhibited absolute differences of 0.10 and 0.20 (mean = 0.261, SD = 0.083). There is 75.7% agreement across the two surveys. Both methods yield regional results, but only LQAS provides information at less granular levels (e.g. the district level) where managerial action is taken. The cost advantage and localisation make LQAS feasible to conduct more frequently, and provides the possibility for real-time health outcomes monitoring. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  7. Dealing with trade-offs in destructive sampling designs for occupancy surveys.

    Directory of Open Access Journals (Sweden)

    Stefano Canessa

    Full Text Available Occupancy surveys should be designed to minimise false absences. This is commonly achieved by increasing replication or increasing the efficiency of surveys. In the case of destructive sampling designs, in which searches of individual microhabitats represent the repeat surveys, minimising false absences leads to an inherent trade-off. Surveyors can sample more low quality microhabitats, bearing the resultant financial costs and producing wider-spread impacts, or they can target high quality microhabitats were the focal species is more likely to be found and risk more severe impacts on local habitat quality. We show how this trade-off can be solved with a decision-theoretic approach, using the Millewa Skink Hemiergis millewae from southern Australia as a case study. Hemiergis millewae is an endangered reptile that is best detected using destructive sampling of grass hummocks. Within sites that were known to be occupied by H. millewae, logistic regression modelling revealed that lizards were more frequently detected in large hummocks. If this model is an accurate representation of the detection process, searching large hummocks is more efficient and requires less replication, but this strategy also entails destruction of the best microhabitats for the species. We developed an optimisation tool to calculate the minimum combination of the number and size of hummocks to search to achieve a given cumulative probability of detecting the species at a site, incorporating weights to reflect the sensitivity of the results to a surveyor's priorities. The optimisation showed that placing high weight on minimising volume necessitates impractical replication, whereas placing high weight on minimising replication requires searching very large hummocks which are less common and may be vital for H. millewae. While destructive sampling methods are sometimes necessary, surveyors must be conscious of the ecological impacts of these methods. This study provides a

  8. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey. I. Sample Selection and Redshift Distribution

    Science.gov (United States)

    Perley, D. A.; Kruhler, T.; Schulze, S.; Postigo, A. De Ugarte; Hjorth, J.; Berger, E.; Cenko, S. B.; Chary, R.; Cucchiara, A.; Ellis, R.; hide

    2016-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey (SHOALS), a multi-observatory high redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst (GRB) hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host galaxy observational program, consisting of deep Spitzer/IRAC imaging of every field supplemented by similarly deep, multicolor optical/near-IR photometry, plus spectroscopy of events without preexisting redshifts. Our optimized selection cuts combined with host galaxy follow-up have so far enabled redshift measurements for 110 targets (92%) and placed upper limits on all but one of the remainder. About 20% of GRBs in the sample are heavily dust obscured, and at most 2% originate from z > 5.5. Using this sample, we estimate the redshift-dependent GRB rate density, showing it to peak at z approx. 2.5 and fall by at least an order of magnitude toward low (z = 0) redshift, while declining more gradually toward high (z approx. 7) redshift. This behavior is consistent with a progenitor whose formation efficiency varies modestly over cosmic history. Our survey will permit the most detailed examination to date of the connection between the GRB host population and general star-forming galaxies, directly measure evolution in the host population over cosmic time and discern its causes, and provide new constraints on the fraction of cosmic star formation occurring in undetectable galaxies at all redshifts.

  9. National sample survey to assess the new case disease burden of leprosy in India

    Directory of Open Access Journals (Sweden)

    Kiran Katoch

    2017-01-01

    Full Text Available A national sample survey of leprosy was undertaken in partnership with Indian Council of Medical Research (ICMR institutions, National Leprosy Eradication Programme (NLEP, Panchayati Raj members, and treated leprosy patients to detect new cases of leprosy in India. The objectives of the survey were to estimate the new leprosy case load; record both Grade 1 and Grade 2 disabilities in the new cases; and to assess the magnitude of stigma and discrimination prevalent in the society. A cluster based, cross-sectional survey involving all States was used for the door-to-door survey using inverse sampling methodology. Rural and urban clusters were sampled separately. The population screened for detecting 28 new cases in rural and 30 in urban clusters was enumerated, recorded and analyzed. Data capture and analysis in different schedules were the main tools used. For quality control three tiers of experts were utilized for the confirmation of cases and disabilities. Self-stigma was assessed in more than half of the total new patients detected with disabilities by the approved questionnaire. A different questionnaire was used to assess the stigma in the community. A population of 14,725,525 (10,302,443 rural; 4,423,082 urban was screened and 2161 new cases - 1300 paucibacillary (PB and 861 multibacillary (MB were detected. New case estimates for leprosy was 330,346 (95% Confidence limits, 287,445-380,851. Disabilities observed in these cases were 2.05/100,000 population and 13.9 per cent (302/2161 in new cases. Self-stigma in patients with disabilities was reduced, and the patients were well accepted by the spouse, neighbour, at workplace and in social functions.

  10. Hospital survey on patient safety culture: psychometric analysis on a Scottish sample.

    Science.gov (United States)

    Sarac, Cakil; Flin, Rhona; Mearns, Kathryn; Jackson, Jeanette

    2011-10-01

    To investigate the psychometric properties of the Hospital Survey on Patient Safety Culture on a Scottish NHS data set. The data were collected from 1969 clinical staff (estimated 22% response rate) from one acute hospital from each of seven Scottish Health boards. Using a split-half validation technique, the data were randomly split; an exploratory factor analysis was conducted on the calibration data set, and confirmatory factor analyses were conducted on the validation data set to investigate and check the original US model fit in a Scottish sample. Following the split-half validation technique, exploratory factor analysis results showed a 10-factor optimal measurement model. The confirmatory factor analyses were then performed to compare the model fit of two competing models (10-factor alternative model vs 12-factor original model). An S-B scaled χ(2) square difference test demonstrated that the original 12-factor model performed significantly better in a Scottish sample. Furthermore, reliability analyses of each component yielded satisfactory results. The mean scores on the climate dimensions in the Scottish sample were comparable with those found in other European countries. This study provided evidence that the original 12-factor structure of the Hospital Survey on Patient Safety Culture scale has been replicated in this Scottish sample. Therefore, no modifications are required to the original 12-factor model, which is suggested for use, since it would allow researchers the possibility of cross-national comparisons.

  11. Mapping cell populations in flow cytometry data for cross‐sample comparison using the Friedman–Rafsky test statistic as a distance measure

    Science.gov (United States)

    Hsiao, Chiaowen; Liu, Mengya; Stanton, Rick; McGee, Monnie; Qian, Yu

    2015-01-01

    Abstract Flow cytometry (FCM) is a fluorescence‐based single‐cell experimental technology that is routinely applied in biomedical research for identifying cellular biomarkers of normal physiological responses and abnormal disease states. While many computational methods have been developed that focus on identifying cell populations in individual FCM samples, very few have addressed how the identified cell populations can be matched across samples for comparative analysis. This article presents FlowMap‐FR, a novel method for cell population mapping across FCM samples. FlowMap‐FR is based on the Friedman–Rafsky nonparametric test statistic (FR statistic), which quantifies the equivalence of multivariate distributions. As applied to FCM data by FlowMap‐FR, the FR statistic objectively quantifies the similarity between cell populations based on the shapes, sizes, and positions of fluorescence data distributions in the multidimensional feature space. To test and evaluate the performance of FlowMap‐FR, we simulated the kinds of biological and technical sample variations that are commonly observed in FCM data. The results show that FlowMap‐FR is able to effectively identify equivalent cell populations between samples under scenarios of proportion differences and modest position shifts. As a statistical test, FlowMap‐FR can be used to determine whether the expression of a cellular marker is statistically different between two cell populations, suggesting candidates for new cellular phenotypes by providing an objective statistical measure. In addition, FlowMap‐FR can indicate situations in which inappropriate splitting or merging of cell populations has occurred during gating procedures. We compared the FR statistic with the symmetric version of Kullback–Leibler divergence measure used in a previous population matching method with both simulated and real data. The FR statistic outperforms the symmetric version of KL‐distance in distinguishing

  12. Mapping cell populations in flow cytometry data for cross-sample comparison using the Friedman-Rafsky test statistic as a distance measure.

    Science.gov (United States)

    Hsiao, Chiaowen; Liu, Mengya; Stanton, Rick; McGee, Monnie; Qian, Yu; Scheuermann, Richard H

    2016-01-01

    Flow cytometry (FCM) is a fluorescence-based single-cell experimental technology that is routinely applied in biomedical research for identifying cellular biomarkers of normal physiological responses and abnormal disease states. While many computational methods have been developed that focus on identifying cell populations in individual FCM samples, very few have addressed how the identified cell populations can be matched across samples for comparative analysis. This article presents FlowMap-FR, a novel method for cell population mapping across FCM samples. FlowMap-FR is based on the Friedman-Rafsky nonparametric test statistic (FR statistic), which quantifies the equivalence of multivariate distributions. As applied to FCM data by FlowMap-FR, the FR statistic objectively quantifies the similarity between cell populations based on the shapes, sizes, and positions of fluorescence data distributions in the multidimensional feature space. To test and evaluate the performance of FlowMap-FR, we simulated the kinds of biological and technical sample variations that are commonly observed in FCM data. The results show that FlowMap-FR is able to effectively identify equivalent cell populations between samples under scenarios of proportion differences and modest position shifts. As a statistical test, FlowMap-FR can be used to determine whether the expression of a cellular marker is statistically different between two cell populations, suggesting candidates for new cellular phenotypes by providing an objective statistical measure. In addition, FlowMap-FR can indicate situations in which inappropriate splitting or merging of cell populations has occurred during gating procedures. We compared the FR statistic with the symmetric version of Kullback-Leibler divergence measure used in a previous population matching method with both simulated and real data. The FR statistic outperforms the symmetric version of KL-distance in distinguishing equivalent from nonequivalent cell

  13. Optimum strata boundaries and sample sizes in health surveys using auxiliary variables.

    Science.gov (United States)

    Reddy, Karuna Garan; Khan, Mohammad G M; Khan, Sabiha

    2018-01-01

    Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves higher precision in the estimation. In this paper, a procedure for determining Optimum Stratum Boundaries (OSB) and Optimum Sample Sizes (OSS) for each stratum of a variable of interest in health surveys is developed. The determination of OSB and OSS based on the study variable is not feasible in practice since the study variable is not available prior to the survey. Since many variables in health surveys are generally skewed, the proposed technique considers the readily-available auxiliary variables to determine the OSB and OSS. This stratification problem is formulated into a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. It is then solved for the OSB by using a dynamic programming (DP) technique. A numerical example with a real data set of a population, aiming to estimate the Haemoglobin content in women in a national Iron Deficiency Anaemia survey, is presented to illustrate the procedure developed in this paper. Upon comparisons with other methods available in literature, results reveal that the proposed approach yields a substantial gain in efficiency over the other methods. A simulation study also reveals similar results.

  14. Men who have sex with men in Great Britain: comparing methods and estimates from probability and convenience sample surveys

    OpenAIRE

    Prah, Philip; Hickson, Ford; Bonell, Chris; McDaid, Lisa M; Johnson, Anne M; Wayal, Sonali; Clifton, Soazig; Sonnenberg, Pam; Nardone, Anthony; Erens, Bob; Copas, Andrew J; Riddell, Julie; Weatherburn, Peter; Mercer, Catherine H

    2016-01-01

    Objective: To examine sociodemographic and behavioural differences between men whohave sex with men (MSM) participating in recent UK convenience surveys and a national probability sample survey.\\ud Methods: We compared 148 MSM aged 18–64 years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) undertaken in 2010–2012, with men inthe same age range participating in contemporaneous convenience surveys of MSM: 15 500 British resident men in the European...

  15. A Survey for Spectroscopic Binaries in a Large Sample of G Dwarfs

    Science.gov (United States)

    Udry, S.; Mayor, M.; Latham, D. W.; Stefanik, R. P.; Torres, G.; Mazeh, T.; Goldberg, D.; Andersen, J.; Nordstrom, B.

    For more than 5 years now, the radial velocities for a large sample of G dwarfs (3,347 stars) have been monitored in order to obtain an unequaled set of orbital parameters for solar-type stars (~400 orbits, up to now). This survey provides a considerable improvement on the classical systematic study by Duquennoy and Mayor (1991; DM91). The observational part of the survey has been carried out in the context of a collaboration between the Geneva Observatory on the two coravel spectrometers for the southern sky and CfA at Oakridge and Whipple Observatories for the northern sky. As a first glance at these new results, we will address in this contribution a special aspect of the orbital eccentricity distribution, namely the disappearance of the void observed in DM91 for quasi-circular orbits with periods larger than 10 days.

  16. A survey of the knowledge, use, and adoption of emerging technologies by academics in an Open Distance Learning environment

    Directory of Open Access Journals (Sweden)

    B Chimbo

    2014-07-01

    Full Text Available The realisation of the advantages offered by e-learning accompanied by the use of various emerging information technologies has resulted in a noticeable shift by academia towards e-learning. An analysis of the use, knowledge and adoption of emerging technologies by academics in an Open Distance Learning (ODL environment at the University of South Africa (UNISA was undertaken in this study. The aim of the study was to evaluate the use, knowledge and adoption of emerging e-learning technologies by the academics from the selected schools. The academics in the Schools of Arts, Computing and Science were purposively selected in order to draw on views of academics from different teaching and educational backgrounds. Questionnaires were distributed both electronically and manually. The results showed that academics in all the Schools were competent at the use of information technology tools and applications such as emailing, word-processing, Internet, myUnisa (UNISA’s online teaching platform, and Microsoft PowerPoint and Excel. An evaluation of the awareness of different emerging technological tools showed that most academics were aware of Open Access Technologies, Social Networking Sites, Blogs, Video Games and Microblogging Platforms. While the level of awareness was high for these technologies, the use by the academics was low. At least 62.3% of the academics indicated willingness to migrate to online teaching completely and also indicated the need for further training on new technologies. A comparison of the different schools showed no statistically significant difference in the use, knowledge and willingness to adopt technology amongst the academics.

  17. Men who have sex with men in Great Britain: comparing methods and estimates from probability and convenience sample surveys.

    Science.gov (United States)

    Prah, Philip; Hickson, Ford; Bonell, Chris; McDaid, Lisa M; Johnson, Anne M; Wayal, Sonali; Clifton, Soazig; Sonnenberg, Pam; Nardone, Anthony; Erens, Bob; Copas, Andrew J; Riddell, Julie; Weatherburn, Peter; Mercer, Catherine H

    2016-09-01

    To examine sociodemographic and behavioural differences between men who have sex with men (MSM) participating in recent UK convenience surveys and a national probability sample survey. We compared 148 MSM aged 18-64 years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) undertaken in 2010-2012, with men in the same age range participating in contemporaneous convenience surveys of MSM: 15 500 British resident men in the European MSM Internet Survey (EMIS); 797 in the London Gay Men's Sexual Health Survey; and 1234 in Scotland's Gay Men's Sexual Health Survey. Analyses compared men reporting at least one male sexual partner (past year) on similarly worded questions and multivariable analyses accounted for sociodemographic differences between the surveys. MSM in convenience surveys were younger and better educated than MSM in Natsal-3, and a larger proportion identified as gay (85%-95% vs 62%). Partner numbers were higher and same-sex anal sex more common in convenience surveys. Unprotected anal intercourse was more commonly reported in EMIS. Compared with Natsal-3, MSM in convenience surveys were more likely to report gonorrhoea diagnoses and HIV testing (both past year). Differences between the samples were reduced when restricting analysis to gay-identifying MSM. National probability surveys better reflect the population of MSM but are limited by their smaller samples of MSM. Convenience surveys recruit larger samples of MSM but tend to over-represent MSM identifying as gay and reporting more sexual risk behaviours. Because both sampling strategies have strengths and weaknesses, methods are needed to triangulate data from probability and convenience surveys. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  18. Men who have sex with men in Great Britain: comparing methods and estimates from probability and convenience sample surveys

    Science.gov (United States)

    Prah, Philip; Hickson, Ford; Bonell, Chris; McDaid, Lisa M; Johnson, Anne M; Wayal, Sonali; Clifton, Soazig; Sonnenberg, Pam; Nardone, Anthony; Erens, Bob; Copas, Andrew J; Riddell, Julie; Weatherburn, Peter; Mercer, Catherine H

    2016-01-01

    Objective To examine sociodemographic and behavioural differences between men who have sex with men (MSM) participating in recent UK convenience surveys and a national probability sample survey. Methods We compared 148 MSM aged 18–64 years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) undertaken in 2010–2012, with men in the same age range participating in contemporaneous convenience surveys of MSM: 15 500 British resident men in the European MSM Internet Survey (EMIS); 797 in the London Gay Men's Sexual Health Survey; and 1234 in Scotland's Gay Men's Sexual Health Survey. Analyses compared men reporting at least one male sexual partner (past year) on similarly worded questions and multivariable analyses accounted for sociodemographic differences between the surveys. Results MSM in convenience surveys were younger and better educated than MSM in Natsal-3, and a larger proportion identified as gay (85%–95% vs 62%). Partner numbers were higher and same-sex anal sex more common in convenience surveys. Unprotected anal intercourse was more commonly reported in EMIS. Compared with Natsal-3, MSM in convenience surveys were more likely to report gonorrhoea diagnoses and HIV testing (both past year). Differences between the samples were reduced when restricting analysis to gay-identifying MSM. Conclusions National probability surveys better reflect the population of MSM but are limited by their smaller samples of MSM. Convenience surveys recruit larger samples of MSM but tend to over-represent MSM identifying as gay and reporting more sexual risk behaviours. Because both sampling strategies have strengths and weaknesses, methods are needed to triangulate data from probability and convenience surveys. PMID:26965869

  19. Sampling and Analysis Plan for Supplemental Environmental Project: Aquatic Life Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Berryhill, Jesse Tobias [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gaukler, Shannon Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-26

    As part of a settlement agreement for nuclear waste incidents in 2014, several supplemental environment projects (SEPs) were initiated at Los Alamos National Laboratory (LANL or the Laboratory) between the U.S. Department of Energy and the state of New Mexico. One SEP from this agreement consists of performing aquatic life surveys and will be used to assess the applicability of using generic ambient water-quality criteria (AWQC) for aquatic life. AWQC are generic criteria developed by the U.S. Environmental Protection Agency (EPA) to cover a broad range of aquatic species and are not unique to a specific region or state. AWQC are established by a composition of toxicity data, called species sensitivity distributions (SSDs), and are determined by LC50 (lethal concentration of 50% of the organisms studied) acute toxicity experiments for chemicals of interest. It is of interest to determine whether aquatic species inhabiting waters on the Pajarito Plateau are adequately protected using the current generic AWQC. The focus of this study will determine which aquatic species are present in ephemeral, intermittent, and perennial waters within LANL boundaries and from reference waters adjacent to LANL. If the species identified from these waters do not generally represent species used in the SSDs, then SSDs may need to be modified and AWQC may need to be updated. This sampling and analysis plan details the sampling methodology, surveillance locations, temporal scheduling, and analytical approaches that will be used to complete aquatic life surveys. A significant portion of this sampling and analysis plan was formalized by referring to Appendix E: SEP Aquatic Life Surveys DQO (Data Quality Objectives).

  20. Optimum sample size to estimate mean parasite abundance in fish parasite surveys

    Directory of Open Access Journals (Sweden)

    Shvydka S.

    2018-03-01

    Full Text Available To reach ethically and scientifically valid mean abundance values in parasitological and epidemiological studies this paper considers analytic and simulation approaches for sample size determination. The sample size estimation was carried out by applying mathematical formula with predetermined precision level and parameter of the negative binomial distribution estimated from the empirical data. A simulation approach to optimum sample size determination aimed at the estimation of true value of the mean abundance and its confidence interval (CI was based on the Bag of Little Bootstraps (BLB. The abundance of two species of monogenean parasites Ligophorus cephali and L. mediterraneus from Mugil cephalus across the Azov-Black Seas localities were subjected to the analysis. The dispersion pattern of both helminth species could be characterized as a highly aggregated distribution with the variance being substantially larger than the mean abundance. The holistic approach applied here offers a wide range of appropriate methods in searching for the optimum sample size and the understanding about the expected precision level of the mean. Given the superior performance of the BLB relative to formulae with its few assumptions, the bootstrap procedure is the preferred method. Two important assessments were performed in the present study: i based on CIs width a reasonable precision level for the mean abundance in parasitological surveys of Ligophorus spp. could be chosen between 0.8 and 0.5 with 1.6 and 1x mean of the CIs width, and ii the sample size equal 80 or more host individuals allows accurate and precise estimation of mean abundance. Meanwhile for the host sample size in range between 25 and 40 individuals, the median estimates showed minimal bias but the sampling distribution skewed to the low values; a sample size of 10 host individuals yielded to unreliable estimates.

  1. Using the Superpopulation Model for Imputations and Variance Computation in Survey Sampling

    Directory of Open Access Journals (Sweden)

    Petr Novák

    2012-03-01

    Full Text Available This study is aimed at variance computation techniques for estimates of population characteristics based on survey sampling and imputation. We use the superpopulation regression model, which means that the target variable values for each statistical unit are treated as random realizations of a linear regression model with weighted variance. We focus on regression models with one auxiliary variable and no intercept, which have many applications and straightforward interpretation in business statistics. Furthermore, we deal with caseswhere the estimates are not independent and thus the covariance must be computed. We also consider chained regression models with auxiliary variables as random variables instead of constants.

  2. Revised Distances to 21 Supernova Remnants

    Science.gov (United States)

    Ranasinghe, S.; Leahy, D. A.

    2018-05-01

    We carry out a comprehensive study of H I 21 cm line observations and 13CO line observations of 21 supernova remnants (SNRs). The aim of the study is to search for H I absorption features to obtain kinematic distances in a consistent manner. The 21 SNRs are in the region of sky covered by the Very Large Array Galactic Plane Survey (H I 21 cm observations) and Galactic Ring Survey (13CO line observations). We obtain revised distances for 10 SNRs based on new evidence in the H I and 13CO observations. We revise distances for the other 11 SNRs based on an updated rotation curve and new error analysis. The mean change in distance for the 21 SNRs is ≃25%, i.e., a change of 1.5 kpc compared to a mean distance for the sample of 6.4 kpc. This has a significant impact on interpretation of the physical state of these SNRs. For example, using a Sedov model, age and explosion energy scale as the square of distance, and inferred ISM density scales as distance.

  3. Real-Time Pathogen Detection in the Era of Whole-Genome Sequencing and Big Data: Comparison of k-mer and Site-Based Methods for Inferring the Genetic Distances among Tens of Thousands of Salmonella Samples.

    Directory of Open Access Journals (Sweden)

    James B Pettengill

    Full Text Available The adoption of whole-genome sequencing within the public health realm for molecular characterization of bacterial pathogens has been followed by an increased emphasis on real-time detection of emerging outbreaks (e.g., food-borne Salmonellosis. In turn, large databases of whole-genome sequence data are being populated. These databases currently contain tens of thousands of samples and are expected to grow to hundreds of thousands within a few years. For these databases to be of optimal use one must be able to quickly interrogate them to accurately determine the genetic distances among a set of samples. Being able to do so is challenging due to both biological (evolutionary diverse samples and computational (petabytes of sequence data issues. We evaluated seven measures of genetic distance, which were estimated from either k-mer profiles (Jaccard, Euclidean, Manhattan, Mash Jaccard, and Mash distances or nucleotide sites (NUCmer and an extended multi-locus sequence typing (MLST scheme. When analyzing empirical data (whole-genome sequence data from 18,997 Salmonella isolates there are features (e.g., genomic, assembly, and contamination that cause distances inferred from k-mer profiles, which treat absent data as informative, to fail to accurately capture the distance between samples when compared to distances inferred from differences in nucleotide sites. Thus, site-based distances, like NUCmer and extended MLST, are superior in performance, but accessing the computing resources necessary to perform them may be challenging when analyzing large databases.

  4. Real-Time Pathogen Detection in the Era of Whole-Genome Sequencing and Big Data: Comparison of k-mer and Site-Based Methods for Inferring the Genetic Distances among Tens of Thousands of Salmonella Samples.

    Science.gov (United States)

    Pettengill, James B; Pightling, Arthur W; Baugher, Joseph D; Rand, Hugh; Strain, Errol

    2016-01-01

    The adoption of whole-genome sequencing within the public health realm for molecular characterization of bacterial pathogens has been followed by an increased emphasis on real-time detection of emerging outbreaks (e.g., food-borne Salmonellosis). In turn, large databases of whole-genome sequence data are being populated. These databases currently contain tens of thousands of samples and are expected to grow to hundreds of thousands within a few years. For these databases to be of optimal use one must be able to quickly interrogate them to accurately determine the genetic distances among a set of samples. Being able to do so is challenging due to both biological (evolutionary diverse samples) and computational (petabytes of sequence data) issues. We evaluated seven measures of genetic distance, which were estimated from either k-mer profiles (Jaccard, Euclidean, Manhattan, Mash Jaccard, and Mash distances) or nucleotide sites (NUCmer and an extended multi-locus sequence typing (MLST) scheme). When analyzing empirical data (whole-genome sequence data from 18,997 Salmonella isolates) there are features (e.g., genomic, assembly, and contamination) that cause distances inferred from k-mer profiles, which treat absent data as informative, to fail to accurately capture the distance between samples when compared to distances inferred from differences in nucleotide sites. Thus, site-based distances, like NUCmer and extended MLST, are superior in performance, but accessing the computing resources necessary to perform them may be challenging when analyzing large databases.

  5. [Comparison study on sampling methods of Oncomelania hupensis snail survey in marshland schistosomiasis epidemic areas in China].

    Science.gov (United States)

    An, Zhao; Wen-Xin, Zhang; Zhong, Yao; Yu-Kuan, Ma; Qing, Liu; Hou-Lang, Duan; Yi-di, Shang

    2016-06-29

    To optimize and simplify the survey method of Oncomelania hupensis snail in marshland endemic region of schistosomiasis and increase the precision, efficiency and economy of the snail survey. A quadrate experimental field was selected as the subject of 50 m×50 m size in Chayegang marshland near Henghu farm in the Poyang Lake region and a whole-covered method was adopted to survey the snails. The simple random sampling, systematic sampling and stratified random sampling methods were applied to calculate the minimum sample size, relative sampling error and absolute sampling error. The minimum sample sizes of the simple random sampling, systematic sampling and stratified random sampling methods were 300, 300 and 225, respectively. The relative sampling errors of three methods were all less than 15%. The absolute sampling errors were 0.221 7, 0.302 4 and 0.047 8, respectively. The spatial stratified sampling with altitude as the stratum variable is an efficient approach of lower cost and higher precision for the snail survey.

  6. BMR in a Brazilian adult probability sample: the Nutrition, Physical Activity and Health Survey.

    Science.gov (United States)

    Anjos, Luiz A; Wahrlich, Vivian; Vasconcellos, Mauricio Tl

    2014-04-01

    To measure BMR in a probability sample of adults from an urban city of Brazil and to compare indirectly measured BMR (BMRi) with BMR predicted from different equations. BMR data were obtained by indirect calorimetry and estimated by different predictive equations (Schofield; Harris and Benedict; Henry and Rees). Anthropometric and body composition measures were also obtained. The Nutrition, Physical Activity and Health Survey (PNAFS), a household survey conducted in Niterói, Rio de Janeiro state, Brazil. Representative sample of 529 adults (aged ≥20 years; 339 females) living in Niterói, Rio de Janeiro state, Brazil. Mean BMRi values were 5839.7 (se 73.9) kJ/d and 4758.1 (se 39.5) kJ/d for men and women, respectively. Predicted BMR by all equations was significantly higher (difference between means and 95% CI did not include zero) than BMRi in both men and women of all ages. Overall bias in BMR (predicted BMR minus BMRi) using the Schofield equations (overestimation of about 20%) was higher than when using the Henry and Rees equations (13% and 16% overestimation for males and females, respectively). The percentage of individuals whose BMR predicted by the Schofield equations fell within 10% of BMRi was very low (7.8% and 14.1% of males nd females, respectively). Current available predictive equations of BMR are not adequate to estimate BMR in Brazilians living in Niterói, Rio de Janeiro, Brazil.

  7. The SAGES Legacy Unifying Globulars and Galaxies survey (SLUGGS): sample definition, methods, and initial results

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, Jean P.; Romanowsky, Aaron J.; Jennings, Zachary G.; Pota, Vincenzo; Kader, Justin; Roediger, Joel C.; Villaume, Alexa; Arnold, Jacob A.; Woodley, Kristin A. [University of California Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Strader, Jay [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Forbes, Duncan A.; Pastorello, Nicola; Usher, Christopher; Blom, Christina; Kartha, Sreeja S. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Foster, Caroline; Spitler, Lee R., E-mail: jbrodie@ucsc.edu [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)

    2014-11-20

    We introduce and provide the scientific motivation for a wide-field photometric and spectroscopic chemodynamical survey of nearby early-type galaxies (ETGs) and their globular cluster (GC) systems. The SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey is being carried out primarily with Subaru/Suprime-Cam and Keck/DEIMOS. The former provides deep gri imaging over a 900 arcmin{sup 2} field-of-view to characterize GC and host galaxy colors and spatial distributions, and to identify spectroscopic targets. The NIR Ca II triplet provides GC line-of-sight velocities and metallicities out to typically ∼8 R {sub e}, and to ∼15 R {sub e} in some cases. New techniques to extract integrated stellar kinematics and metallicities to large radii (∼2-3 R {sub e}) are used in concert with GC data to create two-dimensional (2D) velocity and metallicity maps for comparison with simulations of galaxy formation. The advantages of SLUGGS compared with other, complementary, 2D-chemodynamical surveys are its superior velocity resolution, radial extent, and multiple halo tracers. We describe the sample of 25 nearby ETGs, the selection criteria for galaxies and GCs, the observing strategies, the data reduction techniques, and modeling methods. The survey observations are nearly complete and more than 30 papers have so far been published using SLUGGS data. Here we summarize some initial results, including signatures of two-phase galaxy assembly, evidence for GC metallicity bimodality, and a novel framework for the formation of extended star clusters and ultracompact dwarfs. An integrated overview of current chemodynamical constraints on GC systems points to separate, in situ formation modes at high redshifts for metal-poor and metal-rich GCs.

  8. Measuring the health of the Indian elderly: evidence from National Sample Survey data

    Directory of Open Access Journals (Sweden)

    Mahal Ajay

    2010-11-01

    Full Text Available Abstract Background Comparable health measures across different sets of populations are essential for describing the distribution of health outcomes and assessing the impact of interventions on these outcomes. Self-reported health (SRH is a commonly used indicator of health in household surveys and has been shown to be predictive of future mortality. However, the susceptibility of SRH to influence by individuals' expectations complicates its interpretation and undermines its usefulness. Methods This paper applies the empirical methodology of Lindeboom and van Doorslaer (2004 to investigate elderly health in India using data from the 52nd round of the National Sample Survey conducted in 1995-96 that includes both an SRH variable as well as a range of objective indicators of disability and ill health. The empirical testing was conducted on stratified homogeneous groups, based on four factors: gender, education, rural-urban residence, and region. Results We find that region generally has a significant impact on how women perceive their health. Reporting heterogeneity can arise not only from cut-point shifts, but also from differences in health effects by objective health measures. In contrast, we find little evidence of reporting heterogeneity due to differences in gender or educational status within regions. Rural-urban residence does matter in some cases. The findings are robust with different specifications of objective health indicators. Conclusions Our exercise supports the thesis that the region of residence is associated with different cut-points and reporting behavior on health surveys. We believe this is the first paper that applies the Lindeboom-van Doorslaer methodology to data on the elderly in a developing country, showing the feasibility of applying this methodology to data from many existing cross-sectional health surveys.

  9. Does self-selection affect samples' representativeness in online surveys? An investigation in online video game research.

    Science.gov (United States)

    Khazaal, Yasser; van Singer, Mathias; Chatton, Anne; Achab, Sophia; Zullino, Daniele; Rothen, Stephane; Khan, Riaz; Billieux, Joel; Thorens, Gabriel

    2014-07-07

    The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online studies is patchy. Our objective was to explore the representativeness of a self-selected sample of online gamers using online players' virtual characters (avatars). All avatars belonged to individuals playing World of Warcraft (WoW), currently the most widely used online game. Avatars' characteristics were defined using various games' scores, reported on the WoW's official website, and two self-selected samples from previous studies were compared with a randomly selected sample of avatars. We used scores linked to 1240 avatars (762 from the self-selected samples and 478 from the random sample). The two self-selected samples of avatars had higher scores on most of the assessed variables (except for guild membership and exploration). Furthermore, some guilds were overrepresented in the self-selected samples. Our results suggest that more proficient players or players more involved in the game may be more likely to participate in online surveys. Caution is needed in the interpretation of studies based on online surveys that used a self-selection recruitment procedure. Epidemiological evidence on the reduced representativeness of sample of online surveys is warranted.

  10. The Lyα reference sample. I. Survey outline and first results for Markarian 259

    International Nuclear Information System (INIS)

    Östlin, Göran; Hayes, Matthew; Duval, Florent; Sandberg, Andreas; Rivera-Thorsen, Thøger; Marquart, Thomas; Adamo, Angela; Melinder, Jens; Guaita, Lucia; Micheva, Genoveva; Orlitová, Ivana; Atek, Hakim; Cannon, John M.; Pardy, Stephen A.; Gruyters, Pieter; Herenz, Edmund Christian; Kunth, Daniel; Laursen, Peter; Mas-Hesse, J. Miguel; Otí-Floranes, Héctor

    2014-01-01

    The Lyα Reference Sample (LARS) is a substantial program with the Hubble Space Telescope (HST) that provides a sample of local universe laboratory galaxies in which to study the detailed astrophysics of the visibility and strength of the Lyαline of neutral hydrogen. Lyα is the dominant spectral line in use for characterizing high-redshift (z) galaxies. This paper presents an overview of the survey, its selection function, and HST imaging observations. The sample was selected from the combined GALEX+Sloan Digital Sky Survey catalog at z = 0.028-0.19, in order to allow Lyα to be captured with combinations of long-pass filters in the Solar Blind Channel (SBC) of the Advanced Camera for Surveys (ACS) onboard HST. In addition, LARS utilizes Hα and Hβ narrowband and u, b, i broadband imaging with ACS and the Wide Field Camera 3 (WFC3). In order to study galaxies in which large numbers of Lyα photons are produced (whether or not they escape), we demanded an Hα equivalent width W(Hα) ≥100 Å. The final sample of 14 galaxies covers far-UV (FUV, λ ∼ 1500 Å) luminosities that overlap with those of high-z Lyα emitters (LAEs) and Lyman break galaxies (LBGs), making LARS a valid comparison sample. We present the reduction steps used to obtain the Lyα images, including our LARS eXtraction software (LaXs), which utilizes pixel-by-pixel spectral synthesis fitting of the energy distribution to determine and subtract the continuum at Lyα. We demonstrate that the use of SBC long-pass-filter combinations increase the signal-to-noise ratio by an order of magnitude compared to the nominal Lyα filter available in SBC. To exemplify the science potential of LARS, we also present some first results for a single galaxy, Mrk 259 (LARS #1). This irregular galaxy shows bright and extended (indicative of resonance scattering) but strongly asymmetric Lyα emission. Spectroscopy from the Cosmic Origins Spectrograph on board HST centered on the brightest UV knot shows a moderate

  11. The Lyα reference sample. I. Survey outline and first results for Markarian 259

    Energy Technology Data Exchange (ETDEWEB)

    Östlin, Göran; Hayes, Matthew; Duval, Florent; Sandberg, Andreas; Rivera-Thorsen, Thøger; Marquart, Thomas; Adamo, Angela; Melinder, Jens; Guaita, Lucia; Micheva, Genoveva [Department of Astronomy, Stockholm University, Oscar Klein Centre, AlbaNova, Stockholm SE-106 91 (Sweden); Orlitová, Ivana [Observatoire de Genève, Université de Genève, Chemin des Maillettes 51, 1290 Versoix (Switzerland); Atek, Hakim [Laboratoire d' Astrophysique, Ecole Polytechnique Fédérale de Lausanne, Observatoire de Sauverny, CH-1290 Versoix (Switzerland); Cannon, John M.; Pardy, Stephen A. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Gruyters, Pieter [Department of Physics and Astronomy, Division of Astronomy and Space Physics, Uppsala University, Box 516, 75120 Uppsala (Sweden); Herenz, Edmund Christian [Leibniz-Institute for Astrophysics Potsdam (AIP), innoFSPEC, An der Sternwarte 16, D-14482 Potsdam (Germany); Kunth, Daniel [Institut d' Astrophysique Paris, 98bis Bd Arago, F-75014 Paris (France); Laursen, Peter [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Mas-Hesse, J. Miguel [Centro de Astrobiologa (CSIC-INTA), Departamento de Astrofsica, POB 78, E-28691, Villanueva de la Cañada (Spain); Otí-Floranes, Héctor [Instituto de Astronoma, Universidad Nacional Autnoma de Mxico, Apdo. Postal 106, Ensenada B. C. 22800 (Mexico); and others

    2014-12-10

    The Lyα Reference Sample (LARS) is a substantial program with the Hubble Space Telescope (HST) that provides a sample of local universe laboratory galaxies in which to study the detailed astrophysics of the visibility and strength of the Lyαline of neutral hydrogen. Lyα is the dominant spectral line in use for characterizing high-redshift (z) galaxies. This paper presents an overview of the survey, its selection function, and HST imaging observations. The sample was selected from the combined GALEX+Sloan Digital Sky Survey catalog at z = 0.028-0.19, in order to allow Lyα to be captured with combinations of long-pass filters in the Solar Blind Channel (SBC) of the Advanced Camera for Surveys (ACS) onboard HST. In addition, LARS utilizes Hα and Hβ narrowband and u, b, i broadband imaging with ACS and the Wide Field Camera 3 (WFC3). In order to study galaxies in which large numbers of Lyα photons are produced (whether or not they escape), we demanded an Hα equivalent width W(Hα) ≥100 Å. The final sample of 14 galaxies covers far-UV (FUV, λ ∼ 1500 Å) luminosities that overlap with those of high-z Lyα emitters (LAEs) and Lyman break galaxies (LBGs), making LARS a valid comparison sample. We present the reduction steps used to obtain the Lyα images, including our LARS eXtraction software (LaXs), which utilizes pixel-by-pixel spectral synthesis fitting of the energy distribution to determine and subtract the continuum at Lyα. We demonstrate that the use of SBC long-pass-filter combinations increase the signal-to-noise ratio by an order of magnitude compared to the nominal Lyα filter available in SBC. To exemplify the science potential of LARS, we also present some first results for a single galaxy, Mrk 259 (LARS #1). This irregular galaxy shows bright and extended (indicative of resonance scattering) but strongly asymmetric Lyα emission. Spectroscopy from the Cosmic Origins Spectrograph on board HST centered on the brightest UV knot shows a moderate

  12. Very high precision survey equipment for great distances Surface surveys used to map out the surface network and the tunnelling machines then gyroscopically steered underground.

    CERN Document Server

    1983-01-01

    At the beginning of the 1980s, CERN embarked on the enormous Large Electron-Positron Collider construction project. The excavation of the 27-kilometre LEP tunnel was a huge technical challenge. The tunnel-boring machines excavated the tunnel in 3.3 km octants and had to be operated with extraordinary precision to ensure that they reached their destination - the bottom of the next vertical shaft - precisely on target. The tunnel was excavated before high-performance instruments were developed for the construction of the Channel Tunnel. As no firms were willing to perform the surveying work, CERN's own surveyors, with experience from the SPS behind them, took up the challenge. At the surface, the surveyors established the world's most accurate geodetic network, performing measurements to an accuracy of 10-7, or 1mm per 10 km, using the Terrameter (see photo). The excavation of the tunnel was completed in 1988 and the finished tunnel's trajectory was found to diverge from the theoretical value specified by the p...

  13. Sampling and analysis plan for the preoperational environmental survey for the immobilized low activity waste (ILAW) project W-465

    International Nuclear Information System (INIS)

    Mitchell, R.M.

    1998-01-01

    This document provides a detailed description of the Sampling and Analysis Plan for the Preoperational Survey to be conducted at the Immobilized Low Activity Waste (ILAW) Project Site in the 200 East Area

  14. Nested PCR detection of malaria directly using blood filter paper samples from epidemiological surveys.

    Science.gov (United States)

    Li, Peipei; Zhao, Zhenjun; Wang, Ying; Xing, Hua; Parker, Daniel M; Yang, Zhaoqing; Baum, Elizabeth; Li, Wenli; Sattabongkot, Jetsumon; Sirichaisinthop, Jeeraphat; Li, Shuying; Yan, Guiyun; Cui, Liwang; Fan, Qi

    2014-05-08

    Nested PCR is considered a sensitive and specific method for detecting malaria parasites and is especially useful in epidemiological surveys. However, the preparation of DNA templates for PCR is often time-consuming and costly. A simplified PCR method was developed to directly use a small blood filter paper square (2 × 2 mm) as the DNA template after treatment with saponin. This filter paper-based nested PCR method (FP-PCR) was compared to microscopy and standard nested PCR with DNA extracted by using a Qiagen DNA mini kit from filter paper blood spots of 204 febrile cases. The FP-PCR technique was further applied to evaluate malaria infections in 1,708 participants from cross-sectional epidemiological surveys conducted in Myanmar and Thailand. The FP-PCR method had a detection limit of ~0.2 parasites/μL blood, estimated using cultured Plasmodium falciparum parasites. With 204 field samples, the sensitivity of the FP-PCR method was comparable to that of the standard nested PCR method, which was significantly higher than that of microscopy. Application of the FP-PCR method in large cross-sectional studies conducted in Myanmar and Thailand detected 1.9% (12/638) and 6.2% (66/1,070) asymptomatic Plasmodium infections, respectively, as compared to the detection rates of 1.3% (8/638) and 0.04% (4/1,070) by microscopy. This FP-PCR method was much more sensitive than microscopy in detecting Plasmodium infections. It drastically increased the detection sensitivity of asymptomatic infections in cross-sectional surveys conducted in Thailand and Myanmar, suggesting that this FP-PCR method has a potential for future applications in malaria epidemiology studies.

  15. The prevalence of workaholism: a survey study in a nationally representative sample of Norwegian employees.

    Directory of Open Access Journals (Sweden)

    Cecilie Schou Andreassen

    Full Text Available Workaholism has become an increasingly popular area for empirical study. However, most studies examining the prevalence of workaholism have used non-representative samples and measures with poorly defined cut-off scores. To overcome these methodological limitations, a nationally representative survey among employees in Norway (N = 1,124 was conducted. Questions relating to gender, age, marital status, caretaker responsibility for children, percentage of full-time equivalent, and educational level were asked. Workaholism was assessed by the use of a psychometrically validated instrument (i.e., Bergen Work Addiction Scale. Personality was assessed using the Mini-International Personality Item Pool. Results showed that the prevalence of workaholism was 8.3% (95% CI  = 6.7-9.9%. An adjusted logistic regression analysis showed that workaholism was negatively related to age and positively related to the personality dimensions agreeableness, neuroticism, and intellect/imagination. Implications for these findings are discussed.

  16. Penggunaan Metode Respondent Driven Sampling (Rds dalam Survey Pemasaran Beras di Provinsi Kepulauan Riau

    Directory of Open Access Journals (Sweden)

    Herena Pudjihastuti

    2014-06-01

    Full Text Available As a Free Trade Zone (FTZ, the province of Riau Islands has a different pattern of strategic commodity (such as rice marketing comparing to other regions in Indonesia. To anticipate and control the negative effects of the implementation of FTZ policy, It is necessary to study about rice marketing trade system in the Riau Islands region. The study was conducted to identify patterns of supply and marketing of food (rice and analyze the marketing margin and marketing efficiency as well as the factors that influence it. The study was conducted through desk study and field surveys. Secondary data was collected from various sources and primary data collected through interviews with selected respondents using Respondent Driven Sampling method (RDS. The study shows that the structure of the rice market in Riau Islands can be categorized as monopolistic. Most of the rice supply comes from outside the region and import, the supply chain is quite simple, the price is relatively stable and relatively efficient marketing and resilience of rice reserves are relatively high for merchants. Nevertheless, the Riau islands will be very susceptible to interference distribution. Required efforts of the provincial government of Riau Islands to provide sufficient rice reserves. This paper gives an example of the use of the RDS method in marketing surveys.

  17. Explaining health care expenditure variation: large-sample evidence using linked survey and health administrative data.

    Science.gov (United States)

    Ellis, Randall P; Fiebig, Denzil G; Johar, Meliyanni; Jones, Glenn; Savage, Elizabeth

    2013-09-01

    Explaining individual, regional, and provider variation in health care spending is of enormous value to policymakers but is often hampered by the lack of individual level detail in universal public health systems because budgeted spending is often not attributable to specific individuals. Even rarer is self-reported survey information that helps explain this variation in large samples. In this paper, we link a cross-sectional survey of 267 188 Australians age 45 and over to a panel dataset of annual healthcare costs calculated from several years of hospital, medical and pharmaceutical records. We use this data to distinguish between cost variations due to health shocks and those that are intrinsic (fixed) to an individual over three years. We find that high fixed expenditures are positively associated with age, especially older males, poor health, obesity, smoking, cancer, stroke and heart conditions. Being foreign born, speaking a foreign language at home and low income are more strongly associated with higher time-varying expenditures, suggesting greater exposure to adverse health shocks. Copyright © 2013 John Wiley & Sons, Ltd.

  18. The Italian national survey on radon indoors run by several different regional laboratories: Sampling strategy, realization and follow-up

    International Nuclear Information System (INIS)

    Bochicchio, F.; Risica, S.; Piermattei, S.

    1993-01-01

    The paper outlines the criteria and organization adopted by the Italian National Institutions in carrying out a representative national survey to evaluate the distribution of radon concentration and the exposure of the Italian population to natural radiation indoors. The main items of the survey - i.e. sampling design, choice of the sample size (5000 dwellings), organization, analysis of the actual sample structure, questionnaire to collect data about families and their dwellings, experimental set up and communication with the public - are discussed. Some results, concerning a first fraction of the total sample, are also presented. (author). 13 refs, 2 figs, 2 tabs

  19. modelling distances

    Directory of Open Access Journals (Sweden)

    Robert F. Love

    2001-01-01

    Full Text Available Distance predicting functions may be used in a variety of applications for estimating travel distances between points. To evaluate the accuracy of a distance predicting function and to determine its parameters, a goodness-of-fit criteria is employed. AD (Absolute Deviations, SD (Squared Deviations and NAD (Normalized Absolute Deviations are the three criteria that are mostly employed in practice. In the literature some assumptions have been made about the properties of each criterion. In this paper, we present statistical analyses performed to compare the three criteria from different perspectives. For this purpose, we employ the ℓkpθ-norm as the distance predicting function, and statistically compare the three criteria by using normalized absolute prediction error distributions in seventeen geographical regions. We find that there exist no significant differences between the criteria. However, since the criterion SD has desirable properties in terms of distance modelling procedures, we suggest its use in practice.

  20. The Hubble Space Telescope Medium Deep Survey Cluster Sample: Methodology and Data

    Science.gov (United States)

    Ostrander, E. J.; Nichol, R. C.; Ratnatunga, K. U.; Griffiths, R. E.

    1998-12-01

    We present a new, objectively selected, sample of galaxy overdensities detected in the Hubble Space Telescope Medium Deep Survey (MDS). These clusters/groups were found using an automated procedure that involved searching for statistically significant galaxy overdensities. The contrast of the clusters against the field galaxy population is increased when morphological data are used to search around bulge-dominated galaxies. In total, we present 92 overdensities above a probability threshold of 99.5%. We show, via extensive Monte Carlo simulations, that at least 60% of these overdensities are likely to be real clusters and groups and not random line-of-sight superpositions of galaxies. For each overdensity in the MDS cluster sample, we provide a richness and the average of the bulge-to-total ratio of galaxies within each system. This MDS cluster sample potentially contains some of the most distant clusters/groups ever detected, with about 25% of the overdensities having estimated redshifts z > ~0.9. We have made this sample publicly available to facilitate spectroscopic confirmation of these clusters and help more detailed studies of cluster and galaxy evolution. We also report the serendipitous discovery of a new cluster close on the sky to the rich optical cluster Cl l0016+16 at z = 0.546. This new overdensity, HST 001831+16208, may be coincident with both an X-ray source and a radio source. HST 001831+16208 is the third cluster/group discovered near to Cl 0016+16 and appears to strengthen the claims of Connolly et al. of superclustering at high redshift.

  1. Distance Education in Turkey

    Directory of Open Access Journals (Sweden)

    Dr. Nursel Selver RUZGAR,

    2004-04-01

    Full Text Available Distance Education in Turkey Assistant Professor Dr. Nursel Selver RUZGAR Technical Education Faculty Marmara University, TURKEY ABSTRACT Many countries of the world are using distance education with various ways, by internet, by post and by TV. In this work, development of distance education in Turkey has been presented from the beginning. After discussing types and applications for different levels of distance education in Turkey, the distance education was given in the cultural aspect of the view. Then, in order to create the tendencies and thoughts of graduates of Higher Education Institutions and Distance Education Institutions about being competitors in job markets, sufficiency of education level, advantages for education system, continuing education in different Institutions, a face-to-face survey was applied to 1284 graduates, 958 from Higher Education Institutions and 326 from Distance Education Institutions. The results were evaluated and discussed. In the last part of this work, suggestions to become widespread and improve the distance education in the country were made.

  2. Snowball sampling by mail: application to a survey of smokers in the general population.

    Science.gov (United States)

    Etter, J F; Perneger, T V

    2000-02-01

    In a series of surveys intended for current and former smokers but sent to a random sample of the general population, we asked never smokers and smokers who did not wish to participate to transmit the questionnaire to any ever smoker they knew. We compared participants who received the questionnaire directly from us (original participants) to participants who received it from an addressee (secondary participants). Questionnaires on smoking were mailed to 3300 residents of Geneva (Switzerland) in 1997, and returned by 1167 people (35%). The final sample consisted of similar numbers of original participants (n = 578, primary response rate = 18% of total sample, or about 46% of ever smokers) and secondary participants (n = 566). Original participants were 1.7 years older than secondary participants (P = 0.03) and were more likely to be men (50% versus 43%, P = 0.009). Proportions of current smokers, stages of change, confidence in ability to quit smoking, cigarettes per day and attempts to quit smoking were similar in the two groups. Secondary participants had lower self-efficacy scores (-0.30 standard deviation (SD) units, P < 0.03), and they derived more pleasure from smoking (+0.25 SD units, P = 0.04). Among ex-smokers, direct participants were less active than secondary participants in coping with the temptation to smoke (-0.58 SD units, P = 0.002). Associations between smoking-related variables were similar in original and secondary participants. Allowing non-eligible addressees to transmit the questionnaire to someone else doubled the response rate, produced moderate bias on some variables only and had no detectable impact on associations between smoking-related variables.

  3. 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

  4. A two-phase sampling design for increasing detections of rare species in occupancy surveys

    Science.gov (United States)

    Pacifici, Krishna; Dorazio, Robert M.; Dorazio, Michael J.

    2012-01-01

    1. Occupancy estimation is a commonly used tool in ecological studies owing to the ease at which data can be collected and the large spatial extent that can be covered. One major obstacle to using an occupancy-based approach is the complications associated with designing and implementing an efficient survey. These logistical challenges become magnified when working with rare species when effort can be wasted in areas with none or very few individuals. 2. Here, we develop a two-phase sampling approach that mitigates these problems by using a design that places more effort in areas with higher predicted probability of occurrence. We compare our new sampling design to traditional single-season occupancy estimation under a range of conditions and population characteristics. We develop an intuitive measure of predictive error to compare the two approaches and use simulations to assess the relative accuracy of each approach. 3. Our two-phase approach exhibited lower predictive error rates compared to the traditional single-season approach in highly spatially correlated environments. The difference was greatest when detection probability was high (0·75) regardless of the habitat or sample size. When the true occupancy rate was below 0·4 (0·05-0·4), we found that allocating 25% of the sample to the first phase resulted in the lowest error rates. 4. In the majority of scenarios, the two-phase approach showed lower error rates compared to the traditional single-season approach suggesting our new approach is fairly robust to a broad range of conditions and design factors and merits use under a wide variety of settings. 5. Synthesis and applications. Conservation and management of rare species are a challenging task facing natural resource managers. It is critical for studies involving rare species to efficiently allocate effort and resources as they are usually of a finite nature. We believe our approach provides a framework for optimal allocation of effort while

  5. HIV/AIDS and the long-distance truck drivers in south-west Nigeria: A cross-sectional survey on the knowledge, attitude, risk behaviour and beliefs of truckers

    Directory of Open Access Journals (Sweden)

    Glory O. Atilola

    2010-12-01

    Full Text Available Summary: Objectives: According to the last HIV surveillance survey conducted in 2008, the overall National HIV prevalence in Nigeria stands at 4.6%. Recent studies and estimates by UNAIDS/WHO show higher prevalences in some selected states in Nigeria. The focus of this study is to determine the prevalence, risk behaviour, attitude and knowledge of HIV among long-distance heavy-truckers from a cross-sectional survey conducted in the south-west Nigeria. Methods: Four major truck terminals (devoted to long-distance trips in south western Nigeria were identified. A cross-sectional survey was conducted using a total sample size of 451 truckers who consented to be interviewed. A questionnaire (in English, Hausa and Yoruba languages for data collection on the socio-demographic, risk behaviour, attitude and knowledge of HIV from the truckers was also designed. The multiple logistic regressions analysis was used to assess the association between some selected variables and factors. Results: Only 164 (36.4% participants out of the study population of 451 were tested for HIV (due to limited test facilities and consent and the prevalence of HIV antibodies among the truckers was found to be 2.4% (4/164 with all the infected individuals being within 21–30 years of age. 309 (68.1% of the respondents admitted that they were at risk of contracting HIV while a total of 249 (55.3% admitted that they had more than one sexual partners. In addition, while 392 (86.9% said it was important for them to know their HIV status, 88 (19.5% said that they would commit suicide should they test positive for HIV. Conclusion: Although the HIV prevalence rate observed among the tested participants (2.4% was lower than the overall national prevalence (4.6%, the result calls for concern as it showed that the population of truckers is a potential high risk group in Nigeria. Also, the mobile nature of this high-risk group has made getting HIV/AIDS awareness messages across to them a

  6. Differential efficiencies of dip-net sampling versus sampling surface-floating pupal exuviae in a biodiversity survey of Chironomidae

    Directory of Open Access Journals (Sweden)

    Leonard Charles Ferrington Jr

    2014-12-01

    Full Text Available Relative efficiencies of standard dip-net sampling (SDN versus collections of surface-floating pupal exuviae (SFPE were determined for detecting Chironomidae at catchment and site scales and at subfamily/tribe-, genus- and species-levels based on simultaneous, equal-effort sampling on a monthly basis for one year during a biodiversity assessment of Bear Run Nature Reserve. Results showed SFPE was more efficient than SDN at catchment scales for detecting both genera and species. At site scales, SDN sampling was more efficient for assessment of a first-order site. No consistent pattern, except for better efficiency of SFPE to detect Orthocladiinae genera, was observed at genus-level for two second-order sites. However, SFPE was consistently more efficient at detecting species of Orthocladiinae, Chironomini and Tanytarsini at the second order sites. SFPE was more efficient at detecting both genera and species at two third-order sites. The differential efficiencies of the two methods are concluded to be related to stream order and size, substrate size, flow and water velocity, depth and habitat heterogeneity, and differential ability to discriminate species among pupal exuviae specimens versus larval specimens. Although both approaches are considered necessary for comprehensive biodiversity assessments of Chironomidae, our results suggest that there is an optimal, but different, allocation of sampling effort for detecting Chironomidae across stream orders and at differing spatial and taxonomic scales.Article submitted 13. August 2014, accepted 31. October 2014, published 22. December 2014.

  7. Regional soil erosion assessment based on a sample survey and geostatistics

    Directory of Open Access Journals (Sweden)

    S. Yin

    2018-03-01

    Full Text Available Soil erosion is one of the most significant environmental problems in China. From 2010 to 2012, the fourth national census for soil erosion sampled 32 364 PSUs (Primary Sampling Units, small watersheds with the areas of 0.2–3 km2. Land use and soil erosion controlling factors including rainfall erosivity, soil erodibility, slope length, slope steepness, biological practice, engineering practice, and tillage practice for the PSUs were surveyed, and the soil loss rate for each land use in the PSUs was estimated using an empirical model, the Chinese Soil Loss Equation (CSLE. Though the information collected from the sample units can be aggregated to estimate soil erosion conditions on a large scale; the problem of estimating soil erosion condition on a regional scale has not been addressed well. The aim of this study is to introduce a new model-based regional soil erosion assessment method combining a sample survey and geostatistics. We compared seven spatial interpolation models based on the bivariate penalized spline over triangulation (BPST method to generate a regional soil erosion assessment from the PSUs. Shaanxi Province (3116 PSUs in China was selected for the comparison and assessment as it is one of the areas with the most serious erosion problem. Ten-fold cross-validation based on the PSU data showed the model assisted by the land use, rainfall erosivity factor (R, soil erodibility factor (K, slope steepness factor (S, and slope length factor (L derived from a 1 : 10 000 topography map is the best one, with the model efficiency coefficient (ME being 0.75 and the MSE being 55.8 % of that for the model assisted by the land use alone. Among four erosion factors as the covariates, the S factor contributed the most information, followed by K and L factors, and R factor made almost no contribution to the spatial estimation of soil loss. The LS factor derived from 30 or 90 m Shuttle Radar Topography Mission

  8. Regional soil erosion assessment based on a sample survey and geostatistics

    Science.gov (United States)

    Yin, Shuiqing; Zhu, Zhengyuan; Wang, Li; Liu, Baoyuan; Xie, Yun; Wang, Guannan; Li, Yishan

    2018-03-01

    Soil erosion is one of the most significant environmental problems in China. From 2010 to 2012, the fourth national census for soil erosion sampled 32 364 PSUs (Primary Sampling Units, small watersheds) with the areas of 0.2-3 km2. Land use and soil erosion controlling factors including rainfall erosivity, soil erodibility, slope length, slope steepness, biological practice, engineering practice, and tillage practice for the PSUs were surveyed, and the soil loss rate for each land use in the PSUs was estimated using an empirical model, the Chinese Soil Loss Equation (CSLE). Though the information collected from the sample units can be aggregated to estimate soil erosion conditions on a large scale; the problem of estimating soil erosion condition on a regional scale has not been addressed well. The aim of this study is to introduce a new model-based regional soil erosion assessment method combining a sample survey and geostatistics. We compared seven spatial interpolation models based on the bivariate penalized spline over triangulation (BPST) method to generate a regional soil erosion assessment from the PSUs. Shaanxi Province (3116 PSUs) in China was selected for the comparison and assessment as it is one of the areas with the most serious erosion problem. Ten-fold cross-validation based on the PSU data showed the model assisted by the land use, rainfall erosivity factor (R), soil erodibility factor (K), slope steepness factor (S), and slope length factor (L) derived from a 1 : 10 000 topography map is the best one, with the model efficiency coefficient (ME) being 0.75 and the MSE being 55.8 % of that for the model assisted by the land use alone. Among four erosion factors as the covariates, the S factor contributed the most information, followed by K and L factors, and R factor made almost no contribution to the spatial estimation of soil loss. The LS factor derived from 30 or 90 m Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) data

  9. Male Circumcision and STI Acquisition in Britain: Evidence from a National Probability Sample Survey.

    Directory of Open Access Journals (Sweden)

    Virginia Homfray

    Full Text Available It is well-established that male circumcision reduces acquisition of HIV, herpes simplex virus 2, chancroid, and syphilis. However, the effect on the acquisition of non-ulcerative sexually transmitted infections (STIs remains unclear. We examined the relationship between circumcision and biological measures of three STIs: human papillomavirus (HPV, Chlamydia trachomatis and Mycoplasma genitalium.A probability sample survey of 15,162 men and women aged 16-74 years (including 4,060 men aged 16-44 years was carried out in Britain between 2010 and 2012. Participants completed a computer-assisted personal interview, including a computer-assisted self-interview, which asked about experience of STI diagnoses, and circumcision. Additionally, 1,850 urine samples from sexually-experienced men aged 16-44 years were collected and tested for STIs. Multivariable logistic regression was used to calculate adjusted odds ratios (AOR to quantify associations between circumcision and i self-reporting any STI diagnosis and ii presence of STIs in urine, in men aged 16-44 years, adjusting for key socio-demographic and sexual behavioural factors.The prevalence of circumcision in sexually-experienced men aged 16-44 years was 17.4% (95%CI 16.0-19.0. There was no association between circumcision and reporting any previous STI diagnoses, and specifically previous chlamydia or genital warts. However, circumcised men were less likely to have any HPV type (AOR 0.26, 95% confidence interval (CI 0.13-0.50 including high-risk HPV types (HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and/or 68 (AOR 0.14, 95% CI 0.05-0.40 detected in urine.Circumcised men had reduced odds of HPV detection in urine. These findings have implications for improving the precision of models of STI transmission in populations with different circumcision prevalence and in designing interventions to reduce STI acquisition.

  10. Survey Response Styles, Acculturation, and Culture Among a Sample of Mexican American Adults.

    Science.gov (United States)

    Davis, Rachel E; Resnicow, Ken; Couper, Mick P

    2011-10-01

    A number of studies have investigated use of extreme (ERS) and acquiescent (ARS) response styles across cultural groups. However, due to within-group heterogeneity, it is important to also examine use of response styles, acculturation, and endorsement of cultural variables at the individual level. This study explores relationships between acculturation, six Mexican cultural factors, ERS, and ARS among a sample of 288 Mexican American telephone survey respondents. Three aspects of acculturation were assessed: Spanish use, the importance of preserving Mexican culture, and interaction with Mexican Americans versus Anglos. These variables were hypothesized to positively associate with ERS and ARS. Participants with higher Spanish use did utilize more ERS and ARS; however, value for preserving Mexican culture and interaction with Mexican Americans were not associated with response style use. In analyses of cultural factors, endorsement of familismo and simpatia were related to more frequent ERS and ARS, machismo was associated with lower ERS among men, and la mujer was related to higher ERS among women. Caballerismo was marginally associated with utilization of ERS among men. No association was found between la mujer abnegada and ERS among women. Relationships between male gender roles and ARS were nonsignificant. Relationships between female gender roles and ARS were mixed but trended in the positive direction. Overall, these findings suggest that Mexican American respondents vary in their use of response styles by acculturation and cultural factors. This usage may be specifically influenced by participants' valuing of and engagement with constructs directly associated with social behavior.

  11. A SYSTEMATIC SEARCH FOR MASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY SPECTROSCOPIC SAMPLE

    International Nuclear Information System (INIS)

    Tsalmantza, P.; Decarli, R.; Hogg, David W.; Dotti, M.

    2011-01-01

    We present the results of a systematic search for massive black hole binaries in the Sloan Digital Sky Survey (SDSS) spectroscopic database. We focus on bound binaries, under the assumption that one of the black holes is active. In this framework, the broad lines associated with the accreting black hole are expected to show systematic velocity shifts with respect to the narrow lines, which trace the rest frame of the galaxy. For a sample of 54,586 quasars and 3929 galaxies at redshifts 0.1 < z < 1.5, we brute-force model each spectrum as a mixture of two quasars at two different redshifts. The spectral model is a data-driven dimensionality reduction of the SDSS quasar spectra based on a matrix factorization. We identified 32 objects with peculiar spectra. Nine of them can be interpreted as black hole binaries. This doubles the number of known black hole binary candidates. We also report on the discovery of a new class of extreme double-peaked emitters with exceptionally broad and faint Balmer lines. For all the interesting sources, we present detailed analysis of the spectra and discuss possible interpretations.

  12. Adaptive geostatistical sampling enables efficient identification of malaria hotspots in repeated cross-sectional surveys in rural Malawi.

    Directory of Open Access Journals (Sweden)

    Alinune N Kabaghe

    Full Text Available In the context of malaria elimination, interventions will need to target high burden areas to further reduce transmission. Current tools to monitor and report disease burden lack the capacity to continuously detect fine-scale spatial and temporal variations of disease distribution exhibited by malaria. These tools use random sampling techniques that are inefficient for capturing underlying heterogeneity while health facility data in resource-limited settings are inaccurate. Continuous community surveys of malaria burden provide real-time results of local spatio-temporal variation. Adaptive geostatistical design (AGD improves prediction of outcome of interest compared to current random sampling techniques. We present findings of continuous malaria prevalence surveys using an adaptive sampling design.We conducted repeated cross sectional surveys guided by an adaptive sampling design to monitor the prevalence of malaria parasitaemia and anaemia in children below five years old in the communities living around Majete Wildlife Reserve in Chikwawa district, Southern Malawi. AGD sampling uses previously collected data to sample new locations of high prediction variance or, where prediction exceeds a set threshold. We fitted a geostatistical model to predict malaria prevalence in the area.We conducted five rounds of sampling, and tested 876 children aged 6-59 months from 1377 households over a 12-month period. Malaria prevalence prediction maps showed spatial heterogeneity and presence of hotspots-where predicted malaria prevalence was above 30%; predictors of malaria included age, socio-economic status and ownership of insecticide-treated mosquito nets.Continuous malaria prevalence surveys using adaptive sampling increased malaria prevalence prediction accuracy. Results from the surveys were readily available after data collection. The tool can assist local managers to target malaria control interventions in areas with the greatest health impact and is

  13. Nonprobability Web Surveys to Measure Sexual Behaviors and Attitudes in the General Population: A Comparison With a Probability Sample Interview Survey

    Science.gov (United States)

    Burkill, Sarah; Couper, Mick P; Conrad, Frederick; Clifton, Soazig; Tanton, Clare; Phelps, Andrew; Datta, Jessica; Mercer, Catherine H; Sonnenberg, Pam; Prah, Philip; Mitchell, Kirstin R; Wellings, Kaye; Johnson, Anne M; Copas, Andrew J

    2014-01-01

    Background Nonprobability Web surveys using volunteer panels can provide a relatively cheap and quick alternative to traditional health and epidemiological surveys. However, concerns have been raised about their representativeness. Objective The aim was to compare results from different Web panels with a population-based probability sample survey (n=8969 aged 18-44 years) that used computer-assisted self-interview (CASI) for sensitive behaviors, the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Methods Natsal-3 questions were included on 4 nonprobability Web panel surveys (n=2000 to 2099), 2 using basic quotas based on age and sex, and 2 using modified quotas based on additional variables related to key estimates. Results for sociodemographic characteristics were compared with external benchmarks and for sexual behaviors and opinions with Natsal-3. Odds ratios (ORs) were used to express differences between the benchmark data and each survey for each variable of interest. A summary measure of survey performance was the average absolute OR across variables. Another summary measure was the number of key estimates for which the survey differed significantly (at the 5% level) from the benchmarks. Results For sociodemographic variables, the Web surveys were less representative of the general population than Natsal-3. For example, for men, the average absolute OR for Natsal-3 was 1.14, whereas for the Web surveys the average absolute ORs ranged from 1.86 to 2.30. For all Web surveys, approximately two-thirds of the key estimates of sexual behaviors were different from Natsal-3 and the average absolute ORs ranged from 1.32 to 1.98. Differences were appreciable even for questions asked by CASI in Natsal-3. No single Web survey performed consistently better than any other did. Modified quotas slightly improved results for men, but not for women. Conclusions Consistent with studies from other countries on less sensitive topics, volunteer Web

  14. Assessing distances and consistency of kinematics in Gaia/TGAS

    Science.gov (United States)

    Schönrich, Ralph; Aumer, Michael

    2017-12-01

    We apply the statistical methods by Schönrich, Binney & Asplund to assess the quality of distances and kinematics in the Radial Velocity Experiment (RAVE)-Tycho-Gaia Astrometric Solution (TGAS) and Large Sky Area Multiobject Fiber Spectroscopic Telescope (LAMOST)-TGAS samples of Solar neighbourhood stars. These methods yield a nominal distance accuracy of 1-2 per cent. Other than common tests on parallax accuracy, they directly test distance estimations including the effects of distance priors. We show how to construct these priors including the survey selection functions (SSFs) directly from the data. We demonstrate that neglecting the SSFs causes severe distance biases. Due to the decline of the SSFs in distance, the simple 1/parallax estimate only mildly underestimates distances. We test the accuracy of measured line-of-sight velocities (vlos) by binning the samples in the nominal vlos uncertainties. We find: (i) the LAMOST vlos have a ∼-5 km s-1 offset; (ii) the average LAMOST measurement error for vlos is ∼7 km s-1, significantly smaller than, and nearly uncorrelated with the nominal LAMOST estimates. The RAVE sample shows either a moderate distance underestimate, or an unaccounted source of vlos dispersion (e∥) from measurement errors and binary stars. For a subsample of suspected binary stars in RAVE, our methods indicate significant distance underestimates. Separating a sample in metallicity or kinematics to select thick-disc/halo stars, discriminates between distance bias and e∥. For LAMOST, this separation yields consistency with pure vlos measurement errors. We find an anomaly near longitude l ∼ (300 ± 60)° and distance s ∼ (0.32 ± 0.03) kpc on both sides of the galactic plane, which could be explained by either a localized distance error or a breathing mode.

  15. Can smartphones measure momentary quality of life and participation? A proof of concept using experience sampling surveys with university students.

    Science.gov (United States)

    Liddle, Jacki; Wishink, Anna; Springfield, Liz; Gustafsson, Louise; Ireland, David; Silburn, Peter

    2017-08-01

    Understanding quality of life and participation is a key aspect of occupational therapy research. The use of smartphones to deliver experience-sampling surveys may provide an accessible way to monitor these outcomes. This study used smartphone-based experience sampling methods (ESM) to investigate factors influencing momentary quality of life (mQOL) of university students. A convenience sample of students at an Australian university participated. Using a custom smartphone application, ESM surveys were sent six to eight times, every second day, over a week. Participants indicated their mQOL, occupational participation, occupational enjoyment, social context and location via surveys and provided demographic and health information in a single self-report questionnaire. The relationship between mQOL and variables was analysed at the survey level using logistic regression. Forty students completed 391 surveys. Higher mQOL was significantly related to participation in productive occupations (z = 3.48; P = 0.001), moderate (z = 4.00; P sample, analysing at the individual level, and using ESM in conjunction with other methodologies is recommended. © 2017 Occupational Therapy Australia.

  16. The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: anisotropic Baryon Acoustic Oscillations measurements in Fourier-space with optimal redshift weights

    Science.gov (United States)

    Wang, Dandan; Zhao, Gong-Bo; Wang, Yuting; Percival, Will J.; Ruggeri, Rossana; Zhu, Fangzhou; Tojeiro, Rita; Myers, Adam D.; Chuang, Chia-Hsun; Baumgarten, Falk; Zhao, Cheng; Gil-Marín, Héctor; Ross, Ashley J.; Burtin, Etienne; Zarrouk, Pauline; Bautista, Julian; Brinkmann, Jonathan; Dawson, Kyle; Brownstein, Joel R.; de la Macorra, Axel; Schneider, Donald P.; Shafieloo, Arman

    2018-06-01

    We present a measurement of the anisotropic and isotropic Baryon Acoustic Oscillations (BAO) from the extended Baryon Oscillation Spectroscopic Survey Data Release 14 quasar sample with optimal redshift weights. Applying the redshift weights improves the constraint on the BAO dilation parameter α(zeff) by 17 per cent. We reconstruct the evolution history of the BAO distance indicators in the redshift range of 0.8 < z < 2.2. This paper is part of a set that analyses the eBOSS DR14 quasar sample.

  17. Paediatric palliative home care in areas of Germany with low population density and long distances: a questionnaire survey with general paediatricians

    Directory of Open Access Journals (Sweden)

    Kremeike Kerstin

    2012-09-01

    Full Text Available Abstract Background In 2007, the patient’s right to specialised palliative home care became law in Germany. However, childhood palliative care in territorial states with low patient numbers and long distances requires adapted models to ensure an area-wide maintenance. Actually, general paediatricians are the basic care providers for children and adolescents. They also provide home care. The aim of this study was to improve the knowledge about general paediatrician’s involvement in and contribution to palliative care in children. Findings To evaluate the current status of palliative home care provided by general paediatricians and their cooperation with other paediatric palliative care providers, a questionnaire survey was disseminated to general paediatricians in Lower Saxony, a German federal state with nearly eight million inhabitants and a predominantly rural infrastructure. Data analysis was descriptive. One hundred forty one of 157 included general paediatricians completed the questionnaire (response rate: 89.8%. A total of 792 children and adolescents suffering from life-limiting conditions were cared for by these general paediatricians in 2008. Severe cerebral palsy was the most prevalent diagnosis. Eighty-nine per cent of the general paediatricians stated that they had professional experience with paediatric palliative care. Collaboration of general paediatricians and other palliative care providers was stated as not well developed. The support by a specialised team including 24-hour on-call duty and the intensification of educational programs were emphasised. Conclusions The current regional infrastructure of palliative home care in Lower Saxony can benefit from the establishment of a coordinated network of palliative home care providers.

  18. An internet-based survey in Japan concerning social distance and stigmatization toward the mentally ill among doctors, nurses, pharmacists, and the general public.

    Science.gov (United States)

    Fujii, Tomoo; Hanya, Manako; Kishi, Masanori; Kondo, Yuki; Cates, Marshall E; Kamei, Hiroyuki

    2018-05-28

    Stigma associated with psychiatric disorders tends to be manifested as negative attitudes or behavior toward the mentally ill. It has negative influences, such as leading to difficulty in establishing trust-based relationships and interfering with medical treatment. In order to reduce such stigma, it is necessary to clarify its extent and characteristics in healthcare professionals. Considering this, an Internet-based questionnaire survey was conducted, involving doctors (n = 186), nurses (n = 161), and pharmacists (n = 192) in comparison with the general public (n = 331), and using the Whatley Social Distance Scale (WSDS) and Index of Attitudes toward the Mentally Ill (IATM) as stigma-related indices. Median total WSDS scores and interquartile range were as follows: doctors: 15.5(12.0-18.0), nurses: 14.0(12.0-16.5), pharmacists: 15.0(13.0-17.0), and the general public: 16.0(13.0-18.0). Similarly, median IATM scores were as follows: doctors: 39.0(36.0-42.0), nurses: 39.0(37.0-43.0), pharmacists: 40.0(36.0-42.0), and the general public: 37.0(33.0-41.0). IATM scores were significantly higher in the professional groups than the general public group. Both healthcare professionals and the general public with prior exposure to mental illness were more favorable attitudes toward the mentally ill. Especially among healthcare professionals, they working in psychiatric departments were more favorable attitudes. These results suggest that the stigma of healthcare professionals toward the mentally ill was shown to have a smaller and relatively favorable attitude than that of the general public. In order to correct the stigma it was suggested that a good contact experience with the patient such as work and training in psychiatry is effective. Copyright © 2018. Published by Elsevier B.V.

  19. A Systematic Mid-Infrared Survey of A Sample of Tidal Disruption Events Discovered by ZTF

    Science.gov (United States)

    Yan, Lin; Van, Sjoert; Kulkarni, Shri; Kasliwal, Mansi; Gezari, Suvi; Cenko, Brad; Blagorodnova, Nadia; Hung, Tiara

    2017-12-01

    Zwicky Transient Facility (ZTF) saw its first light (press release on Nov 14, 2017) and is currently in the commissioning phase. The science operation is scheduled to start on Feb 1, 2018. Based on the data from Palomar Transient Factory (PTF), ZTF is expected to discover 30 new tidal disruption events (TDE) in the centers of galaxies containing supermassive blackholes. TDEs are rare transient events, and have only been discovered in recent years by large area transient surveys. Observations of optically discovered TDEs appear to show common characteristics, including blackbody temperatures of a few 10,000K, derived bolometric peak luminosities of several 10^43 - 10^44 erg/s, and photospheric radius of 10^15 - 10^16 cm. These properties are in conflict with the classic TDE model predictions, which suggest an order of magnitude higher temperature and peak luminosity. One proposed explanation is the possible existence of a reprocessing gas layer which absorbs X-ray, UV/optical photons and produces a cooler spectral energy distribution (SED). So far, there are only two published mid-IR light curves of TDEs, each with two epochal data. To solve this mystery, we require higher cadence Spitzer observations of a sample of uniformly selected TDEs. Next year is the only opportunity to obtain the critical observations because Spitzer is expected to operate only to March 2019. We request 24.1 hours of Spitzer time to observe 7 ZTF TDEs. This will produce a unique legacy dataset for many future studies of physics of TDEs.

  20. Dream characteristics in a Brazilian sample: an online survey focusing on lucid dreaming

    Science.gov (United States)

    Mota-Rolim, Sérgio A.; Targino, Zé H.; Souza, Bryan C.; Blanco, Wilfredo; Araujo, John F.; Ribeiro, Sidarta

    2013-01-01

    During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD), subjects know that they are dreaming, and may control oneiric content. Dreaming and LD features have been studied in North Americans, Europeans and Asians, but not among Brazilians, the largest population in Latin America. Here we investigated dreams and LD characteristics in a Brazilian sample (n = 3,427; median age = 25 years) through an online survey. The subjects reported recalling dreams at least once a week (76%), and that dreams typically depicted actions (93%), known people (92%), sounds/voices (78%), and colored images (76%). The oneiric content was associated with plans for the upcoming days (37%), memories of the previous day (13%), or unrelated to the dreamer (30%). Nightmares usually depicted anxiety/fear (65%), being stalked (48%), or other unpleasant sensations (47%). These data corroborate Freudian notion of day residue in dreams, and suggest that dreams and nightmares are simulations of life situations that are related to our psychobiological integrity. Regarding LD, we observed that 77% of the subjects experienced LD at least once in life (44% up to 10 episodes ever), and for 48% LD subjectively lasted less than 1 min. LD frequency correlated weakly with dream recall frequency (r = 0.20, p < 0.01), and LD control was rare (29%). LD occurrence was facilitated when subjects did not need to wake up early (38%), a situation that increases rapid eye movement sleep (REMS) duration, or when subjects were under stress (30%), which increases REMS transitions into waking. These results indicate that LD is relatively ubiquitous but rare, unstable, difficult to control, and facilitated by increases in REMS duration and transitions to wake state. Together with LD incidence in USA, Europe and Asia, our data from Latin America strengthen the notion that LD

  1. Dream characteristics in a Brazilian sample: an online survey focusing on lucid dreaming

    Directory of Open Access Journals (Sweden)

    Sérgio Arthuro Mota-Rolim

    2013-12-01

    Full Text Available During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD, subjects know that they are dreaming, and may control oneiric content. Dreaming and LD features have been studied in North Americans, Europeans and Asians, but not among Brazilians, the largest population in Latin America. Here we investigated dreams and LD characteristics in a Brazilian sample (n=3,427; median age=25 years through an online survey. The subjects reported recalling dreams at least once a week (76%. Dreams typically depicted actions (93%, known people (92%, sounds/voices (78%, and colored images (76%. The oneiric content was associated with plans for the upcoming days (37%, memories of the previous day (13%, or unrelated to the dreamer (30%. Nightmares usually depicted anxiety/fear (65%, being stalked (48%, or other unpleasant sensations (47%. These data corroborate Freudian notion of day residue, and suggest that dreams are simulations of life situations that are related to our psychobiological integrity. Regarding LD, we observed that 77% of the subjects experienced LD at least once in life (44% up to 10 episodes ever, and for 48% LD subjectively lasted less than 1 minute. LD frequency correlated weakly with dream recall frequency (r=0.20, p<0.01, and LD control was rare (29%. LD occurrence was facilitated when subjects did not need to wake up early (38%, a situation that increases REMS duration, or when subjects were under stress (30%, which increases REMS transitions into waking. These results indicate that LD is a relatively ubiquitous but not frequent state, being unstable, difficult to control, and facilitated by increases in REMS duration and transitions to wake state. Together with LD incidence in USA, Europe and Asia, our data from Latin America strengthen the notion that LD is a general phenomenon of the human

  2. Dream characteristics in a Brazilian sample: an online survey focusing on lucid dreaming.

    Science.gov (United States)

    Mota-Rolim, Sérgio A; Targino, Zé H; Souza, Bryan C; Blanco, Wilfredo; Araujo, John F; Ribeiro, Sidarta

    2013-01-01

    During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD), subjects know that they are dreaming, and may control oneiric content. Dreaming and LD features have been studied in North Americans, Europeans and Asians, but not among Brazilians, the largest population in Latin America. Here we investigated dreams and LD characteristics in a Brazilian sample (n = 3,427; median age = 25 years) through an online survey. The subjects reported recalling dreams at least once a week (76%), and that dreams typically depicted actions (93%), known people (92%), sounds/voices (78%), and colored images (76%). The oneiric content was associated with plans for the upcoming days (37%), memories of the previous day (13%), or unrelated to the dreamer (30%). Nightmares usually depicted anxiety/fear (65%), being stalked (48%), or other unpleasant sensations (47%). These data corroborate Freudian notion of day residue in dreams, and suggest that dreams and nightmares are simulations of life situations that are related to our psychobiological integrity. Regarding LD, we observed that 77% of the subjects experienced LD at least once in life (44% up to 10 episodes ever), and for 48% LD subjectively lasted less than 1 min. LD frequency correlated weakly with dream recall frequency (r = 0.20, p < 0.01), and LD control was rare (29%). LD occurrence was facilitated when subjects did not need to wake up early (38%), a situation that increases rapid eye movement sleep (REMS) duration, or when subjects were under stress (30%), which increases REMS transitions into waking. These results indicate that LD is relatively ubiquitous but rare, unstable, difficult to control, and facilitated by increases in REMS duration and transitions to wake state. Together with LD incidence in USA, Europe and Asia, our data from Latin America strengthen the notion that LD

  3. THE ELM SURVEY. I. A COMPLETE SAMPLE OF EXTREMELY LOW-MASS WHITE DWARFS

    International Nuclear Information System (INIS)

    Brown, Warren R.; Kilic, Mukremin; Kenyon, Scott J.; Prieto, Carlos Allende

    2010-01-01

    We analyze radial velocity observations of the 12 extremely low-mass (ELM), with ≤0.25 M sun , white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binaries with orbital periods shorter than 14 hr; the one non-variable WD is possibly a pole-on system among our non-kinematically selected targets. Our sample is unique: it is complete in a well-defined range of apparent magnitude and color. The orbital mass functions imply that the unseen companions are most likely other WDs, although neutron star companions cannot be excluded. Six of the eleven systems with orbital solutions will merge within a Hubble time due to the loss of angular momentum through gravitational wave radiation. The quickest merger is J0923+3028, a g = 15.7 ELM WD binary with a 1.08 hr orbital period and a ≤130 Myr merger time. The chance of a supernova Ia event among our ELM WDs is only 1%-7%, however. Three binary systems (J0755+4906, J1233+1602, and J2119-0018) have extreme mass ratios and will most likely form stable mass-transfer AM CVn systems. Two of these objects, SDSS J1233+1602 and J2119-0018, are the lowest surface gravity WDs ever found; both show Ca II absorption likely from accretion of circumbinary material. We predict that at least one of our WDs is an eclipsing detached double WD system, important for constraining helium core WD models.

  4. Spatial pattern corrections and sample sizes for forest density estimates of historical tree surveys

    Science.gov (United States)

    Brice B. Hanberry; Shawn Fraver; Hong S. He; Jian Yang; Dan C. Dey; Brian J. Palik

    2011-01-01

    The U.S. General Land Office land surveys document trees present during European settlement. However, use of these surveys for calculating historical forest density and other derived metrics is limited by uncertainty about the performance of plotless density estimators under a range of conditions. Therefore, we tested two plotless density estimators, developed by...

  5. CALIFA: a diameter-selected sample for an integral field spectroscopy galaxy survey

    Czech Academy of Sciences Publication Activity Database

    Walcher, C.J.; Wisotzki, L.; Bekeraite, S.; Husemann, B.; Iglesias-Paramo, J.; Backsmann, N.; Barrera-Ballesteros, J.; Catalán-Torrecilla, C.; Cortijo-Ferrero, C.; del Olmo, A.; Garcia Lorenzo, B.; Falcon-Barroso, J.; Jílková, J.; Kalinová, V.; Mast, D.; Marino, R.A.; Méndez-Abreu, J.; Pasqual, A.; Sanchez, S.F.; Trager, S.; Zibetti, S.; Aguerri, J.A.L.; Alves, J.; Bland-Hawthorn, J.; Boselli, A.; Castillo-Morales, A.; Fernandes, R.C.; Flores, H.; Galbany, L.; Gallazzi, A.; Garcia-Benito, R.; Gil de Paz, A.; Gonzalez Delgado, R.; Jahnke, K.; Jungwiert, Bruno

    2014-01-01

    Roč. 569, September (2014), A1/1-A1/18 ISSN 0004-6361 Institutional support: RVO:67985815 Keywords : surveys * digital sky survey * active galactic nuclei Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

  6. Manual for the Portable Handheld Neutron Counter (PHNC) for Neutron Survey and the Measurement of Plutonium Samples

    International Nuclear Information System (INIS)

    Menlove, H.O.

    2005-01-01

    We have designed a portable neutron detector for passive neutron scanning measurement and coincidence counting of bulk samples of plutonium. The counter will be used for neutron survey applications as well as the measurement of plutonium samples for portable applications. The detector uses advanced design 3 He tubes to increase the efficiency and battery operated shift register electronics. This report describes the hardware, performance, and calibration for the system

  7. Distance learning

    Directory of Open Access Journals (Sweden)

    Katarina Pucelj

    2006-12-01

    Full Text Available I would like to underline the role and importance of knowledge, which is acquired by individuals as a result of a learning process and experience. I have established that a form of learning, such as distance learning definitely contributes to a higher learning quality and leads to innovative, dynamic and knowledgebased society. Knowledge and skills enable individuals to cope with and manage changes, solve problems and also create new knowledge. Traditional learning practices face new circumstances, new and modern technologies appear, which enable quick and quality-oriented knowledge implementation. The centre of learning process at distance learning is to increase the quality of life of citizens, their competitiveness on the workforce market and ensure higher economic growth. Intellectual capital is the one, which represents the biggest capital of each society and knowledge is the key factor for succes of everybody, who are fully aware of this. Flexibility, openness and willingness of people to follow new IT solutions form suitable environment for developing and deciding to take up distance learning.

  8. Statistical properties of mean stand biomass estimators in a LIDAR-based double sampling forest survey design.

    Science.gov (United States)

    H.E. Anderson; J. Breidenbach

    2007-01-01

    Airborne laser scanning (LIDAR) can be a valuable tool in double-sampling forest survey designs. LIDAR-derived forest structure metrics are often highly correlated with important forest inventory variables, such as mean stand biomass, and LIDAR-based synthetic regression estimators have the potential to be highly efficient compared to single-stage estimators, which...

  9. Off-road sampling reveals a different grassland bird community than roadside sampling: implications for survey design and estimates to guide conservation

    Directory of Open Access Journals (Sweden)

    Troy I. Wellicome

    2014-06-01

    concern. Our results highlight the need to develop appropriate corrections for bias in estimates derived from roadside sampling, and the need to design surveys that sample bird communities across a more representative cross-section of the landscape, both near and far from roads.

  10. The outlier sample effects on multivariate statistical data processing geochemical stream sediment survey (Moghangegh region, North West of Iran)

    International Nuclear Information System (INIS)

    Ghanbari, Y.; Habibnia, A.; Memar, A.

    2009-01-01

    In geochemical stream sediment surveys in Moghangegh Region in north west of Iran, sheet 1:50,000, 152 samples were collected and after the analyze and processing of data, it revealed that Yb, Sc, Ni, Li, Eu, Cd, Co, as contents in one sample is far higher than other samples. After detecting this sample as an outlier sample, the effect of this sample on multivariate statistical data processing for destructive effects of outlier sample in geochemical exploration was investigated. Pearson and Spear man correlation coefficient methods and cluster analysis were used for multivariate studies and the scatter plot of some elements together the regression profiles are given in case of 152 and 151 samples and the results are compared. After investigation of multivariate statistical data processing results, it was realized that results of existence of outlier samples may appear as the following relations between elements: - true relation between two elements, which have no outlier frequency in the outlier sample. - false relation between two elements which one of them has outlier frequency in the outlier sample. - complete false relation between two elements which both have outlier frequency in the outlier sample

  11. Redshifts for a sample of fainter galaxies in the first CfA survey slice

    Science.gov (United States)

    Thorstensen, J. R.; Wegner, G. A.; Hamwey, R.; Boley, F.; Geller, M. J.

    1989-01-01

    Redshifts were measured for 93 of the 94 galaxies in the Zwicky-Nilson merged catalog with the value of m(B/01) between 15.5 and 15.7 and with right ascension alpha between 8(h) and 17(h) and declination delta between 29 and 30 deg. This region is within the one covered by the first slice of the CfA (Center for Astrophysics) survey. The galaxies reinforce features already visible in the earlier survey.

  12. Digital Learning Compass: Distance Education State Almanac 2017. Nebraska

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Nebraska. The sample for this analysis is comprised of all active, degree-granting…

  13. Digital Learning Compass: Distance Education State Almanac 2017. Massachusetts

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Massachusetts. The sample for this analysis is comprised of all active, degree-granting…

  14. Digital Learning Compass: Distance Education State Almanac 2017. Georgia

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Georgia. The sample for this analysis is comprised of all active, degree-granting…

  15. Digital Learning Compass: Distance Education State Almanac 2017. Wyoming

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Wyoming. The sample for this analysis is comprised of all active, degree-granting…

  16. Digital Learning Compass: Distance Education State Almanac 2017. Tennessee

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Tennessee. The sample for this analysis is comprised of all active, degree-granting…

  17. Digital Learning Compass: Distance Education State Almanac 2017. South Carolina

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of South Carolina. The sample for this analysis is comprised of all active, degree-granting…

  18. Digital Learning Compass: Distance Education State Almanac 2017. New Mexico

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of New Mexico. The sample for this analysis is comprised of all active, degree-granting…

  19. Digital Learning Compass: Distance Education State Almanac 2017. Oklahoma

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Oklahoma. The sample for this analysis is comprised of all active, degree-granting…

  20. Digital Learning Compass: Distance Education State Almanac 2017. Texas

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Texas. The sample for this analysis is comprised of all active, degree-granting…

  1. Digital Learning Compass: Distance Education State Almanac 2017. Montana

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Montana. The sample for this analysis is comprised of all active, degree-granting…

  2. Digital Learning Compass: Distance Education State Almanac 2017. Kentucky

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Kentucky. The sample for this analysis is comprised of all active, degree-granting…

  3. Digital Learning Compass: Distance Education State Almanac 2017. New York

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of New York. The sample for this analysis is comprised of all active, degree-granting…

  4. Digital Learning Compass: Distance Education State Almanac 2017. Vermont

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Vermont. The sample for this analysis is comprised of all active, degree-granting…

  5. Digital Learning Compass: Distance Education State Almanac 2017. Illinois

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Illinois. The sample for this analysis is comprised of all active, degree-granting…

  6. Digital Learning Compass: Distance Education State Almanac 2017. Virginia

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Virginia. The sample for this analysis is comprised of all active, degree-granting…

  7. Digital Learning Compass: Distance Education State Almanac 2017. North Dakota

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of North Dakota. The sample for this analysis is comprised of all active, degree-granting…

  8. Digital Learning Compass: Distance Education State Almanac 2017. Arkansas

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Arkansas . The sample for this analysis is comprised of all active, degree-granting…

  9. Digital Learning Compass: Distance Education State Almanac 2017. Washington

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Washington. The sample for this analysis is comprised of all active, degree-granting…

  10. Digital Learning Compass: Distance Education State Almanac 2017. Colorado

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Colorado. The sample for this analysis is comprised of all active, degree-granting…

  11. Digital Learning Compass: Distance Education State Almanac 2017. Louisiana

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Louisiana. The sample for this analysis is comprised of all active, degree-granting…

  12. Digital Learning Compass: Distance Education State Almanac 2017. West Virginia

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of West Virginia. The sample for this analysis is comprised of all active, degree-granting…

  13. Digital Learning Compass: Distance Education State Almanac 2017. Oregon

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Oregon. The sample for this analysis is comprised of all active, degree-granting…

  14. Digital Learning Compass: Distance Education State Almanac 2017. Pennsylvania

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Pennsylvania. The sample for this analysis is comprised of all active, degree-granting…

  15. Digital Learning Compass: Distance Education State Almanac 2017. Maryland

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Maryland. The sample for this analysis is comprised of all active, degree-granting…

  16. Digital Learning Compass: Distance Education State Almanac 2017. Alabama

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Alabama. The sample for this analysis is comprised of all active, degree-granting…

  17. Digital Learning Compass: Distance Education State Almanac 2017. Indiana

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Indiana. The sample for this analysis is comprised of all active, degree-granting…

  18. Digital Learning Compass: Distance Education State Almanac 2017. Mississippi

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Mississippi. The sample for this analysis is comprised of all active, degree-granting…

  19. Digital Learning Compass: Distance Education State Almanac 2017. California

    Science.gov (United States)

    Seaman, Julia A.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of California. The sample for this analysis is comprised of all active, degree-granting…

  20. Digital Learning Compass: Distance Education State Almanac 2017. Ohio

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Ohio. The sample for this analysis is comprised of all active, degree-granting…

  1. Digital Learning Compass: Distance Education State Almanac 2017. New Jersey

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of New Jersey. The sample for this analysis is comprised of all active, degree-granting…

  2. Digital Learning Compass: Distance Education State Almanac 2017. Minnesota

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Minnesota. The sample for this analysis is comprised of all active, degree-granting…

  3. Digital Learning Compass: Distance Education State Almanac 2017. New Hampshire

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of New Hampshire. The sample for this analysis is comprised of all active, degree-granting…

  4. Digital Learning Compass: Distance Education State Almanac 2017. Florida

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Florida. The sample for this analysis is comprised of all active, degree-granting…

  5. Digital Learning Compass: Distance Education State Almanac 2017. Connecticut

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Connecticut. The sample for this analysis is comprised of all active, degree-granting…

  6. Digital Learning Compass: Distance Education State Almanac 2017. South Dakota

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of South Dakota. The sample for this analysis is comprised of all active, degree-granting…

  7. Digital Learning Compass: Distance Education State Almanac 2017. Rhode Island

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Rhode Island. The sample for this analysis is comprised of all active, degree-granting…

  8. Digital Learning Compass: Distance Education State Almanac 2017. Maine

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Maine. The sample for this analysis is comprised of all active, degree-granting…

  9. Digital Learning Compass: Distance Education State Almanac 2017. North Carolina

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of North Carolina. The sample for this analysis is comprised of all active, degree-granting…

  10. Digital Learning Compass: Distance Education State Almanac 2017. Iowa

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Iowa. The sample for this analysis is comprised of all active, degree-granting…

  11. Digital Learning Compass: Distance Education State Almanac 2017. Hawaii

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Hawaii. The sample for this analysis is comprised of all active, degree-granting…

  12. Digital Learning Compass: Distance Education State Almanac 2017. Missouri

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Missouri. The sample for this analysis is comprised of all active, degree-granting…

  13. Digital Learning Compass: Distance Education State Almanac 2017. Arizona

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Arizona . The sample for this analysis is comprised of all active, degree-granting…

  14. Digital Learning Compass: Distance Education State Almanac 2017. Nevada

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Nevada. The sample for this analysis is comprised of all active, degree-granting…

  15. Digital Learning Compass: Distance Education State Almanac 2017. Utah

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Utah. The sample for this analysis is comprised of all active, degree-granting…

  16. Digital Learning Compass: Distance Education State Almanac 2017. Alaska

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Alaska. The sample for this analysis is comprised of all active, degree-granting…

  17. Digital Learning Compass: Distance Education State Almanac 2017. Michigan

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Michigan. The sample for this analysis is comprised of all active, degree-granting…

  18. Digital Learning Compass: Distance Education State Almanac 2017. Idaho

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Idaho. The sample for this analysis is comprised of all active, degree-granting…

  19. Digital Learning Compass: Distance Education State Almanac 2017. Wisconsin

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Wisconsin. The sample for this analysis is comprised of all active, degree-granting…

  20. Digital Learning Compass: Distance Education State Almanac 2017. Delaware

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Delaware. The sample for this analysis is comprised of all active, degree-granting…

  1. Digital Learning Compass: Distance Education State Almanac 2017. Kansas

    Science.gov (United States)

    Seaman, Julia E.; Seaman, Jeff

    2017-01-01

    This brief report uses data collected under the U.S. Department of Education's National Center for Educational Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS) Fall Enrollment survey to highlight distance education data in the state of Kansas. The sample for this analysis is comprised of all active, degree-granting…

  2. Empirically simulated study to compare and validate sampling methods used in aerial surveys of wildlife populations

    NARCIS (Netherlands)

    Khaemba, W.M.; Stein, A.; Rasch, D.; Leeuw, de J.; Georgiadis, N.

    2001-01-01

    This paper compares the distribution, sampling and estimation of abundance for two animal species in an African ecosystem by means of an intensive simulation of the sampling process under a geographical information system (GIS) environment. It focuses on systematic and random sampling designs,

  3. Sampling in health geography: reconciling geographical objectives and probabilistic methods. An example of a health survey in Vientiane (Lao PDR

    Directory of Open Access Journals (Sweden)

    Bochaton Audrey

    2007-06-01

    Full Text Available Abstract Background Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. Methods We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. Application We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. Conclusion This paper describes the conceptual reasoning behind

  4. Sampling in health geography: reconciling geographical objectives and probabilistic methods. An example of a health survey in Vientiane (Lao PDR).

    Science.gov (United States)

    Vallée, Julie; Souris, Marc; Fournet, Florence; Bochaton, Audrey; Mobillion, Virginie; Peyronnie, Karine; Salem, Gérard

    2007-06-01

    Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be

  5. Use of methods for specifying the target difference in randomised controlled trial sample size calculations: Two surveys of trialists' practice.

    Science.gov (United States)

    Cook, Jonathan A; Hislop, Jennifer M; Altman, Doug G; Briggs, Andrew H; Fayers, Peter M; Norrie, John D; Ramsay, Craig R; Harvey, Ian M; Vale, Luke D

    2014-06-01

    the most recent trial, the target difference was usually one viewed as important by a stakeholder group, mostly also viewed as a realistic difference given the interventions under evaluation, and sometimes one that led to an achievable sample size. The response rates achieved were relatively low despite the surveys being short, well presented, and having utilised reminders. Substantial variations in practice exist with awareness, use, and willingness to recommend methods varying substantially. The findings support the view that sample size calculation is a more complex process than would appear to be the case from trial reports and protocols. Guidance on approaches for sample size estimation may increase both awareness and use of appropriate formal methods. © The Author(s), 2014.

  6. The U.S. Geological Survey Geologic Collections Management System (GCMS)—A master catalog and collections management plan for U.S. Geological Survey geologic samples and sample collections

    Science.gov (United States)

    ,

    2015-01-01

    The U.S. Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of earth materials collected by research personnel over the course of its history. In 2006, a Geologic Collections Inventory was conducted within the USGS Geology Discipline to determine the extent and nature of its sample collections, and in 2008, a working group was convened by the USGS National Geologic and Geophysical Data Preservation Program to examine ways in which these collections could be coordinated, cataloged, and made available to researchers both inside and outside the USGS. The charge to this working group was to evaluate the proposition of creating a Geologic Collections Management System (GCMS), a centralized database that would (1) identify all existing USGS geologic collections, regardless of size, (2) create a virtual link among the collections, and (3) provide a way for scientists and other researchers to obtain access to the samples and data in which they are interested. Additionally, the group was instructed to develop criteria for evaluating current collections and to establish an operating plan and set of standard practices for handling, identifying, and managing future sample collections. Policies and procedures promoted by the GCMS would be based on extant best practices established by the National Science Foundation and the Smithsonian Institution. The resulting report—USGS Circular 1410, “The U.S. Geological Survey Geologic Collections Management System (GCMS): A Master Catalog and Collections Management Plan for U.S. Geological Survey Geologic Samples and Sample Collections”—has been developed for sample repositories to be a guide to establishing common practices in the collection, retention, and disposal of geologic research materials throughout the USGS.

  7. Attitudes Toward e-Mental Health Services in a Community Sample of Adults: Online Survey.

    Science.gov (United States)

    March, Sonja; Day, Jamin; Ritchie, Gabrielle; Rowe, Arlen; Gough, Jeffrey; Hall, Tanya; Yuen, Chin Yan Jackie; Donovan, Caroline Leanne; Ireland, Michael

    2018-02-19

    Despite evidence that e-mental health services are effective, consumer preferences still appear to be in favor of face-to-face services. However, the theory of planned behavior (TPB) suggests that cognitive intentions are more proximal to behavior and thus may have a more direct influence on service use. Investigating individual characteristics that influence both preferences and intentions to use e-mental health services is important for better understanding factors that might impede or facilitate the use of these services. This study explores predictors of preferences and intentions to access e-mental health services relative to face-to-face services. Five domains were investigated (demographics, technology factors, personality, psychopathology, and beliefs), identified from previous studies and informed by the Internet interventions model. We expected that more participants would report intentions to use e-mental health services relative to reported preferences for this type of support and that these 5 domains would be significantly associated with both intentions and preferences toward online services. A mixed sample of 308 community members and university students was recruited through social media and the host institution in Australia. Ages ranged between 17 and 68 years, and 82.5% (254/308) were female. Respondents completed an online survey. Chi-square analysis and t tests were used to explore group differences, and logistic regression models were employed to explore factors predicting preferences and intentions. Most respondents (85.7%, 264/308) preferred face-to-face services over e-mental health services. Relative to preferences, a larger proportion of respondents (39.6%, 122/308) endorsed intentions to use e-mental health services if experiencing mental health difficulties in the future. In terms of the 5 predictor domains, 95% CIs of odds ratios (OR) derived from bootstrapped standard errors suggested that prior experience with online services

  8. Planning with Reachable Distances

    KAUST Repository

    Tang, Xinyu; Thomas, Shawna; Amato, Nancy M.

    2009-01-01

    reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot's number of degrees of freedom. In addition

  9. Radiometric survey in sampling areas of Itataia mine ore and radiometric monitoring in Itataia project sites

    International Nuclear Information System (INIS)

    1982-07-01

    This radiometric survey was done by CDTN, in Itataia sites, on July/82 and it aimed fundamentally to evaluate local radiological conditions, as for aspect of occupational radiation protection. Besides of results obtained, this report has informations of general aspects that ought to serve as subsidies for elaboration of radiological protection program of local. (author) [pt

  10. Validity of Suicidality Items from the Youth Risk Behavior Survey in a High School Sample

    Science.gov (United States)

    May, Alexis; Klonsky, E. David

    2011-01-01

    The Youth Risk Behavior Survey (YRBS) is used by the United States Centers for Disease Control to estimate rates of suicidal thoughts and behaviors in adolescents. This study investigated the validity of the YRBS suicidality items by examining their relationship to criterion variables including loneliness, anxiety, depression, substance use, and…

  11. Molecular Biological Characterization of Air Samples: A Survey of Four Strategically Important Regions

    National Research Council Canada - National Science Library

    Francesconi, Stephen

    2003-01-01

    .... In support of this requirement, the Joint Program Office for Biological Defense initiated an aggressive program incorporating the development of air-sampling and agent detecting devices, coined...

  12. Use of Language Sample Analysis by School-Based SLPs: Results of a Nationwide Survey

    Science.gov (United States)

    Pavelko, Stacey L.; Owens, Robert E., Jr.; Ireland, Marie; Hahs-Vaughn, Debbie L.

    2016-01-01

    Purpose: This article examines use of language sample analysis (LSA) by school-based speech-language pathologists (SLPs), including characteristics of language samples, methods of transcription and analysis, barriers to LSA use, and factors affecting LSA use, such as American Speech-Language-Hearing Association certification, number of years'…

  13. Don't spin the pen: two alternative methods for second-stage sampling in urban cluster surveys

    Directory of Open Access Journals (Sweden)

    Rose Angela MC

    2007-06-01

    Full Text Available Abstract In two-stage cluster surveys, the traditional method used in second-stage sampling (in which the first household in a cluster is selected is time-consuming and may result in biased estimates of the indicator of interest. Firstly, a random direction from the center of the cluster is selected, usually by spinning a pen. The houses along that direction are then counted out to the boundary of the cluster, and one is then selected at random to be the first household surveyed. This process favors households towards the center of the cluster, but it could easily be improved. During a recent meningitis vaccination coverage survey in Maradi, Niger, we compared this method of first household selection to two alternatives in urban zones: 1 using a superimposed grid on the map of the cluster area and randomly selecting an intersection; and 2 drawing the perimeter of the cluster area using a Global Positioning System (GPS and randomly selecting one point within the perimeter. Although we only compared a limited number of clusters using each method, we found the sampling grid method to be the fastest and easiest for field survey teams, although it does require a map of the area. Selecting a random GPS point was also found to be a good method, once adequate training can be provided. Spinning the pen and counting households to the boundary was the most complicated and time-consuming. The two methods tested here represent simpler, quicker and potentially more robust alternatives to spinning the pen for cluster surveys in urban areas. However, in rural areas, these alternatives would favor initial household selection from lower density (or even potentially empty areas. Bearing in mind these limitations, as well as available resources and feasibility, investigators should choose the most appropriate method for their particular survey context.

  14. Alcohol Brand Preferences of Underage Youth: Results from a Pilot Survey among a National Sample

    Science.gov (United States)

    Siegel, Michael; DeJong, William; Naimi, Timothy S.; Heeren, Timothy; Rosenbloom, David L.; Ross, Craig; Ostroff, Joshua; Jernigan, David H.

    2011-01-01

    This study is the first investigation to explore the alcohol brand preferences of underage youth via a national survey. We conducted a pilot study of a new, internet-based alcohol brand survey with 108 youth ages 16–20 years who were recruited from an existing panel and had consumed alcohol in the past month. We ascertained respondents’ consumption of each of 380 alcohol brands during the past 30 days, including which brands of alcohol were consumed during heavy drinking episodes. Our findings suggest that, despite the wide variety of alcohol brands consumed by older adolescents in this study, alcohol preferences are concentrated among a relatively small number of brands. Accurate measurements of alcohol brand preferences will enable important new research into the factors that influence youth drinking behavior. This study establishes the feasibility and validity of a new methodology to determine patterns of brand-specific alcohol consumption among underage drinkers. PMID:22014249

  15. THE BOSS EMISSION-LINE LENS SURVEY. IV. SMOOTH LENS MODELS FOR THE BELLS GALLERY SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Yiping [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Bolton, Adam S.; Montero-Dorta, Antonio D.; Cornachione, Matthew A.; Zheng, Zheng; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States); Mao, Shude [Physics Department and Tsinghua Centre for Astrophysics, Tsinghua University, Beijing 100084 (China); Kochanek, Christopher S. [Department of Astronomy and Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Pérez-Fournon, Ismael; Marques-Chaves, Rui [Instituto de Astrofísica de Canarias, C/Vía Láctea, s/n, E-38205 San Cristóbal de La Laguna, Tenerife (Spain); Oguri, Masamune [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ménard, Brice, E-mail: yiping.shu@nao.cas.cn [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2016-12-20

    We present Hubble Space Telescope F606W-band imaging observations of 21 galaxy-Ly α emitter lens candidates in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey (BELLS) for the GALaxy-Ly α EmitteR sYstems (BELLS GALLERY) survey. Seventeen systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately 0.55, while the lensed sources are Ly α emitters (LAEs) at redshifts from two to three. Although most of the lens systems are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thorough exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are, on average, 60% larger than those of the BELLS lenses because of the much higher source redshifts. This will allow for a detailed investigation of the radius evolution of the mass profile in ETGs. With the aid of the average ∼13× lensing magnification, the LAEs are frequently resolved into individual star-forming knots with a wide range of properties. They have characteristic sizes from less than 100 pc to several kiloparsecs, rest-frame far-UV apparent AB magnitudes from 29.6 to 24.2, and typical projected separations of 500 pc to 2 kpc.

  16. The Sloan Digital Sky Survey Quasar Lens Search. IV. Statistical Lens Sample from the Fifth Data Release

    Energy Technology Data Exchange (ETDEWEB)

    Inada, Naohisa; /Wako, RIKEN /Tokyo U., ICEPP; Oguri, Masamune; /Natl. Astron. Observ. of Japan /Stanford U., Phys. Dept.; Shin, Min-Su; /Michigan U. /Princeton U. Observ.; Kayo, Issha; /Tokyo U., ICRR; Strauss, Michael A.; /Princeton U. Observ.; Hennawi, Joseph F.; /UC, Berkeley /Heidelberg, Max Planck Inst. Astron.; Morokuma, Tomoki; /Natl. Astron. Observ. of Japan; Becker, Robert H.; /LLNL, Livermore /UC, Davis; White, Richard L.; /Baltimore, Space Telescope Sci.; Kochanek, Christopher S.; /Ohio State U.; Gregg, Michael D.; /LLNL, Livermore /UC, Davis /Exeter U.

    2010-05-01

    We present the second report of our systematic search for strongly lensed quasars from the data of the Sloan Digital Sky Survey (SDSS). From extensive follow-up observations of 136 candidate objects, we find 36 lenses in the full sample of 77,429 spectroscopically confirmed quasars in the SDSS Data Release 5. We then define a complete sample of 19 lenses, including 11 from our previous search in the SDSS Data Release 3, from the sample of 36,287 quasars with i < 19.1 in the redshift range 0.6 < z < 2.2, where we require the lenses to have image separations of 1 < {theta} < 20 and i-band magnitude differences between the two images smaller than 1.25 mag. Among the 19 lensed quasars, 3 have quadruple-image configurations, while the remaining 16 show double images. This lens sample constrains the cosmological constant to be {Omega}{sub {Lambda}} = 0.84{sub -0.08}{sup +0.06}(stat.){sub -0.07}{sup + 0.09}(syst.) assuming a flat universe, which is in good agreement with other cosmological observations. We also report the discoveries of 7 binary quasars with separations ranging from 1.1 to 16.6, which are identified in the course of our lens survey. This study concludes the construction of our statistical lens sample in the full SDSS-I data set.

  17. The SCPRI (Central Service of Protection against Ionizing Radiation) in France: its sampling and surveying network

    International Nuclear Information System (INIS)

    1994-06-01

    The SCPRI, organism placed under tutelage of Ministers in charge of Health and Work, has the mission to practice every measurement, analysis or dosage of radioactivity or ionizing radiation in media where their presence is a risk for health. This mission involves radioactivity measurement on sampling like waters, air, vegetables, food chain. There is an important network of sampling on the whole national territory with a distribution in different climatic areas and also near the nuclear sites. It makes about 50 000 sampling by year with, for each one, different analysis and measurement

  18. Survey of aflatoxins in retail samples of whole and ground black and white peppercorns.

    Science.gov (United States)

    Adzahan, N; Jalili, M; Jinap, S

    2009-01-01

    A total of 126 local and imported samples of commercial white and black pepper in Malaysia were analysed for aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2) content using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). An acetonitrile-methanol-water (17 : 29 : 54; v/v) mixture was used as a mobile phase and clean-up was using an immunoaffinity column (IAC). Seventy out of 126 (55.5%) samples were contaminated with total aflatoxins, although only low levels of aflatoxins were found ranging from 0.1 to 4.9 ng g(-1). Aflatoxin B1 showed the highest incidence of contamination and was found in all contaminated samples. There was a significant difference between type of samples and different brands (p < 0.05). The results showed black peppers were more contaminated than white peppers.

  19. Micronekton sampling gear Intercalibration Experiment Survey #1 (MIE-1) (SE0413L2, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the cruise was to collect micronekton samples using three different type of midwater trawl: Cobb trawl, Isaacs Kidd Midwater Trawl (IKMT), and a Hokkaido...

  20. Amostra mestra e geoprocessamento: tecnologias para inquéritos domiciliares Master sample and geoprocessing: technologies for household surveys

    Directory of Open Access Journals (Sweden)

    Nilza Nunes da Silva

    2003-08-01

    census enumeration areas in several epidemiological surveys using updated information from the National Survey of Households (PNAD. METHODS: Address data file comprising 72 census enumeration areas was kept as primary sampling units for the city of São Paulo. During the period 1995-2000, three distinct household samples were drawn using the two-stage cluster sampling procedure. Geographic Information System (GIS technology allowed delimiting boundaries, blocks and streets for any primary sampling unit and printing updated maps for selected sub-samples. RESULTS: Twenty-five thousand dwellings made up the permanent address data file of the master sample. A cheaper and quicker selection of each sample, plus gathering information on demographic and topographical profiles of census enumeration areas were the main contribution of the study results. CONCLUSIONS: The master sample concept, integrated with GIS technology, is an advantageous alternative sampling design for household surveys in urban areas. Using the list of addresses from the PNAD updated yearly, although limiting its application to the most populated Brazilian cities, avoids the need of creating an independent sampling procedure for each individual survey carried out in the period between demographic censuses, and it is an important contribution for planning sampling surveys in public health.

  1. Online Education Enters the Mainstream: The 10th Annual Distance Education Survey by the Instructional Technology Council Shows Continued Progress, Maturation

    Science.gov (United States)

    Finkel, Ed

    2015-01-01

    The growth of online education has slowed down among community colleges, but it is still outpacing overall enrollment, while the quality of the education offered has improved from a pale imitation to a worthy competitor, administrators say. More than 5.5 million community college students enrolled in distance education programs in 2013-14,…

  2. A survey of natural terrestrial and airborne radionuclides in moss samples from the peninsular Thailand.

    Science.gov (United States)

    Wattanavatee, Komrit; Krmar, Miodrag; Bhongsuwan, Tripob

    2017-10-01

    The aim of this study was to determine the activity concentrations of natural terrestrial radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) and airborne radionuclides ( 210 Pb, 210 Pb ex and 7 Be) in natural terrestrial mosses. The collected moss samples (46) representing 17 species were collected from 17 sampling localities in the National Parks and Wildlife Sanctuaries of Thailand, situated in the mountainous areas between the northern and the southern ends of peninsular Thailand (∼7-12 °N, 99-102 °E). Activity concentrations of radionuclides in the samples were measured using a low background gamma spectrometer. The results revealed non-uniform spatial distributions of all the radionuclides in the study area. Principal component analysis and cluster analysis revealed two distinct origins for the studied radionuclides, and furthermore, the Pearson correlations were strong within 226 Ra, 232 Th, 238 U and 40 K as well as within 210 Pb and 210 Pb ex , but there was no significant correlation between these two groups. Also 7 Be was uncorrelated to the others, as expected due to different origins of the airborne and terrestrial radionuclides. The radionuclide activities of moss samples varied by moss species, topography, geology, and meteorology of each sampling area. The observed abnormally high concentrations of some radionuclides probably indicate that the concentrations of airborne and terrestrial radionuclides in moss samples were directly related to local geological features of the sampling site, or that high levels of 7 Be were most probably linked with topography and regional NE monsoonal winds from mainland China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. THE SLOAN DIGITAL SKY SURVEY QUASAR LENS SEARCH. IV. STATISTICAL LENS SAMPLE FROM THE FIFTH DATA RELEASE

    International Nuclear Information System (INIS)

    Inada, Naohisa; Oguri, Masamune; Shin, Min-Su; Kayo, Issha; Fukugita, Masataka; Strauss, Michael A.; Gott, J. Richard; Hennawi, Joseph F.; Morokuma, Tomoki; Becker, Robert H.; Gregg, Michael D.; White, Richard L.; Kochanek, Christopher S.; Chiu, Kuenley; Johnston, David E.; Clocchiatti, Alejandro; Richards, Gordon T.; Schneider, Donald P.; Frieman, Joshua A.

    2010-01-01

    We present the second report of our systematic search for strongly lensed quasars from the data of the Sloan Digital Sky Survey (SDSS). From extensive follow-up observations of 136 candidate objects, we find 36 lenses in the full sample of 77,429 spectroscopically confirmed quasars in the SDSS Data Release 5. We then define a complete sample of 19 lenses, including 11 from our previous search in the SDSS Data Release 3, from the sample of 36,287 quasars with i Λ = 0.84 +0.06 -0.08 (stat.) +0.09 -0.07 (syst.) assuming a flat universe, which is in good agreement with other cosmological observations. We also report the discoveries of seven binary quasars with separations ranging from 1.''1 to 16.''6, which are identified in the course of our lens survey. This study concludes the construction of our statistical lens sample in the full SDSS-I data set.

  4. Consistently low prevalence of syphilis among female sex workers in Jinan, China: findings from two consecutive respondent driven sampling surveys.

    Directory of Open Access Journals (Sweden)

    Meizhen Liao

    Full Text Available BACKGROUND: Routine surveillance using convenient sampling found low prevalence of HIV and syphilis among female sex workers in China. Two consecutive surveys using respondent driven sampling were conducted in 2008 and 2009 to examine the prevalence of HIV and syphilis among female sex workers in Jinan, China. METHODS: A face-to-face interview was conducted to collect demographic, behavioral and service utilization information using a structured questionnaire. Blood samples were drawn for serological tests of HIV-1 antibody and syphilis antibody. Respondent Driven Sampling Analysis Tool was used to generate population level estimates. RESULTS: In 2008 and in 2009, 363 and 432 subjects were recruited and surveyed respectively. Prevalence of syphilis was 2.8% in 2008 and 2.2% in 2009, while no HIV case was found in both years. Results are comparable to those from routine sentinel surveillance system in the city. Only 60.8% subjects in 2008 and 48.3% in 2009 reported a consistent condom use with clients during the past month. Over 50% subjects had not been covered by any HIV-related services in the past year, with only 15.6% subjects in 2008 and 13.1% in 2009 ever tested for HIV. CONCLUSIONS: Despite the low prevalence of syphilis and HIV, risk behaviors are common. Targeted interventions to promote the safe sex and utilization of existing intervention services are still needed to keep the epidemic from growing.

  5. Survey of elemental concentrations in lichen samples collected from Sao Paulo State

    International Nuclear Information System (INIS)

    Saiki, M.; Horimoto, L.K.; Vasconcellos, M.B.A.; Coccaro, D.M.B.; Marcelli, M.P.

    2001-01-01

    Samples of the lichen Canoparmelia texana collected in seven different sites of Sao Paulo State and one site of the Parana State were analysed by neutron activation analysis in order to obtain information on the air quality in these regions and also to select a region of interest for the evaluation of baseline level of elements in lichen species. Concentrations of the elements Al, As, Br, Ca, Cd, Cl, Co, Cs, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ti, Th, U, V, Zn and lanthanides were determined and a preliminary comparisons was made between the results obtained for samples collected in different sites. (author)

  6. A study on the representative sampling survey for the inspection of the clearance level for the radioisotope waste

    International Nuclear Information System (INIS)

    Hong Joo Ahn; Se Chul Sohn; Kwang Yong Jee; Ju Youl Kim; In Koo Lee

    2007-01-01

    Utilization facilities for radioisotope (RI) are increasing annually in South Korea, and the total number was 2,723, as of December 31, 2005. The inspection of a clearance level is a very important problem in order to ensure a social reliance for releasing radioactive materials to the environment. Korean regulations for such a clearance are described in Notice No. 2001-30 of the Ministry of Science and Technology (MOST) and Notice No. 2002-67 of the Ministry of Commerce, Industry and Energy (MOCIE). Most unsealed sources in RI waste drums at a storage facility are low-level beta-emitters with short half-lives, so it is impossible to measure their inventories by a nondestructive analysis. Furthermore, RI wastes generated from hospital, educational and research institutes and industry have a heterogeneous, multiple, irregular, and a small quantity of a waste stream. This study addresses a representative (master) sampling survey and analysis plan for RI wastes because a complete enumeration of waste drums is impossible and not desirable in terms of a cost and efficiency. The existing approaches to a representative sampling include a judgmental, simple random, stratified random, systematic grid, systematic random, composite, and adaptive sampling. A representative sampling plan may combine two or more of the above sampling approaches depending on the type and distribution of a waste stream. Stratified random sampling (constrained randomization) is proven to be adequate for a sampling design of a RI waste regarding a half-life, surface dose, undertaking time to a storage facility, and type of waste. The developed sampling protocol includes estimating the number of drums within a waste stream, estimating the number of samples, and a confirmation of the required number of samples. The statistical process control for a quality assurance plan includes control charts and an upper control limit (UCL) of 95% to determine whether a clearance level is met or not. (authors)

  7. Gathering Opinions on Depression Information Needs and Preferences: Samples and Opinions in Clinic Versus Web-Based Surveys.

    Science.gov (United States)

    Bernstein, Matthew T; Walker, John R; Sexton, Kathryn A; Katz, Alan; Beatie, Brooke E

    2017-04-24

    There has been limited research on the information needs and preferences of the public concerning treatment for depression. Very little research is available comparing samples and opinions when recruitment for surveys is done over the Web as opposed to a personal invitation to complete a paper survey. This study aimed to (1) to explore information needs and preferences among members of the public and (2) compare Clinic and Web samples on sample characteristics and survey findings. Web survey participants were recruited with a notice on three self-help association websites (N=280). Clinic survey participants were recruited by a research assistant in the waiting rooms of a family medicine clinic and a walk-in medical clinic (N=238) and completed a paper version of the survey. The Clinic and Web samples were similar in age (39.0 years, SD 13.9 vs 40.2 years, SD 12.5, respectively), education, and proportion in full time employment. The Clinic sample was more diverse in demographic characteristics and closer to the demographic characteristics of the region (Winnipeg, Canada) with a higher proportion of males (102/238 [42.9%] vs 45/280 [16.1%]) and nonwhites (Aboriginal, Asian, and black) (69/238 [29.0%] vs 39/280 [13.9%]). The Web sample reported a higher level of emotional distress and had more previous psychological (224/280 [80.0%] vs 83/238 [34.9%]) and pharmacological (202/280 [72.1%] vs 57/238 [23.9%]) treatment. In terms of opinions, most respondents in both settings saw information on a wide range of topics around depression treatment as very important including information about treatment choices, effectiveness of treatment, how long it takes treatment to work, how long treatment continues, what happens when treatment stops, advantages and disadvantages of treatments, and potential side effects. Females, respondents with a white background, and those who had received or felt they would have benefited from therapy in the past saw more information topics as very

  8. Survey of statistical and sampling needs for environmental monitoring of commercial low-level radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    Eberhardt, L.L.; Thomas, J.M.

    1986-07-01

    This project was designed to develop guidance for implementing 10 CFR Part 61 and to determine the overall needs for sampling and statistical work in characterizing, surveying, monitoring, and closing commercial low-level waste sites. When cost-effectiveness and statistical reliability are of prime importance, then double sampling, compositing, and stratification (with optimal allocation) are identified as key issues. If the principal concern is avoiding questionable statistical practice, then the applicability of kriging (for assessing spatial pattern), methods for routine monitoring, and use of standard textbook formulae in reporting monitoring results should be reevaluated. Other important issues identified include sampling for estimating model parameters and the use of data from left-censored (less than detectable limits) distributions

  9. Interactive Fuzzy Goal Programming approach in multi-response stratified sample surveys

    Directory of Open Access Journals (Sweden)

    Gupta Neha

    2016-01-01

    Full Text Available In this paper, we applied an Interactive Fuzzy Goal Programming (IFGP approach with linear, exponential and hyperbolic membership functions, which focuses on maximizing the minimum membership values to determine the preferred compromise solution for the multi-response stratified surveys problem, formulated as a Multi- Objective Non Linear Programming Problem (MONLPP, and by linearizing the nonlinear objective functions at their individual optimum solution, the problem is approximated to an Integer Linear Programming Problem (ILPP. A numerical example based on real data is given, and comparison with some existing allocations viz. Cochran’s compromise allocation, Chatterjee’s compromise allocation and Khowaja’s compromise allocation is made to demonstrate the utility of the approach.

  10. MANAGERIAL DECISION IN INNOVATIVE EDUCATION SYSTEMS STATISTICAL SURVEY BASED ON SAMPLE THEORY

    Directory of Open Access Journals (Sweden)

    Gheorghe SĂVOIU

    2012-12-01

    Full Text Available Before formulating the statistical hypotheses and the econometrictesting itself, a breakdown of some of the technical issues is required, which are related to managerial decision in innovative educational systems, the educational managerial phenomenon tested through statistical and mathematical methods, respectively the significant difference in perceiving the current qualities, knowledge, experience, behaviour and desirable health, obtained through a questionnaire applied to a stratified population at the end,in the educational environment, either with educational activities, or with simultaneously managerial and educational activities. The details having to do with research focused on the survey theory, turning into a working tool the questionnaires and statistical data that are processed from those questionnaires, are summarized below.

  11. The role of public relations for image creating in health services: a sample patient satisfaction survey.

    Science.gov (United States)

    Kirdar, YalçIn

    2007-01-01

    This study discusses the role of public relations for image creating in health services. Hospitals require public relations activities to distinguish them from competitors, provide bidirectional communication between the society and the hospital, and assist to create of a strong hospital image and culture. A satisfaction survey was conducted on 264 patients who have received health services at Maltepe University Hospital. The research focused on how the Hospital's examination, care, catering and physical services; doctor and nurse politeness towards patients and patient relatives, their attitudes and behaviors; examination, check-in, bedding and discharge operations; public relations activities in and out of the hospital were perceived. Another subject of the study was the degree of recommendation of patients who have been served by the hospital's health services to prospective patients seeking treatment.

  12. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Tonsina area, Valdez Quadrangle, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 128 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Tonsina area in the Chugach Mountains, Valdez quadrangle, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies

  13. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential.The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska.For this report, DGGS funded reanalysis of 105 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Zane Hills area in the Hughes and Shungnak quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical databases of both agencies.

  14. Effort versus Reward: Preparing Samples for Fungal Community Characterization in High-Throughput Sequencing Surveys of Soils.

    Directory of Open Access Journals (Sweden)

    Zewei Song

    Full Text Available Next generation fungal amplicon sequencing is being used with increasing frequency to study fungal diversity in various ecosystems; however, the influence of sample preparation on the characterization of fungal community is poorly understood. We investigated the effects of four procedural modifications to library preparation for high-throughput sequencing (HTS. The following treatments were considered: 1 the amount of soil used in DNA extraction, 2 the inclusion of additional steps (freeze/thaw cycles, sonication, or hot water bath incubation in the extraction procedure, 3 the amount of DNA template used in PCR, and 4 the effect of sample pooling, either physically or computationally. Soils from two different ecosystems in Minnesota, USA, one prairie and one forest site, were used to assess the generality of our results. The first three treatments did not significantly influence observed fungal OTU richness or community structure at either site. Physical pooling captured more OTU richness compared to individual samples, but total OTU richness at each site was highest when individual samples were computationally combined. We conclude that standard extraction kit protocols are well optimized for fungal HTS surveys, but because sample pooling can significantly influence OTU richness estimates, it is important to carefully consider the study aims when planning sampling procedures.

  15. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample

    Science.gov (United States)

    Alam, Shadab; Ata, Metin; Bailey, Stephen; Beutler, Florian; Bizyaev, Dmitry; Blazek, Jonathan A.; Bolton, Adam S.; Brownstein, Joel R.; Burden, Angela; Chuang, Chia-Hsun; Comparat, Johan; Cuesta, Antonio J.; Dawson, Kyle S.; Eisenstein, Daniel J.; Escoffier, Stephanie; Gil-Marín, Héctor; Grieb, Jan Niklas; Hand, Nick; Ho, Shirley; Kinemuchi, Karen; Kirkby, David; Kitaura, Francisco; Malanushenko, Elena; Malanushenko, Viktor; Maraston, Claudia; McBride, Cameron K.; Nichol, Robert C.; Olmstead, Matthew D.; Oravetz, Daniel; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Pellejero-Ibanez, Marcos; Percival, Will J.; Petitjean, Patrick; Prada, Francisco; Price-Whelan, Adrian M.; Reid, Beth A.; Rodríguez-Torres, Sergio A.; Roe, Natalie A.; Ross, Ashley J.; Ross, Nicholas P.; Rossi, Graziano; Rubiño-Martín, Jose Alberto; Saito, Shun; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G.; Satpathy, Siddharth; Schlegel, David J.; Schneider, Donald P.; Scóccola, Claudia G.; Seo, Hee-Jong; Sheldon, Erin S.; Simmons, Audrey; Slosar, Anže; Strauss, Michael A.; Swanson, Molly E. C.; Thomas, Daniel; Tinker, Jeremy L.; Tojeiro, Rita; Magaña, Mariana Vargas; Vazquez, Jose Alberto; Verde, Licia; Wake, David A.; Wang, Yuting; Weinberg, David H.; White, Martin; Wood-Vasey, W. Michael; Yèche, Christophe; Zehavi, Idit; Zhai, Zhongxu; Zhao, Gong-Bo

    2017-09-01

    We present cosmological results from the final galaxy clustering data set of the Baryon Oscillation Spectroscopic Survey, part of the Sloan Digital Sky Survey III. Our combined galaxy sample comprises 1.2 million massive galaxies over an effective area of 9329 deg2 and volume of 18.7 Gpc3, divided into three partially overlapping redshift slices centred at effective redshifts 0.38, 0.51 and 0.61. We measure the angular diameter distance DM and Hubble parameter H from the baryon acoustic oscillation (BAO) method, in combination with a cosmic microwave background prior on the sound horizon scale, after applying reconstruction to reduce non-linear effects on the BAO feature. Using the anisotropic clustering of the pre-reconstruction density field, we measure the product DMH from the Alcock-Paczynski (AP) effect and the growth of structure, quantified by fσ8(z), from redshift-space distortions (RSD). We combine individual measurements presented in seven companion papers into a set of consensus values and likelihoods, obtaining constraints that are tighter and more robust than those from any one method; in particular, the AP measurement from sub-BAO scales sharpens constraints from post-reconstruction BAOs by breaking degeneracy between DM and H. Combined with Planck 2016 cosmic microwave background measurements, our distance scale measurements simultaneously imply curvature ΩK = 0.0003 ± 0.0026 and a dark energy equation-of-state parameter w = -1.01 ± 0.06, in strong affirmation of the spatially flat cold dark matter (CDM) model with a cosmological constant (ΛCDM). Our RSD measurements of fσ8, at 6 per cent precision, are similarly consistent with this model. When combined with supernova Ia data, we find H0 = 67.3 ± 1.0 km s-1 Mpc-1 even for our most general dark energy model, in tension with some direct measurements. Adding extra relativistic species as a degree of freedom loosens the constraint only slightly, to H0 = 67.8 ± 1.2 km s-1 Mpc-1. Assuming flat

  16. Social Distance and Intergenerational Relations

    Science.gov (United States)

    Kidwell, I. Jane; Booth, Alan

    1977-01-01

    Questionnaires were administered to a sample of adults to assess the extent of social distance between people of different ages. The findings suggest that the greater the age difference (younger or older) between people, the greater the social distance they feel. (Author)

  17. THE FMOS-COSMOS SURVEY OF STAR-FORMING GALAXIES AT z ∼ 1.6. III. SURVEY DESIGN, PERFORMANCE, AND SAMPLE CHARACTERISTICS

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, J. D.; Sugiyama, N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, 277-8583 (Japan); Kashino, D. [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya, 464-8602 (Japan); Sanders, D.; Zahid, J.; Kewley, L. J.; Chu, J.; Hasinger, G. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI, 96822 (United States); Kartaltepe, J. S. [National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson, AZ, 85719 (United States); Arimoto, N. [Subaru Telescope, 650 North A’ohoku Place, Hilo, Hawaii, 96720 (United States); Renzini, A. [Instituto Nazionale de Astrofisica, Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, I-35122, Padova, Italy, EU (Italy); Rodighiero, G.; Baronchelli, I. [Dipartimento di Fisica e Astronomia, Universita di Padova, vicolo Osservatorio, 3, I-35122, Padova (Italy); Daddi, E.; Juneau, S. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d’Astrophysique, CEA Saclay (France); Nagao, T. [Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Lilly, S. J.; Carollo, C. M. [Institute of Astronomy, ETH Zürich, CH-8093, Zürich (Switzerland); Capak, P. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Ilbert, O., E-mail: john.silverman@ipmu.jp [Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France); and others

    2015-09-15

    We present a spectroscopic survey of galaxies in the COSMOS field using the Fiber Multi-object Spectrograph (FMOS), a near-infrared instrument on the Subaru Telescope. Our survey is specifically designed to detect the Hα emission line that falls within the H-band (1.6–1.8 μm) spectroscopic window from star-forming galaxies with 1.4 < z < 1.7 and M{sub stellar} ≳ 10{sup 10} M{sub ⊙}. With the high multiplex capability of FMOS, it is now feasible to construct samples of over 1000 galaxies having spectroscopic redshifts at epochs that were previously challenging. The high-resolution mode (R ∼ 2600) effectively separates Hα and [N ii]λ6585, thus enabling studies of the gas-phase metallicity and photoionization state of the interstellar medium. The primary aim of our program is to establish how star formation depends on stellar mass and environment, both recognized as drivers of galaxy evolution at lower redshifts. In addition to the main galaxy sample, our target selection places priority on those detected in the far-infrared by Herschel/PACS to assess the level of obscured star formation and investigate, in detail, outliers from the star formation rate (SFR)—stellar mass relation. Galaxies with Hα detections are followed up with FMOS observations at shorter wavelengths using the J-long (1.11–1.35 μm) grating to detect Hβ and [O iii]λ5008 which provides an assessment of the extinction required to measure SFRs not hampered by dust, and an indication of embedded active galactic nuclei. With 460 redshifts measured from 1153 spectra, we assess the performance of the instrument with respect to achieving our goals, discuss inherent biases in the sample, and detail the emission-line properties. Our higher-level data products, including catalogs and spectra, are available to the community.

  18. Metagenomic survey of bacterial diversity in the atmosphere of Mexico City using different sampling methods.

    Science.gov (United States)

    Serrano-Silva, N; Calderón-Ezquerro, M C

    2018-04-01

    The identification of airborne bacteria has traditionally been performed by retrieval in culture media, but the bacterial diversity in the air is underestimated using this method because many bacteria are not readily cultured. Advances in DNA sequencing technology have produced a broad knowledge of genomics and metagenomics, which can greatly improve our ability to identify and study the diversity of airborne bacteria. However, researchers are facing several challenges, particularly the efficient retrieval of low-density microorganisms from the air and the lack of standardized protocols for sample collection and processing. In this study, we tested three methods for sampling bioaerosols - a Durham-type spore trap (Durham), a seven-day recording volumetric spore trap (HST), and a high-throughput 'Jet' spore and particle sampler (Jet) - and recovered metagenomic DNA for 16S rDNA sequencing. Samples were simultaneously collected with the three devices during one week, and the sequencing libraries were analyzed. A simple and efficient method for collecting bioaerosols and extracting good quality DNA for high-throughput sequencing was standardized. The Durham sampler collected preferentially Cyanobacteria, the HST Actinobacteria, Proteobacteria and Firmicutes, and the Jet mainly Proteobacteria and Firmicutes. The HST sampler collected the largest amount of airborne bacterial diversity. More experiments are necessary to select the right sampler, depending on study objectives, which may require monitoring and collecting specific airborne bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Sampling and monitoring of carbon-14 in gaseous effluents from nuclear facilities - a literature survey

    International Nuclear Information System (INIS)

    Snellman, M.

    1988-12-01

    C-14 compounds produced in the coolant may be released mainly together with off-gas and waste water from the coolant purification and treatment system. In reactors the release of C-14 will occur mainly in gaseous effluents and only a few percent in liquid effluents. Reported releases from BWRs range from 260 to 670 GBq/GW(e) x year and from 90 to 430 GBq/GW(e) x year for PWRs. At BWRs the condenser air ejector contributes the main inplant release pathway, whereas in PWRs the off-gas treatment vents are the main pathway for C-14 release. C-14 sampling methods depend generally on the C-14 being in the form of CO 2 . The off-gas discharges from BWRs are mainly in the form of CO 2 whereas in PWRs a major fraction of the released C-14 is in the form of hydrocarbons or carbon monoxide (generally 80-100%). Sampling systems in PWRs should therefore be equipped with a catalytic oxidizer to convert all C-14 to CO 2 before trapping. The purpose of this study is to provide information on the techniques available for sampling and monitoring C-14

  20. Satellite-aided survey sampling and implementation in low- and middle-income contexts: a low-cost/low-tech alternative.

    Science.gov (United States)

    Haenssgen, Marco J

    2015-01-01

    The increasing availability of online maps, satellite imagery, and digital technology can ease common constraints of survey sampling in low- and middle-income countries. However, existing approaches require specialised software and user skills, professional GPS equipment, and/or commercial data sources; they tend to neglect spatial sampling considerations when using satellite maps; and they continue to face implementation challenges analogous to conventional survey implementation methods. This paper presents an alternative way of utilising satellite maps and digital aides that aims to address these challenges. The case studies of two rural household surveys in Rajasthan (India) and Gansu (China) compare conventional survey sampling and implementation techniques with the use of online map services such as Google, Bing, and HERE maps. Modern yet basic digital technology can be integrated into the processes of preparing, implementing, and monitoring a rural household survey. Satellite-aided systematic random sampling enhanced the spatial representativeness of the village samples and entailed savings of approximately £4000 compared to conventional household listing, while reducing the duration of the main survey by at least 25 %. This low-cost/low-tech satellite-aided survey sampling approach can be useful for student researchers and resource-constrained research projects operating in low- and middle-income contexts with high survey implementation costs. While achieving transparent and efficient survey implementation at low costs, researchers aiming to adopt a similar process should be aware of the locational, technical, and logistical requirements as well as the methodological challenges of this strategy.

  1. Survey of natural and artificial radionuclide contents in soil samples from some areas of the AP Kosovo (Serbia)

    International Nuclear Information System (INIS)

    Adrovic, Feriz; Kosanovic, Katica; Jakupi, Bajram; Krstic, Gordana; Filipovic, Radmila

    2008-01-01

    After the war conflict in the Autonomous Province of Kosovo and Metohija (Serbia), NATO published data on locations where they used ammunition with depleted uranium. In these regions there were localized points of concentrated contamination, so called 'contamination points'. Taking into consideration the amounts of depleted uranium ammunition used by the NATO, obviously the number of these points in the area of Kosovo and Metohija is not negligible. Within the past 7 years there have been conducted various radiological and other surveys in this area. Majority of these surveys were focused around contamination points. The fact is that so far there has been surveyed only a small percentage of the contaminated area in this region, and apparently there are more contamination points outside the surveyed area. Taking into account the mobility of depleted uranium from contaminated areas by various transportation processes (underground waters, winds and diverse mechanical contacts of people, animals, and other activities), the idea of this work was to investigate possible contamination from depleted uranium not only at the locations indicated and published by the NATO in their reports, but also in the wider area around the zones of NATO strikes. In this paper we presented results of gamma spectrometry analysis of soil samples from wider area of the Autonomous Province of Kosovo and Metohija. We used semiconductor HpGe detector with 30% relative efficiency and the resolution FWHM(1332 keV)=1,78 keV. Spectral analysis were made on the basis of the present gamma lines, using a software package. The activity concentrations of the investigated radionuclides in the soil samples were ranged in the following intervals: 226 Ra from 19 to 55 Bq/kg, 235 U from 1,2 to 4,6 Bq/kg, 238 U from 26 to 95 Bq/kg, 40 K from 83 to 648 Bq/kg, 137 Cs from 1 to 176 Bq/kg. (author)

  2. [The methodology and sample description of the National Survey on Addiction Problems in Hungary 2015 (NSAPH 2015)].

    Science.gov (United States)

    Paksi, Borbala; Demetrovics, Zsolt; Magi, Anna; Felvinczi, Katalin

    2017-06-01

    This paper introduces the methods and methodological findings of the National Survey on Addiction Problems in Hungary (NSAPH 2015). Use patterns of smoking, alcohol use and other psychoactive substances were measured as well as that of certain behavioural addictions (problematic gambling - PGSI, DSM-V, eating disorders - SCOFF, problematic internet use - PIUQ, problematic on-line gaming - POGO, problematic social media use - FAS, exercise addictions - EAI-HU, work addiction - BWAS, compulsive buying - CBS). The paper describes the applied measurement techniques, sample selection, recruitment of respondents and the data collection strategy as well. Methodological results of the survey including reliability and validity of the measures are reported. The NSAPH 2015 research was carried out on a nationally representative sample of the Hungarian adult population aged 16-64 yrs (gross sample 2477, net sample 2274 persons) with the age group of 18-34 being overrepresented. Statistical analysis of the weight-distribution suggests that weighting did not create any artificial distortion in the database leaving the representativeness of the sample unaffected. The size of the weighted sample of the 18-64 years old adult population is 1490 persons. The extent of the theoretical margin of error in the weighted sample is ±2,5%, at a reliability level of 95% which is in line with the original data collection plans. Based on the analysis of reliability and the extent of errors beyond sampling within the context of the database we conclude that inconsistencies create relatively minor distortions in cumulative prevalence rates; consequently the database makes possible the reliable estimation of risk factors related to different substance use behaviours. The reliability indexes of measurements used for prevalence estimates of behavioural addictions proved to be appropriate, though the psychometric features in some cases suggest the presence of redundant items. The comparison of

  3. VLA radio-continuum survey of a sample of confirmed and marginal barium stars

    International Nuclear Information System (INIS)

    Drake, S.A.; Simon, T.; Linsky, J.L.

    1987-01-01

    Results are reported from a 6-cm VLA survey of five confirmed Ba II stars and eight mild Ba II stars, undertaken to search for evidence of gyrosynchrotron emission or thermal emission from the primary star's wind that is enhanced or photoionized by a white dwarf companion. Of these 13 stars, only Beta UMi was detected as a possible radio source at a flux level of 0.11 mJy (3sigma). The 6-cm radio luminosities (L6) of the other stars are as small as log L6 less than or equal to 14.0 and are an order of magnitude or more lower than the average levels found in RS CVn systems, but are consistent with the L6 upper limits previously found for stars of spectral type similar to the Ba II stars and normal elemental abundances. The upper limit to the radio luminosity for the possible mild Ba II star 56 Peg, when combined with its previously known X-ray luminosity, may provide useful constraints on the various models that have been proposed for this interesting object, once its orbital period is known. 28 references

  4. Engagement with HIV prevention treatment and care among female sex workers in Zimbabwe: a respondent driven sampling survey.

    Science.gov (United States)

    Cowan, Frances M; Mtetwa, Sibongile; Davey, Calum; Fearon, Elizabeth; Dirawo, Jeffrey; Wong-Gruenwald, Ramona; Ndikudze, Theresa; Chidiya, Samson; Benedikt, Clemens; Busza, Joanna; Hargreaves, James R

    2013-01-01

    To determine the HIV prevalence and extent of engagement with HIV prevention and care among a representative sample of Zimbabwean sex workers working in Victoria Falls, Hwange and Mutare. Respondent driven sampling (RDS) surveys conducted at each site. Sex workers were recruited using respondent driven sampling with each respondent limited to recruiting 2 peers. Participants completed an interviewer-administered questionnaire and provided a finger prick blood sample for HIV antibody testing. Statistical analysis took account of sampling method. 870 women were recruited from the three sites. HIV prevalence was between 50 and 70%. Around half of those confirmed HIV positive were aware of their HIV status and of those 50-70% reported being enrolled in HIV care programmes. Overall only 25-35% of those with laboratory-confirmed HIV were accessing antiretroviral therapy. Among those reporting they were HIV negative, 21-28% reported having an HIV test in the last 6 months. Of those tested HIV negative, most (65-82%) were unaware of their status. Around two-thirds of sex workers reported consistent condom use with their clients. As in other settings, sex workers reported high rates of gender based violence and police harassment. This survey suggests that prevalence of HIV is high among sex workers in Zimbabwe and that their engagement with prevention, treatment and care is sub-optimal. Intensifying prevention and care interventions for sex workers has the potential to markedly reduce HIV and social risks for sex workers, their clients and the general population in Zimbabwe and elsewhere in the region.

  5. Cluster-sample surveys and lot quality assurance sampling to evaluate yellow fever immunisation coverage following a national campaign, Bolivia, 2007.

    Science.gov (United States)

    Pezzoli, Lorenzo; Pineda, Silvia; Halkyer, Percy; Crespo, Gladys; Andrews, Nick; Ronveaux, Olivier

    2009-03-01

    To estimate the yellow fever (YF) vaccine coverage for the endemic and non-endemic areas of Bolivia and to determine whether selected districts had acceptable levels of coverage (>70%). We conducted two surveys of 600 individuals (25 x 12 clusters) to estimate coverage in the endemic and non-endemic areas. We assessed 11 districts using lot quality assurance sampling (LQAS). The lot (district) sample was 35 individuals with six as decision value (alpha error 6% if true coverage 70%; beta error 6% if true coverage 90%). To increase feasibility, we divided the lots into five clusters of seven individuals; to investigate the effect of clustering, we calculated alpha and beta by conducting simulations where each cluster's true coverage was sampled from a normal distribution with a mean of 70% or 90% and standard deviations of 5% or 10%. Estimated coverage was 84.3% (95% CI: 78.9-89.7) in endemic areas, 86.8% (82.5-91.0) in non-endemic and 86.0% (82.8-89.1) nationally. LQAS showed that four lots had unacceptable coverage levels. In six lots, results were inconsistent with the estimated administrative coverage. The simulations suggested that the effect of clustering the lots is unlikely to have significantly increased the risk of making incorrect accept/reject decisions. Estimated YF coverage was high. Discrepancies between administrative coverage and LQAS results may be due to incorrect population data. Even allowing for clustering in LQAS, the statistical errors would remain low. Catch-up campaigns are recommended in districts with unacceptable coverage.

  6. Mean consumption, poverty and inequality in rural India in the 60th round of the National Sample Survey.

    Science.gov (United States)

    Jha, Raghbendra; Gaiha, Raghav; Sharma, Anurag

    2010-01-01

    This article reports on mean consumption, poverty (all three FGT measures) and inequality during 2004 for rural India using National Sample Survey (NSS) data for the 60th Round. Mean consumption at the national level is much higher than the poverty line. However, the Gini coefficient is higher than in recent earlier rounds. The headcount ratio is 22.9 per cent. Mean consumption, all three measures of poverty and the Gini coefficient are computed at the level of 20 states and 63 agro-climatic zones in these 20 states. It is surmised that despite impressive growth rates deprivation is pervasive, pockets of severe poverty persist, and inequality is rampant.

  7. Effects of distances and company resources for enterprise export performance

    Directory of Open Access Journals (Sweden)

    Givanildo Silva

    2015-12-01

    Full Text Available The purpose of this article is to evaluate the effect of distance on the export performance of companies in Santa Catarina, and to what extent this effect is moderated by organizational resource characteristics. Multiple linear regression and variance analysis were used for a perception survey of export managers with a final sample of 49 exporting producers. The constructs showed internal validity and allowed the data to be analyzed. The results only revealed evidence regarding the effect of psychic distance, showing a positive relationship with export performance. Also, the model estimation showed that the organization's resources moderate the relation between distance and export performance. Finally the study also shows that the export team and the organizational structure moderate the effect of distance on the performance and future performance expectations of the companies.

  8. [Personality Traits Screening in a Colombian Adult Population Sample - Colombian National Survey of Mental Health-2015].

    Science.gov (United States)

    Oviedo, Gabriel Fernando; Gómez-Restrepo, Carlos; Rondón, Martín; Borda Bohigas, Juan Pablo; Tamayo Martínez, Nathalie

    2016-12-01

    Personality refers to the individual style in characteristic patterns of thinking, feeling and behaving. Traits may configure a personality disorder when there is a long-lasting rigid pattern of inner experience that deviates from the expectations of the individual's culture, are inflexible and form maladaptative schemes in different interpersonal scenarios. Given the pervasiveness of this structure, they cause impairment of functioning in the affected person. To establish the prevalence of personality traits in all selected adults, using the module-structured interview WHO WHM-CIDI-CAPI for clusters A, B and C of personality traits. Colombian National Survey on Mental Health with persons older than 18 years of age. Personality traits that are the most frequently described: Cluster A 46% (95%CI, 45.2-48.1) of people believe they are convinced that there are conspiracies behind many things in the world. Regarding the features of cluster B, 35.6% (95%CI, 34.2-37.0) of the population reports that generally they do not feel bad when offending or upsetting someone and 35.4% (95%CI, 33.9-36.8) refer to show feelings to anyone. The highest proportion of traits were found to the probable borderline personality disorder, as 4.6% (95%CI, 4.1-5.2) of the Colombian population aged 18 and older has 6 or more features of this type, and is the widely reported as an individual entity with similar rates in men and women. The high prevalence of disruptive personality traits requires more research. The high prevalence reported for borderline personality traits suggests the need to implement measures to improve and integrate a collaborative model of care for people afflicted with a possible borderline personality disorder. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  9. Fuel demand elasticities for energy and environmental policies: Indian sample survey evidence

    International Nuclear Information System (INIS)

    Gundimeda, Haripriya; Koehlin, Gunnar

    2008-01-01

    India has been running large-scale interventions in the energy sector over the last decades. Still, there is a dearth of reliable and readily available price and income elasticities of demand to base these on, especially for domestic use of traditional fuels. This study uses the linear approximate Almost Ideal Demand System (LA-AIDS) using micro data of more than 100,000 households sampled across India. The LA-AIDS model is expanded by specifying the intercept as a linear function of household characteristics. Marshallian and Hicksian price and expenditure elasticities of demand for four main fuels are estimated for both urban and rural areas by different income groups. These can be used to evaluate recent and current energy policies. The results can also be used for energy projections and carbon dioxide simulations given different growth rates for different segments of the Indian population. (author)

  10. Decision Tree and Survey Development for Support in Agricultural Sampling Strategies during Nuclear and Radiological Emergencies

    International Nuclear Information System (INIS)

    Yi, Amelia Lee Zhi; Dercon, Gerd

    2017-01-01

    In the event of a severe nuclear or radiological accident, the release of radionuclides results in contamination of land surfaces affecting agricultural and food resources. Speedy accumulation of information and guidance on decision making is essential in enhancing the ability of stakeholders to strategize for immediate countermeasure strategies. Support tools such as decision trees and sampling protocols allow for swift response by governmental bodies and assist in proper management of the situation. While such tools exist, they focus mainly on protecting public well-being and not food safety management strategies. Consideration of the latter is necessary as it has long-term implications especially to agriculturally dependent Member States. However, it is a research gap that remains to be filled.

  11. X-ray microanalytical surveys of minor element concentrations in unsectioned biological samples

    Science.gov (United States)

    Schofield, R. M. S.; Lefevre, H. W.; Overley, J. C.; Macdonald, J. D.

    1988-03-01

    Approximate concentration maps of small unsectioned biological samples are made using the pixel by pixel ratio of PIXE images to areal density images. Areal density images are derived from scanning transmission ion microscopy (STIM) proton energy-loss images. Corrections for X-ray production cross section variations, X-ray attenuation, and depth averaging are approximated or ignored. Estimates of the magnitude of the resulting error are made. Approximate calcium concentrations within the head of a fruit fly are reported. Concentrations in the retinula cell region of the eye average about 1 mg/g dry weight. Concentrations of zinc in the mandible of several ant species average about 40 mg/g. Zinc concentrations in the stomachs of these ants are at least 1 mg/g.

  12. How serious a problem is subsoil compaction in the Netherlands? A survey based on probability sampling

    Science.gov (United States)

    Brus, Dick J.; van den Akker, Jan J. H.

    2018-02-01

    Although soil compaction is widely recognized as a soil threat to soil resources, reliable estimates of the acreage of overcompacted soil and of the level of soil compaction parameters are not available. In the Netherlands data on subsoil compaction were collected at 128 locations selected by stratified random sampling. A map showing the risk of subsoil compaction in five classes was used for stratification. Measurements of bulk density, porosity, clay content and organic matter content were used to compute the relative bulk density and relative porosity, both expressed as a fraction of a threshold value. A subsoil was classified as overcompacted if either the relative bulk density exceeded 1 or the relative porosity was below 1. The sample data were used to estimate the means of the two subsoil compaction parameters and the overcompacted areal fraction. The estimated global means of relative bulk density and relative porosity were 0.946 and 1.090, respectively. The estimated areal fraction of the Netherlands with overcompacted subsoils was 43 %. The estimates per risk map unit showed two groups of map units: a low-risk group (units 1 and 2, covering only 4.6 % of the total area) and a high-risk group (units 3, 4 and 5). The estimated areal fraction of overcompacted subsoil was 0 % in the low-risk unit and 47 % in the high-risk unit. The map contains no information about where overcompacted subsoils occur. This was caused by the poor association of the risk map units 3, 4 and 5 with the subsoil compaction parameters and subsoil overcompaction. This can be explained by the lack of time for recuperation.

  13. Using Social Media and Targeted Snowball Sampling to Survey a Hard-to-reach Population: A Case Study

    Directory of Open Access Journals (Sweden)

    Gary Dusek

    2015-08-01

    Full Text Available Response rates to the academic surveys used in quantitative research are decreasing and have been for several decades among both individuals and organizations. Given this trend, providing doctoral students an opportunity to complete their dissertations in a timely and cost effective manner may necessitate identifying more innovative and relevant ways to collect data while maintaining appropriate research standards and rigor. The case of a research study is presented which describes the data collection process used to survey a hard-to-reach population. It details the use of social media, in this case LinkedIn, to facilitate the distribution of the web-based survey. A roadmap to illustrate how this data collection process unfolded is presented, as well as several “lessons learned” during this journey. An explanation of the considerations that impacted the sampling design is provided. The goal of this case study is to provide researchers, including doctoral students, with realistic expectations and an awareness of the benefits and risks associated with the use of this method of data collection.

  14. [A respondent-driven sampling survey on HIV and risk factors among men who have sex with men in Chongqing].

    Science.gov (United States)

    Ouyang, Lin; Feng, Lian-gui; Ding, Xian-bin; Zhao, Jin-kou; Xu, Jing; Han, Mei; Zhou, Chao

    2009-10-01

    To examine HIV prevalence and related risk factors among men who have sex with men (MSM) in Chongqing, and to explore the feasibility of using respondent-driven sampling (RDS) in the survey. Based on results from formative research, a RDS survey was designed and conducted to collect demographic, behavioral and serologic data. RDSAT was used to calculate point estimation and confidence intervals. SPSS was used for bi-variate analysis using RDSAT exported weighed data. NETDRAW was used to draw network diagram. Among 617 subjects recruited, the adjusted HIV and syphilis prevalence rates were 16.8% and 10.9%, respectively. 73.0% of the subjects were 20 to 29 years old and 72.9% were officially registered residents of Chongqing. 83.4% were single, with the proportion of students the highest, accounting for 24.6%. During the last six months, 83.4% of them reported ever having anal sex, and 54.0% reported having unprotected anal sex. This survey confirmed that Chongqing had a higher reported HIV prevalence among MSM than from other Chinese cities. Comprehensive intervention services were required to address this alarmingly high prevalence, with focus on intervention through internet and those having syphilis infection. RDS seemed one of the effective ways of recruiting hidden MSM populations in Chongqing which had a large population of active MSM who did not frequently visit MSM venues as compared with snowball method.

  15. New cosmological constraints with extended-Baryon Oscillation Spectroscopic Survey DR14 quasar sample

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lu; Wang, Ke [Institute of Theoretical Physics, Chinese Academy of Sciences, CAS Key Laboratory of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China); Huang, Qing-Guo [Institute of Theoretical Physics, Chinese Academy of Sciences, CAS Key Laboratory of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China); Hunan Normal University, Synergetic Innovation Center for Quantum Effects and Applications, Changsha (China)

    2017-11-15

    We update the constraints on the cosmological parameters by adopting the Planck data released in 2015 and baryon acoustic oscillation (BAO) measurements including the new DR14 quasar sample measurement at redshift z = 1.52, and we conclude that the six-parameter ΛCDM model is preferred. Exploring some extensions to the ΛCDM model, we find that the equation of state of dark energy reads w = -1.036 ± 0.056 in the wCDM model, the effective number of relativistic degrees of freedom in the Universe is N{sub eff} = 3.09{sub -0.20}{sup +0.18} in the N{sub eff} + ΛCDM model and the spatial curvature parameter is Ω{sub k} = (1.8 ± 1.9) x 10{sup -3} in the Ω{sub k} + ΛCDM model at 68% confidence level (C.L.), and the 95% C.L. upper bounds on the sum of three active neutrinos masses are sum m{sub ν} < 0.16 eV for the normal hierarchy (NH) and sum m{sub ν} < 0.19 eV for the inverted hierarchy (IH) with Δχ{sup 2} ≡ χ{sup 2}{sub NH} - χ{sup 2}{sub IH} = -1.25. (orig.)

  16. Preliminary survey of potato virus Y (PVy) strains in potato samples from Kurdistan (Iran).

    Science.gov (United States)

    Bahrami-Kamangar, S; De Jonghe, K; Kamangar, S; Maes, M; Smagghe, G

    2010-01-01

    Potato virus Y (PVY) is the type species in the potyvirus genus of the family potyviridae. This plant pathogenic virus is transmitted through plant sap inoculation by stem and core grafting and by at least 25 aphid species in a non-persistent manner. According to potato specialists in most parts of the world, PVY is currently considered as the most harmful virus in cultivated potatoes. This is also the case for potato production in Iran. In this project we investigated potato leaves that were collected in the Kurdistan province in Iran for the presence of PVY with use of different biochemical/molecular techniques as ELISA, RT-PCR and qPCR. The different PVY strains, including PVY-O, PVY-N, PVYN-TN, PVY-NWi, were determined by using a triplex RT-PCR. In conclusion, the results demonstrated the presence of PVY-NWi strains in the potato leaf samples from Kurdistan (Iran). The data are discussed in relation to prevalence of PVY strains in Iran.

  17. Sampling and analysis plan for the preoperational environmental survey of the spent nuclear fuel project facilities

    International Nuclear Information System (INIS)

    MITCHELL, R.M.

    1999-01-01

    This sampling and analysis plan will support the preoperational environmental monitoring for construction, development, and operation of the Spent Nuclear Fuel (SNF) Project facilities, which have been designed for the conditioning and storage of spent nuclear fuels; particularly the fuel elements associated with the operation of N-Reactor. The SNF consists principally of irradiated metallic uranium, and therefore includes plutonium and mixed fission products. The primary effort will consist of removing the SNF from the storage basins in K East and K West Areas, placing in multicanister overpacks, vacuum drying, conditioning, and subsequent dry vault storage in the 200 East Area. The primary purpose and need for this action is to reduce the risks to public health and safety and to the environment. Specifically these include prevention of the release of radioactive materials into the air or to the soil surrounding the K Basins, prevention of the potential migration of radionuclides through the soil column to the nearby Columbia River, reduction of occupational radiation exposure, and elimination of the risks to the public and to workers from the deterioration of SNF in the K Basins

  18. Random sampling of quantum states: a survey of methods and some issues regarding the Overparametrized Method

    International Nuclear Information System (INIS)

    Maziero, Jonas

    2015-01-01

    The numerical generation of random quantum states (RQS) is an important procedure for investigations in quantum information science. Here, we review some methods that may be used for performing that task. We start by presenting a simple procedure for generating random state vectors, for which the main tool is the random sampling of unbiased discrete probability distributions (DPD). Afterwards, the creation of random density matrices is addressed. In this context, we first present the standard method, which consists in using the spectral decomposition of a quantum state for getting RQS from random DPDs and random unitary matrices. In the sequence, the Bloch vector parametrization method is described. This approach, despite being useful in several instances, is not in general convenient for RQS generation. In the last part of the article, we regard the overparametrized method (OPM) and the related Ginibre and Bures techniques. The OPM can be used to create random positive semidefinite matrices with unit trace from randomly produced general complex matrices in a simple way that is friendly for numerical implementations. We consider a physically relevant issue related to the possible domains that may be used for the real and imaginary parts of the elements of such general complex matrices. Subsequently, a too fast concentration of measure in the quantum state space that appears in this parametrization is noticed. (author)

  19. Evaluation of carbon monoxide in blood samples from the second health and nutrition survey. Progress report No. 1

    Energy Technology Data Exchange (ETDEWEB)

    Radford, E.P.

    1976-01-01

    This is a study of carbon monoxide (CO) in the blood of human subjects participating in the Second National Health and Nutrition Survey (HANES II), a detailed study of health indicators in sample populations of many communities throughout the U.S. The purpose of this aspect of the survey is to evaluate the levels of blood carboxyhemoglobin in normal individuals of all ages in typical U.S. communities, from whom accurate histories and clinical studies are available. This report gives results of the first of three years of analyses. A careful calibration of the analytical method has been completed, and more than 3000 blood samples have been analyzed. Although smoking histories are not yet available to permit evaluation of carboxyhemoglobin in non-smokers, in children under 12 years of age, blood COHb has been found to be consistently low, with less than 3% greater than 1.5% COHb. These preliminary results suggest that urban exposure to carbon monoxide among the general population is not now significant in the U.S., at least during the period of these early examinations.

  20. Sample substitution can be an acceptable data-collection strategy: the case of the Belgian Health Interview Survey.

    Science.gov (United States)

    Demarest, Stefaan; Molenberghs, Geert; Van der Heyden, Johan; Gisle, Lydia; Van Oyen, Herman; de Waleffe, Sandrine; Van Hal, Guido

    2017-11-01

    Substitution of non-participating households is used in the Belgian Health Interview Survey (BHIS) as a method to obtain the predefined net sample size. Yet, possible effects of applying substitution on response rates and health estimates remain uncertain. In this article, the process of substitution with its impact on response rates and health estimates is assessed. The response rates (RR)-both at household and individual level-according to the sampling criteria were calculated for each stage of the substitution process, together with the individual accrual rate (AR). Unweighted and weighted health estimates were calculated before and after applying substitution. Of the 10,468 members of 4878 initial households, 5904 members (RRind: 56.4%) of 2707 households (RRhh: 55.5%) participated. For the three successive (matched) substitutes, the RR dropped to 45%. The composition of the net sample resembles the one of the initial samples. Applying substitution did not produce any important distorting effects on the estimates. Applying substitution leads to an increase in non-participation, but does not impact the estimations.

  1. Multiple surveys employing a new sample-processing protocol reveal the genetic diversity of placozoans in Japan.

    Science.gov (United States)

    Miyazawa, Hideyuki; Nakano, Hiroaki

    2018-03-01

    Placozoans, flat free-living marine invertebrates, possess an extremely simple bauplan lacking neurons and muscle cells and represent one of the earliest-branching metazoan phyla. They are widely distributed from temperate to tropical oceans. Based on mitochondrial 16S rRNA sequences, 19 haplotypes forming seven distinct clades have been reported in placozoans to date. In Japan, placozoans have been found at nine locations, but 16S genotyping has been performed at only two of these locations. Here, we propose a new processing protocol, "ethanol-treated substrate sampling," for collecting placozoans from natural environments. We also report the collection of placozoans from three new locations, the islands of Shikine-jima, Chichi-jima, and Haha-jima, and we present the distribution of the 16S haplotypes of placozoans in Japan. Multiple surveys conducted at multiple locations yielded five haplotypes that were not reported previously, revealing high genetic diversity in Japan, especially at Shimoda and Shikine-jima Island. The observed geographic distribution patterns were different among haplotypes; some were widely distributed, while others were sampled only from a single location. However, samplings conducted on different dates at the same sites yielded different haplotypes, suggesting that placozoans of a given haplotype do not inhabit the same site constantly throughout the year. Continued sampling efforts conducted during all seasons at multiple locations worldwide and the development of molecular markers within the haplotypes are needed to reveal the geographic distribution pattern and dispersal history of placozoans in greater detail.

  2. Enantioselective analysis of chloramphenicol residues in honey samples by chiral LC-MS/MS and results of a honey survey.

    Science.gov (United States)

    Rimkus, Gerhard G; Hoffmann, Dirk

    2017-06-01

    Chloramphenicol (CAP) is a broad-spectrum antibiotic used widely in both human and veterinary medication. Since 1994, CAP has not been authorised for use in food-producing animals in the European Union due to several adverse effects. A minimum required performance level (MRPL) of 0.3 µg kg - 1 was established in 2003. The CAP molecule contains two asymmetric centres, thus in total four para-CAP stereoisomers exist. Only the RR-CAP enantiomer is bioactive, having significant antimicrobial activity. For the first time a chiral LC-MS/MS method is reported to identify and quantify the four CAP enantiomers at residue levels in honey samples. The method was validated at two concentration levels. The decision limits (CCα) and detection capabilities (CCß) were well below 0.3 µg kg - 1 , with limits of quantification (LOQs) between 0.08 and 0.12 µg kg - 1 for all four enantiomers. The method provides a sensitive and reliable analysis of CAP enantiomers in honey, and proved its robustness during the daily routine analyses of numerous honey samples. In an internal honey survey, in total 40 honey samples from different geographical regions with identified CAP residues at or above the MRPL were reanalysed by chiral LC-MS/MS. In nine honey samples only the bioactive RR-CAP was detected as anticipated. However, in all other 31 honey samples the non-bioactive SS-CAP was also identified and quantified unambiguously. In 10 of these samples, mixtures of RR- and SS-CAP were analysed, and in 21 samples only the SS-CAP enantiomer, with concentrations up to 2.2 µg kg - 1 . Most of these samples are honeys from Ukraine and Eastern Europe. This is the first report of SS-CAP residues in food samples. The potential sources for these findings are discussed and the need of further systematic studies emphasised. It is recommended to examine in more depth the toxicological profile of the individual CAP stereoisomers.

  3. Determination of the Flux-distance Relationship for Pulsars in the Parkes Multibeam Survey: Violation of the Inverse Square Law Gives Support for a New Model of Pulsar Emission

    Science.gov (United States)

    Singleton, John; Sengupta, P.; Middleditch, J.; Graves, T.; Schmidt, A.; Perez, M.; Ardavan, H.; Ardavan, A.; Fasel, J.

    2010-01-01

    Soon after the discovery of pulsars, it was realized that their unique periodic emissions must be associated with a source that rotates. Despite this insight and forty one years of subsequent effort, a detailed understanding of the pulsar emission mechanism has proved elusive. Here, using data for 983 pulsars taken from the Parkes Multibeam Survey, we show that their fluxes at 1400 MHz (S(1400)) decay with distance d according to a non-standard power-law; we suggest that S(1400) is proportional to 1/d. This distance dependence is revealed by two independent statistical techniques, (i) the Maximum Likelihood Method and (ii) analysis of the distance evolution of the cumulative distribution functions of pulsar flux. Moreover, the derived power law is valid for both millisecond and longer-period pulsars, and is robust against possible errors in the NE2001 method for obtaining pulsar distances from dispersion measure. This observation provides strong support for a mechanism of pulsar emission due to superluminal (faster than light in vacuo) polarization currents. Such superluminal polarization currents have been extensively studied by Bolotovskii, Ginzburg and others, who showed both that they do not violate Special Relativity (since the oppositely-charged particles that make them move relatively slowly) and that they form a bona-fide source term in Maxwell's equations. Subsequently, emission of radiation by superluminal polarization currents was demonstrated in laboratory experiments. By extending these ideas to a superluminal polarization current whose distribution pattern follows a circular orbit, we can explain the 1/d dependence of the flux suggested by our analyses of the observational data. In addition, we show that a model of pulsar emission due to such a rotating superluminal polarization current can predict the the frequency spectrum of nine pulsars over 16 orders of magnitude of frequency quantitatively. This work is supported by the DoE LDRD program at Los

  4. Planning with Reachable Distances

    KAUST Repository

    Tang, Xinyu

    2009-01-01

    Motion planning for spatially constrained robots is difficult due to additional constraints placed on the robot, such as closure constraints for closed chains or requirements on end effector placement for articulated linkages. It is usually computationally too expensive to apply sampling-based planners to these problems since it is difficult to generate valid configurations. We overcome this challenge by redefining the robot\\'s degrees of freedom and constraints into a new set of parameters, called reachable distance space (RD-space), in which all configurations lie in the set of constraint-satisfying subspaces. This enables us to directly sample the constrained subspaces with complexity linear in the robot\\'s number of degrees of freedom. In addition to supporting efficient sampling, we show that the RD-space formulation naturally supports planning, and in particular, we design a local planner suitable for use by sampling-based planners. We demonstrate the effectiveness and efficiency of our approach for several systems including closed chain planning with multiple loops, restricted end effector sampling, and on-line planning for drawing/sculpting. We can sample single-loop closed chain systems with 1000 links in time comparable to open chain sampling, and we can generate samples for 1000-link multi-loop systems of varying topology in less than a second. © 2009 Springer-Verlag.

  5. Learner characteristics involved in distance learning

    Energy Technology Data Exchange (ETDEWEB)

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  6. 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.

  7. A within-sample investigation of test–retest reliability in choice experiment surveys with real economic incentives

    DEFF Research Database (Denmark)

    Mørkbak, Morten Raun; Olsen, Søren Bøye

    2015-01-01

    In this paper, we investigate the level of agreement between respondents' choices in identical choice sets in a test-retest choice experiment for a market good with real economic incentives, thus investigating whether the incentivised CE method can be reliable and stable over time. Besides...... comparing choices, we also test for differences in preferences and error variance when a sample of respondents is given the exact same questionnaire twice, with a time lag of 2 weeks in between. Finally, we examine potential reasons and covariates explaining the level of agreement in choices across the 2...... weeks. Across four different tests, we find very good agreement between the two choice experiments - both with respect to overall choices and with respect to preferences. Furthermore, error variances do not differ significantly between the two surveys. The results also show that the larger the utility...

  8. [Trends and factors associated with food insecurity in Brazil: the National Household Sample Survey, 2004, 2009, and 2013].

    Science.gov (United States)

    Santos, Taíse Gama Dos; Silveira, Jonas Augusto Cardoso da; Longo-Silva, Giovana; Ramires, Elyssia Karine Nunes Mendonça; Menezes, Risia Cristina Egito de

    2018-03-29

    The aim of this study was to analyze trends and factors associated with food insecurity in Brazil in 2004, 2009, and 2013, using microdata from the National Household Sample Survey (PNAD). Food insecurity was assessed using the Brazilian Food Insecurity Scale. Independent variables were selected from a conceptual model of determination of food insecurity, which was also used in the elaboration of multiple generalized linear models. The results show a downward trend in food insecurity prevalence from 2004 to 2013, especially for moderate and severe food insecurity, from 17% in 2004 (95%CI: 15.7-18.4) to 7.9% in 2013 (95%CI: 7.2-8.7). Despite important decreases in the prevalence of moderate and severe food insecurity, regardless of the level of determination, the population strata with the lowest prevalence in 2004 showed the largest relative reduction. As for factors associated with moderate and severe food insecurity, they remained the same in the ten years covered by the PNAD survey, namely: the North and Northeast regions, urban areas with inadequate sanitation, household density > 2 persons per bedroom, ≤ 4 household durable consumer goods, and households headed by females, individuals insecurity dropped by half, but from the perspective of equity the advances occurred unequally and were lower in strata with greater social, economic, and demographic vulnerability.

  9. Surface radiation survey and soil sampling of the 300-FF-1 operable unit, Hanford Site, southeastern Washington: A case study

    International Nuclear Information System (INIS)

    Teel, S.S.; Olsen, K.B.

    1990-10-01

    The methods used for conducting a radiological characterization of the soil surface for the Phase I Remedial Investigation of a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) site is presented via a case study. The study site is an operable unit (300-FF-1) located in and adjacent to the 300 Area of the US Department of Energy's Hanford Site in southeastern Washington State. The operable unit contains liquid and solid waste disposal facilities associated with nuclear fuels fabrication. Continuous surface radiation surveying and soil sampling of selected locations were conducted. Contamination was found in several locations within the operable unit including areas near the liquid and solid waste disposal facilities. Instruments used during surveying included portable beta/gamma (P-11) detectors, and the Ultrasonic Ranging and Data System using an NaI (Tl) detector. Laboratory analyses results indicate that above-background radiation levels were primarily due to the presence of uranium. Both types of field instruments used in the study were effective in detecting surface contamination from radionuclides; however, each had specific advantages. Guidelines are presented for the optimum use of these instruments when performing a radiological characterization of the soil surface. 4 refs., 3 figs., 3 tabs

  10. The NuSTAR  Extragalactic Surveys: X-Ray Spectroscopic Analysis of the Bright Hard-band Selected Sample

    Science.gov (United States)

    Zappacosta, L.; Comastri, A.; Civano, F.; Puccetti, S.; Fiore, F.; Aird, J.; Del Moro, A.; Lansbury, G. B.; Lanzuisi, G.; Goulding, A.; Mullaney, J. R.; Stern, D.; Ajello, M.; Alexander, D. M.; Ballantyne, D. R.; Bauer, F. E.; Brandt, W. N.; Chen, C.-T. J.; Farrah, D.; Harrison, F. A.; Gandhi, P.; Lanz, L.; Masini, A.; Marchesi, S.; Ricci, C.; Treister, E.

    2018-02-01

    We discuss the spectral analysis of a sample of 63 active galactic nuclei (AGN) detected above a limiting flux of S(8{--}24 {keV})=7× {10}-14 {erg} {{{s}}}-1 {{cm}}-2 in the multi-tiered NuSTAR extragalactic survey program. The sources span a redshift range z=0{--}2.1 (median =0.58). The spectral analysis is performed over the broad 0.5–24 keV energy range, combining NuSTAR with Chandra and/or XMM-Newton data and employing empirical and physically motivated models. This constitutes the largest sample of AGN selected at > 10 {keV} to be homogeneously spectrally analyzed at these flux levels. We study the distribution of spectral parameters such as photon index, column density ({N}{{H}}), reflection parameter ({\\boldsymbol{R}}), and 10–40 keV luminosity ({L}{{X}}). Heavily obscured ({log}[{N}{{H}}/{{cm}}-2]≥slant 23) and Compton-thick (CT; {log}[{N}{{H}}/{{cm}}-2]≥slant 24) AGN constitute ∼25% (15–17 sources) and ∼2–3% (1–2 sources) of the sample, respectively. The observed {N}{{H}} distribution agrees fairly well with predictions of cosmic X-ray background population-synthesis models (CXBPSM). We estimate the intrinsic fraction of AGN as a function of {N}{{H}}, accounting for the bias against obscured AGN in a flux-selected sample. The fraction of CT AGN relative to {log}[{N}{{H}}/{{cm}}-2]=20{--}24 AGN is poorly constrained, formally in the range 2–56% (90% upper limit of 66%). We derived a fraction (f abs) of obscured AGN ({log}[{N}{{H}}/{{cm}}-2]=22{--}24) as a function of {L}{{X}} in agreement with CXBPSM and previous zvalues.

  11. Estimating diurnal primate densities using distance sampling ...

    African Journals Online (AJOL)

    SARAH

    2016-03-31

    Mar 31, 2016 ... In the second session, we used 10 transect adjusted to transect (Grid 17 ... session transect was visited 20 times while at the second session transect ... probability, the density of the group and the group size of each species ...

  12. Distance determinations to shield galaxies from Hubble space telescope imaging

    Energy Technology Data Exchange (ETDEWEB)

    McQuinn, Kristen B. W.; Skillman, Evan D. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street, S.E., Minneapolis, MN 55455 (United States); Cannon, John M.; Cave, Ian [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 E. Hermans Road, Tucson, AZ 85756 (United States); Salzer, John J. [Department of Astronomy, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Haynes, Martha P.; Adams, Elizabeth; Giovanelli, Riccardo [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Elson, Ed C. [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Ott, Juërgen [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801 (United States); Saintonge, Amélie, E-mail: kmcquinn@astro.umn.edu [Max-Planck-Institute for Astrophysics, D-85741 Garching (Germany)

    2014-04-10

    The Survey of H I in Extremely Low-mass Dwarf (SHIELD) galaxies is an ongoing multi-wavelength program to characterize the gas, star formation, and evolution in gas-rich, very low-mass galaxies. The galaxies were selected from the first ∼10% of the H I Arecibo Legacy Fast ALFA (ALFALFA) survey based on their inferred low H I mass and low baryonic mass, and all systems have recent star formation. Thus, the SHIELD sample probes the faint end of the galaxy luminosity function for star-forming galaxies. Here, we measure the distances to the 12 SHIELD galaxies to be between 5 and 12 Mpc by applying the tip of the red giant method to the resolved stellar populations imaged by the Hubble Space Telescope. Based on these distances, the H I masses in the sample range from 4 × 10{sup 6} to 6 × 10{sup 7} M {sub ☉}, with a median H I mass of 1 × 10{sup 7} M {sub ☉}. The tip of the red giant branch distances are up to 73% farther than flow-model estimates in the ALFALFA catalog. Because of the relatively large uncertainties of flow-model distances, we are biased toward selecting galaxies from the ALFALFA catalog where the flow model underestimates the true distances. The measured distances allow for an assessment of the native environments around the sample members. Five of the galaxies are part of the NGC 672 and NGC 784 groups, which together constitute a single structure. One galaxy is part of a larger linear ensemble of nine systems that stretches 1.6 Mpc from end to end. Three galaxies reside in regions with 1-9 neighbors, and four galaxies are truly isolated with no known system identified within a radius of 1 Mpc.

  13. Sex and gender diversity among transgender persons in Ontario, Canada: results from a respondent-driven sampling survey.

    Science.gov (United States)

    Scheim, Ayden I; Bauer, Greta R

    2015-01-01

    Recent estimates suggest that as many as 1 in 200 adults may be trans (transgender, transsexual, or transitioned). Knowledge about dimensions of sex and gender in trans populations is crucial to development of inclusive policy, practice, and research, but limited data have been available, particularly from probability samples. The Trans PULSE community-based research project surveyed trans Ontarians (n=433) in 2009-2010 using respondent-driven sampling. Frequencies were weighted by recruitment probability to produce estimates for the networked Ontario trans population. An estimated 30% of trans Ontarians were living their day-to-day lives in their birth gender, and 23% were living in their felt gender with no medical intervention. In all, 42% were using hormones, while 15% of male-to-female spectrum persons had undergone vaginoplasty and 0.4% of female-to-male spectrum persons had had phalloplasty. Of those living in their felt gender, 59% had begun to do so within the past four years. A minority of trans Ontarians reported a linear transition from one sex to another, yet such a trajectory is often assumed to be the norm. Accounting for this observed diversity, we recommend policy and practice changes to increase social inclusion and service access for trans persons, regardless of transition status.

  14. Sex and Gender Diversity Among Transgender Persons in Ontario, Canada: Results From a Respondent-Driven Sampling Survey

    Science.gov (United States)

    Scheim, Ayden I.; Bauer, Greta R.

    2015-01-01

    Recent estimates suggest that as many as 1 in 200 adults may be trans (transgender, transsexual, or transitioned). Knowledge about dimensions of sex and gender in trans populations is crucial to development of inclusive policy, practice, and research, but limited data have been available, particularly from probability samples. The Trans PULSE community-based research project surveyed trans Ontarians (n = 433) in 2009–2010 using respondent-driven sampling. Frequencies were weighted by recruitment probability to produce estimates for the networked Ontario trans population. An estimated 30% of trans Ontarians were living their day-to-day lives in their birth gender, and 23% were living in their felt gender with no medical intervention. In all, 42% were using hormones, while 15% of male-to-female spectrum persons had undergone vaginoplasty and 0.4% of female-to-male spectrum persons had had phalloplasty. Of those living in their felt gender, 59% had begun to do so within the past four years. A minority of trans Ontarians reported a linear transition from one sex to another, yet such a trajectory is often assumed to be the norm. Accounting for this observed diversity, we recommend policy and practice changes to increase social inclusion and service access for trans persons, regardless of transition status. PMID:24750105

  15. Development and enrolee satisfaction with basic medical insurance in China: A systematic review and stratified cluster sampling survey.

    Science.gov (United States)

    Jing, Limei; Chen, Ru; Jing, Lisa; Qiao, Yun; Lou, Jiquan; Xu, Jing; Wang, Junwei; Chen, Wen; Sun, Xiaoming

    2017-07-01

    Basic Medical Insurance (BMI) has changed remarkably over time in China because of health reforms that aim to achieve universal coverage and better health care with adequate efforts by increasing subsidies, reimbursement, and benefits. In this paper, we present the development of BMI, including financing and operation, with a systematic review. Meanwhile, Pudong New Area in Shanghai was chosen as a typical BMI sample for its coverage and management; a stratified cluster sampling survey together with an ordinary logistic regression model was used for the analysis. Enrolee satisfaction and the factors associated with enrolee satisfaction with BMI were analysed. We found that the reenrolling rate superficially improved the BMI coverage and nearly achieved universal coverage. However, BMI funds still faced dual contradictions of fund deficit and insured under compensation, and a long-term strategy is needed to realize the integration of BMI schemes with more homogeneous coverage and benefits. Moreover, Urban Resident Basic Medical Insurance participants reported a higher rate of dissatisfaction than other participants. The key predictors of the enrolees' satisfaction were awareness of the premium and compensation, affordability of out-of-pocket costs, and the proportion of reimbursement. These results highlight the importance that the Chinese government takes measures, such as strengthening BMI fund management, exploring mixed payment methods, and regulating sequential medical orders, to develop an integrated medical insurance system of universal coverage and vertical equity while simultaneously improving enrolee satisfaction. Copyright © 2017 John Wiley & Sons, Ltd.

  16. The Swift/BAT AGN Spectroscopic Survey. IX. The Clustering Environments of an Unbiased Sample of Local AGNs

    Science.gov (United States)

    Powell, M. C.; Cappelluti, N.; Urry, C. M.; Koss, M.; Finoguenov, A.; Ricci, C.; Trakhtenbrot, B.; Allevato, V.; Ajello, M.; Oh, K.; Schawinski, K.; Secrest, N.

    2018-05-01

    We characterize the environments of local accreting supermassive black holes by measuring the clustering of AGNs in the Swift/BAT Spectroscopic Survey (BASS). With 548 AGN in the redshift range 0.01 2MASS galaxies, and interpreting it via halo occupation distribution and subhalo-based models, we constrain the occupation statistics of the full sample, as well as in bins of absorbing column density and black hole mass. We find that AGNs tend to reside in galaxy group environments, in agreement with previous studies of AGNs throughout a large range of luminosity and redshift, and that on average they occupy their dark matter halos similar to inactive galaxies of comparable stellar mass. We also find evidence that obscured AGNs tend to reside in denser environments than unobscured AGNs, even when samples were matched in luminosity, redshift, stellar mass, and Eddington ratio. We show that this can be explained either by significantly different halo occupation distributions or statistically different host halo assembly histories. Lastly, we see that massive black holes are slightly more likely to reside in central galaxies than black holes of smaller mass.

  17. Predicting and retrodicting intelligence between childhood and old age in the 6-Day Sample of the Scottish Mental Survey 1947.

    Science.gov (United States)

    Deary, Ian J; Brett, Caroline E

    2015-01-01

    In studies of cognitive ageing it is useful and important to know how stable are the individual differences in cognitive ability from childhood to older age, and also to be able to estimate (retrodict) prior cognitive ability differences from those in older age. Here we contribute to these aims with new data from a follow-up study of the 6-Day Sample of the Scottish Mental Survey of 1947 (original N = 1208). The sample had cognitive, educational, social, and occupational data collected almost annually from age 11 to 27 years. Whereas previous long-term follow-up studies of the Scottish mental surveys are based upon group-administered cognitive tests at a mean age of 11 years, the present sample each had an individually-administered revised Binet test. We traced them for vital status in older age, and some agreed to take several mental tests at age 77 years (N = 131). The National Adult Reading Test at age 77 correlated .72 with the Terman-Merrill revision of the Binet Test at age 11. Adding the Moray House Test No. 12 score from age 11 and educational information took the multiple R to .81 between youth and older age. The equivalent multiple R for fluid general intelligence was .57. When the NART from age 77 was the independent variable (retrodictor) along with educational attainment, the multiple R with the Terman-Merrill IQ at age 11 was .75. No previous studies of the stability of intelligence from childhood to old age, or of the power of the NART to retrodict prior intelligence, have had individually-administered IQ data from youth. About two-thirds, at least, of the variation in verbal ability in old age can be captured by cognitive and educational information from youth. Non-verbal ability is less well predicted. A short test of pronunciation-the NART-and brief educational information can capture well over half of the variation in IQ scores obtained 66 years earlier.

  18. Analytic processing of distance.

    Science.gov (United States)

    Dopkins, Stephen; Galyer, Darin

    2018-01-01

    How does a human observer extract from the distance between two frontal points the component corresponding to an axis of a rectangular reference frame? To find out we had participants classify pairs of small circles, varying on the horizontal and vertical axes of a computer screen, in terms of the horizontal distance between them. A response signal controlled response time. The error rate depended on the irrelevant vertical as well as the relevant horizontal distance between the test circles with the relevant distance effect being larger than the irrelevant distance effect. The results implied that the horizontal distance between the test circles was imperfectly extracted from the overall distance between them. The results supported an account, derived from the Exemplar Based Random Walk model (Nosofsky & Palmieri, 1997), under which distance classification is based on the overall distance between the test circles, with relevant distance being extracted from overall distance to the extent that the relevant and irrelevant axes are differentially weighted so as to reduce the contribution of irrelevant distance to overall distance. The results did not support an account, derived from the General Recognition Theory (Ashby & Maddox, 1994), under which distance classification is based on the relevant distance between the test circles, with the irrelevant distance effect arising because a test circle's perceived location on the relevant axis depends on its location on the irrelevant axis, and with relevant distance being extracted from overall distance to the extent that this dependency is absent. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A large sample of Kohonen selected E+A (post-starburst) galaxies from the Sloan Digital Sky Survey

    Science.gov (United States)

    Meusinger, H.; Brünecke, J.; Schalldach, P.; in der Au, A.

    2017-01-01

    Context. The galaxy population in the contemporary Universe is characterised by a clear bimodality, blue galaxies with significant ongoing star formation and red galaxies with only a little. The migration between the blue and the red cloud of galaxies is an issue of active research. Post starburst (PSB) galaxies are thought to be observed in the short-lived transition phase. Aims: We aim to create a large sample of local PSB galaxies from the Sloan Digital Sky Survey (SDSS) to study their characteristic properties, particularly morphological features indicative of gravitational distortions and indications for active galactic nuclei (AGNs). Another aim is to present a tool set for an efficient search in a large database of SDSS spectra based on Kohonen self-organising maps (SOMs). Methods: We computed a huge Kohonen SOM for ∼106 spectra from SDSS data release 7. The SOM is made fully available, in combination with an interactive user interface, for the astronomical community. We selected a large sample of PSB galaxies taking advantage of the clustering behaviour of the SOM. The morphologies of both PSB galaxies and randomly selected galaxies from a comparison sample in SDSS Stripe 82 (S82) were inspected on deep co-added SDSS images to search for indications of gravitational distortions. We used the Portsmouth galaxy property computations to study the evolutionary stage of the PSB galaxies and archival multi-wavelength data to search for hidden AGNs. Results: We compiled a catalogue of 2665 PSB galaxies with redshifts z 3 Å and z cloud, in agreement with the idea that PSB galaxies represent the transitioning phase between actively and passively evolving galaxies. The relative frequency of distorted PSB galaxies is at least 57% for EW(Hδ) > 5 Å, significantly higher than in the comparison sample. The search for AGNs based on conventional selection criteria in the radio and MIR results in a low AGN fraction of ∼2-3%. We confirm an MIR excess in the mean SED of

  20. 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.

  1. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2016-01-01

    This 4th edition of the leading reference volume on distance metrics is characterized by updated and rewritten sections on some items suggested by experts and readers, as well a general streamlining of content and the addition of essential new topics. Though the structure remains unchanged, the new edition also explores recent advances in the use of distances and metrics for e.g. generalized distances, probability theory, graph theory, coding theory, data analysis. New topics in the purely mathematical sections include e.g. the Vitanyi multiset-metric, algebraic point-conic distance, triangular ratio metric, Rossi-Hamming metric, Taneja distance, spectral semimetric between graphs, channel metrization, and Maryland bridge distance. The multidisciplinary sections have also been supplemented with new topics, including: dynamic time wrapping distance, memory distance, allometry, atmospheric depth, elliptic orbit distance, VLBI distance measurements, the astronomical system of units, and walkability distance. Lea...

  2. Measuring and testing dependence by correlation of distances

    OpenAIRE

    Székely, Gábor J.; Rizzo, Maria L.; Bakirov, Nail K.

    2007-01-01

    Distance correlation is a new measure of dependence between random vectors. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but unlike the classical definition of correlation, distance correlation is zero only if the random vectors are independent. The empirical distance dependence measures are based on certain Euclidean distances between sample elements rather than sample moments, yet have a compact representation analogous to the clas...

  3. Survey of maternal sleep practices in late pregnancy in a multi-ethnic sample in South Auckland, New Zealand.

    Science.gov (United States)

    Cronin, Robin S; Chelimo, Carol; Mitchell, Edwin A; Okesene-Gafa, Kara; Thompson, John M D; Taylor, Rennae S; Hutchison, B Lynne; McCowan, Lesley M E

    2017-06-17

    The Auckland Stillbirth study demonstrated a two-fold increased risk of late stillbirth for women who did not go to sleep on their left side. Two further studies have confirmed an increased risk of late stillbirth with supine sleep position. As sleep position is modifiable, we surveyed self-reported late pregnancy sleep position, knowledge about sleep position, and views about changing going-to-sleep position. Participants in this 2014 survey were pregnant women (n = 377) in their third trimester from South Auckland, New Zealand, a multi-ethnic and predominantly low socio-economic population. An ethnically-representative sample was obtained using random sampling. Multivariable logistic regression was performed to identify factors independently associated with non-left sided going-to-sleep position in late pregnancy. Respondents were 28 to 42 weeks' gestation. Reported going-to-sleep position in the last week was left side (30%), right side (22%), supine (3%), either side (39%) and other (6%). Two thirds (68%) reported they had received advice about sleep position. Non-left sleepers were asked if they would be able to change to their left side if it was better for their baby; 87% reported they would have little or no difficulty changing. Women who reported a non-left going-to-sleep position were more likely to be of Maori (aOR 2.64 95% CI 1.23-5.66) or Pacific (aOR 2.91 95% CI 1.46-5.78) ethnicity; had a lower body mass index (BMI) (aOR 0.93 95% CI 0.89-0.96); and were less likely to sleep on the left-hand side of the bed (aOR 3.29 95% CI 2.03-5.32). Maternal going-to-sleep position in the last week was side-lying in 91% of participants. The majority had received advice to sleep on their side or avoid supine sleep position. Sleeping on the left-hand side of the bed was associated with going-to-sleep on the left side. Most non-left sleepers reported their sleeping position could be modified to the left side suggesting a public health intervention about sleep

  4. 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.

  5. Factors influencing social distance toward people with mental illness.

    Science.gov (United States)

    Lauber, Christoph; Nordt, Carlos; Falcato, Luis; Rössler, Wulf

    2004-06-01

    When identifying ways to reduce stigmatization because of mental illness it is crucial to understand contributing factors. Social distance-the willingness to engage in relationships of varying intimacy with a person--is an indicator of public attitudes toward persons with mental illness. Multiple linear regression analysis of the results of a vignette-based opinion survey conducted on a representative population sample in Switzerland (n = 594). The level of social distance increases if situations imply 'social closeness.' The vignette describing a person with schizophrenia, attitudes to general aspects of mental health (lay helping, community psychiatry), emotions toward those affected, and the attitude toward consequences of mental illness (medical treatment, medication side effects, negative sanctions, e.g. withdrawal of the driver license) were found to predict social distance. Demographic factors such as age, gender, and the cultural background influence social distance. The explained variance (R2) is 44.8%. Social distance is a multifaceted concept influenced by, e.g., socio-economic and cultural factors, but also by the respondent's general attitude toward (mental) health issues. These results suggest that more knowledge about mental illnesses, especially schizophrenia, may increase social distance. The findings presented here may help to focus anti-stigma campaigns not only on transmission of knowledge, but on integrating different approaches.

  6. The Sloan Lens ACS Survey. I. A large spectroscopically selected sample of massive early-type lens galaxies

    NARCIS (Netherlands)

    Bolton, AS; Burles, S; Koopmans, LVE; Treu, T; Moustakas, LA

    2006-01-01

    The Sloan Lens ACS (SLACS) Survey is an efficient Hubble Space Telescope (HST) Snapshot imaging survey for new galaxy-scale strong gravitational lenses. The targeted lens candidates are selected spectroscopically from the Sloan Digital Sky Survey (SDSS) database of galaxy spectra for having multiple

  7. The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: measurement of the growth rate of structure from the anisotropic correlation function between redshift 0.8 and 2.2

    Science.gov (United States)

    Zarrouk, Pauline; Burtin, Etienne; Gil-Marín, Héctor; Ross, Ashley J.; Tojeiro, Rita; Pâris, Isabelle; Dawson, Kyle S.; Myers, Adam D.; Percival, Will J.; Chuang, Chia-Hsun; Zhao, Gong-Bo; Bautista, Julian; Comparat, Johan; González-Pérez, Violeta; Habib, Salman; Heitmann, Katrin; Hou, Jiamin; Laurent, Pierre; Le Goff, Jean-Marc; Prada, Francisco; Rodríguez-Torres, Sergio A.; Rossi, Graziano; Ruggeri, Rossana; Sánchez, Ariel G.; Schneider, Donald P.; Tinker, Jeremy L.; Wang, Yuting; Yèche, Christophe; Baumgarten, Falk; Brownstein, Joel R.; de la Torre, Sylvain; du Mas des Bourboux, Hélion; Kneib, Jean-Paul; Mariappan, Vivek; Palanque-Delabrouille, Nathalie; Peacock, John; Petitjean, Patrick; Seo, Hee-Jong; Zhao, Cheng

    2018-06-01

    We present the clustering measurements of quasars in configuration space based on the Data Release 14 (DR14) of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (eBOSS). This data set includes 148 659 quasars spread over the redshift range 0.8 ≤ z ≤ 2.2 and spanning 2112.9 deg2. We use the Convolution Lagrangian Perturbation Theory approach with a Gaussian Streaming model for the redshift space distortions of the correlation function and demonstrate its applicability for dark matter haloes hosting eBOSS quasar tracers. At the effective redshift zeff = 1.52, we measure the linear growth rate of structure fσ8(zeff) = 0.426 ± 0.077, the expansion rate H(z_eff)= 159^{+12}_{-13}(rs^fid/r_s) {{}km s}^{-1} Mpc^{-1}, and the angular diameter distance DA(z_eff)=1850^{+90}_{-115} (r_s/rs^fid) {}Mpc, where rs is the sound horizon at the end of the baryon drag epoch and rs^fid is its value in the fiducial cosmology. The quoted uncertainties include both systematic and statistical contributions. The results on the evolution of distances are consistent with the predictions of flat Λ-cold dark matter cosmology with Planck parameters, and the measurement of fσ8 extends the validity of General Relativity to higher redshifts (z > 1). This paper is released with companion papers using the same sample. The results on the cosmological parameters of the studies are found to be in very good agreement, providing clear evidence of the complementarity and of the robustness of the first full-shape clustering measurements with the eBOSS DR14 quasar sample.

  8. The Effects of Organizational Justice on Positive Organizational Behavior: Evidence from a Large-Sample Survey and a Situational Experiment

    Science.gov (United States)

    Pan, Xiaofu; Chen, Mengyan; Hao, Zhichao; Bi, Wenfen

    2018-01-01

    Employees' positive organizational behavior (POB) is not only to promote organizational function but also improve individual and organizational performance. As an important concept in organizational research, organizational justice is thought to be a universal predictor of employee and organizational outcomes. The current set of two studies examined the effects of organizational justice (OJ) on POB of employees with two different studies, a large-sample survey and a situational experiment. In study 1, a total of 2,566 employees from 45 manufacturing enterprises completed paper-and-pencil questionnaires assessing organizational justice (OJ) and positive organizational behavior (POB) of employees. In study 2, 747 employees were randomly sampled to participate in the situational experiment with 2 × 2 between-subjects design. They were asked to read one of the four situational stories and to image that this situation happen to the person in the story or them, and then they were asked to imagine how the person in the story or they would have felt and what the person or they subsequently would have done. The results of study 1 suggested that OJ was correlated with POB of employees and OJ is a positive predictor of POB. The results of study 2 suggested that OJ had significant effects on POB and negative organizational behavior (NOB). Procedural justice accounted for significantly more variance than distributive justice in POB of employees. Distributive justice and procedural justice have different influences on POB and NOB in terms of effectiveness and direction. The effect of OJ on POB was greater than that of NOB. In addition, path analysis indicated that the direct effect of OJ on POB was smaller than its indirect effect. Thus, many intermediary effects could possibly be between them. PMID:29375434

  9. The Effects of Organizational Justice on Positive Organizational Behavior: Evidence from a Large-Sample Survey and a Situational Experiment.

    Science.gov (United States)

    Pan, Xiaofu; Chen, Mengyan; Hao, Zhichao; Bi, Wenfen

    2017-01-01

    Employees' positive organizational behavior (POB) is not only to promote organizational function but also improve individual and organizational performance. As an important concept in organizational research, organizational justice is thought to be a universal predictor of employee and organizational outcomes. The current set of two studies examined the effects of organizational justice (OJ) on POB of employees with two different studies, a large-sample survey and a situational experiment. In study 1, a total of 2,566 employees from 45 manufacturing enterprises completed paper-and-pencil questionnaires assessing organizational justice (OJ) and positive organizational behavior (POB) of employees. In study 2, 747 employees were randomly sampled to participate in the situational experiment with 2 × 2 between-subjects design. They were asked to read one of the four situational stories and to image that this situation happen to the person in the story or them, and then they were asked to imagine how the person in the story or they would have felt and what the person or they subsequently would have done. The results of study 1 suggested that OJ was correlated with POB of employees and OJ is a positive predictor of POB. The results of study 2 suggested that OJ had significant effects on POB and negative organizational behavior (NOB). Procedural justice accounted for significantly more variance than distributive justice in POB of employees. Distributive justice and procedural justice have different influences on POB and NOB in terms of effectiveness and direction. The effect of OJ on POB was greater than that of NOB. In addition, path analysis indicated that the direct effect of OJ on POB was smaller than its indirect effect. Thus, many intermediary effects could possibly be between them.

  10. An international survey of decabromodiphenyl ethane (deBDethane) and decabromodiphenyl ether (decaBDE) in sewage sludge samples.

    Science.gov (United States)

    Ricklund, Niklas; Kierkegaard, Amelie; McLachlan, Michael S

    2008-12-01

    Decabromodiphenyl ethane (deBDethane) is an additive flame retardant marketed as a replacement for decabromodiphenyl ether (decaBDE). The structures of the two chemicals are similar, and hence deBDethane may also become an environmental contaminant of concern. Environmental data on deBDethane are scarce. Since sewage sludge is an early indicator of leakage of these chemicals into the environment, an international survey of deBDethane and decaBDE levels in sludge was conducted. Samples were collected from 42 WWTPs in 12 different countries and analyzed with GC/LRMS. DeBDethane was present in sludge from all countries and may therefore be a worldwide concern. The levels of deBDethane in sludge samples from the Ruhr area of Germany were the highest so far reported in the literature (216 ng g(-1)d.wt.). The [deBDethane]/[decaBDE] quotient for the whole data set ranged from 0.0018 to 0.83. High ratios were found in and around Germany where deBDethane imports are known to have been high and substitution of decaBDE with deBDethane is likely to have occurred. Low ratios were found in the USA and the UK, countries that have traditionally been large users of decaBDE. An estimate of the flux of deBDEthane from the technosphere via WWTPs to the environment within the European Union gave 1.7+/-0.34 mg annually per person. The corresponding value for decaBDE was 41+/-22 mg annually per person.

  11. Re-evaluation and extension of the scope of elements in US Geological Survey Standard Reference Water Samples

    Science.gov (United States)

    Peart, D.B.; Antweiler, Ronald C.; Taylor, Howard E.; Roth, D.A.; Brinton, T.I.

    1998-01-01

    More than 100 US Geological Survey (USGS) Standard Reference Water Samples (SRWSs) were analyzed for numerous trace constituents, including Al, As, B, Ba, Be, Bi, Br, Cd, Cr, Co, Cu, I, Fe, Pb, Li, Mn, Mo, Ni, Rb, Sb, Se, Sr, Te, Tl, U, V, Zn and major elements (Ca, Mg, Na, SiO2, SO4, Cl) by inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. In addition, 15 USGS SRWSs and National Institute of Standards and Technology (NIST) standard reference material (SRM) 1641b were analyzed for mercury using cold vapor atomic fluorescence spectrometry. Also USGS SRWS Hg-7 was analyzed using isotope dilution-inductively coupled plasma mass spectrometry. The results were compared with the reported certified values of the following standard reference materials: NIST SRM 1643a, 1643b, 1643c and 1643d and National Research Council of Canada Riverine Water Reference Materials for Trace Metals SLRS-1, SLRS-2 and SLRS-3. New concentration values for trace and major elements in the SRWSs, traceable to the certified standards, are reported. Additional concentration values are reported for elements that were neither previously published for the SRWSs nor traceable to the certified reference materials. Robust statistical procedures were used that were insensitive to outliers. These data can be used for quality assurance/quality control purposes in analytical laboratories.

  12. A cross-sectional, randomized cluster sample survey of household vulnerability to extreme heat among slum dwellers in ahmedabad, india.

    Science.gov (United States)

    Tran, Kathy V; Azhar, Gulrez S; Nair, Rajesh; Knowlton, Kim; Jaiswal, Anjali; Sheffield, Perry; Mavalankar, Dileep; Hess, Jeremy

    2013-06-18

    Extreme heat is a significant public health concern in India; extreme heat hazards are projected to increase in frequency and severity with climate change. Few of the factors driving population heat vulnerability are documented, though poverty is a presumed risk factor. To facilitate public health preparedness, an assessment of factors affecting vulnerability among slum dwellers was conducted in summer 2011 in Ahmedabad, Gujarat, India. Indicators of heat exposure, susceptibility to heat illness, and adaptive capacity, all of which feed into heat vulnerability, was assessed through a cross-sectional household survey using randomized multistage cluster sampling. Associations between heat-related morbidity and vulnerability factors were identified using multivariate logistic regression with generalized estimating equations to account for clustering effects. Age, preexisting medical conditions, work location, and access to health information and resources were associated with self-reported heat illness. Several of these variables were unique to this study. As sociodemographics, occupational heat exposure, and access to resources were shown to increase vulnerability, future interventions (e.g., health education) might target specific populations among Ahmedabad urban slum dwellers to reduce vulnerability to extreme heat. Surveillance and evaluations of future interventions may also be worthwhile.

  13. 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.

  14. Student and Faculty Issues in Distance Education.

    Science.gov (United States)

    Fender, David L.

    Occupational safety and health faculty and occupational safety and health professionals (i.e., the potential audience for graduate level distance education programs) were surveyed to determine the considerations for a distance education-based graduate occupational safety and health program. Findings are reported related to the demand for distance…

  15. Training for Distance Teaching through Distance Learning.

    Science.gov (United States)

    Cadorath, Jill; Harris, Simon; Encinas, Fatima

    2002-01-01

    Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

  16. The Distance Standard Deviation

    OpenAIRE

    Edelmann, Dominic; Richards, Donald; Vogel, Daniel

    2017-01-01

    The distance standard deviation, which arises in distance correlation analysis of multivariate data, is studied as a measure of spread. New representations for the distance standard deviation are obtained in terms of Gini's mean difference and in terms of the moments of spacings of order statistics. Inequalities for the distance variance are derived, proving that the distance standard deviation is bounded above by the classical standard deviation and by Gini's mean difference. Further, it is ...

  17. Comparação de tamanhos e distâncias de subparcelas aplicadas em processo de amostragem por conglomerado Comparison of sizes and distances of subplots applied in the process of cluster sampling

    Directory of Open Access Journals (Sweden)

    Oberdan Müller M. das Flores

    2012-09-01

    Full Text Available Realizou-se um estudo com unidades amostrais conglomeradas de estrutura cruzada usando banco de dados de inventário florestal 100% de uma Unidade de produção Anual (UPA-08, localizada na fazenda Martins no alto Pacajá, Município de Portel, Estado do Pará, para estudar os efeitos da variação entre e dentro dos conglomerados usando como referência três variáveis resposta: i VT = Volume total de madeira das 77 espécies florestais encontradas na área de estudo; ii VO = Volume Total das 10 espécies florestais de maior ocorrência e volume na área de estudo; e iii VC = Volume Total das 10 espécies florestais mais comercializadas pela empresa Cikel, tendo como objetivo determinar o tamanho e a distância ideal de subparcelas a partir do Método da Curvatura Máxima, uma vez definido o tamanho, sua área é fixada e então são estudadas cinco diferentes valores para determinar a distancia ideal do centro do conglomerado até as subparcelas e entre as mesmas. Os resultados permitiram inferir que o tamanho de subparcela 0,10 ha, a distância de 50 m entre as subparcelas, e a estrutura cruzada com 8 (subparcelas são eficientes para estimar os parâmetros estudados.We conducted a study with sample units of conglomerate structure using cross-database of forest inventory 100% of Annual Production Unit (APU-08, located at the Top Pacajá Martins farm, municipality of Portel-PA to study the effects of variation between and within clusters with reference to three response variables they were: i VT = Total volume of wood of 77 tree species found in the study area, ii VO = Total Volume of the 10 most frequent tree species and volume in the study area and, iii Vt = Total volume of 10 forest species Cikel more commercialized by the company we aimed to determine the ideal size and distance of plots from the Method of Maximum Curvature, once defined the size, its area was fixed and then there was tested five different values to determine the ideal

  18. Turkish University Students' Technology Use Profiles and Their Thoughts about Distance Education

    Science.gov (United States)

    Baran, Bahar; Kilic, Eylem; Bakar Corez, Aysegul; Cagiltay, Kursat

    2010-01-01

    This study presents the results of a survey implemented to investigate Turkish university students' technology use profile and their thoughts about distance education. The sample of the study is 6504 students from four universities in Turkey. The results of the study are reported in five main sections: 1) demographic information of the students,…

  19. Alcohol Use Disorders in National Samples of Mexicans and Mexican-Americans: The Mexican National Addiction Survey and the U.S. National Alcohol Survey

    Science.gov (United States)

    Borges, Guilherme; Medina-Mora, Maria Elena; Lown, Anne; Ye, Yu; Robertson, Marjorie J.; Cherpitel, Cheryl; Greenfield, Tom

    2006-01-01

    The authors show associations between immigration and alcohol disorders using data from the 1995 and 2000 U.S. National Alcohol Surveys and the 1998 Mexico National Household Survey on Addictions. The prevalence of alcohol dependence was 4.8% for the Mexicans, 4.2% for the Mexico-born immigrants, and 6.6% for the U.S.-born Mexican Americans. They…

  20. Mobile acoustic transects miss rare bat species: implications of survey method and spatio-temporal sampling for monitoring bats

    Directory of Open Access Journals (Sweden)

    Elizabeth C. Braun de Torrez

    2017-11-01

    Full Text Available Due to increasing threats facing bats, long-term monitoring protocols are needed to inform conservation strategies. Effective monitoring should be easily repeatable while capturing spatio-temporal variation. Mobile acoustic driving transect surveys (‘mobile transects’ have been touted as a robust, cost-effective method to monitor bats; however, it is not clear how well mobile transects represent dynamic bat communities, especially when used as the sole survey approach. To assist biologists who must select a single survey method due to resource limitations, we assessed the effectiveness of three acoustic survey methods at detecting species richness in a vast protected area (Everglades National Park: (1 mobile transects, (2 stationary surveys that were strategically located by sources of open water and (3 stationary surveys that were replicated spatially across the landscape. We found that mobile transects underrepresented bat species richness compared to stationary surveys across all major vegetation communities and in two distinct seasons (dry/cool and wet/warm. Most critically, mobile transects failed to detect three rare bat species, one of which is federally endangered. Spatially replicated stationary surveys did not estimate higher species richness than strategically located stationary surveys, but increased the rate at which species were detected in one vegetation community. The survey strategy that detected maximum species richness and the highest mean nightly species richness with minimal effort was a strategically located stationary detector in each of two major vegetation communities during the wet/warm season.

  1. Mobile acoustic transects miss rare bat species: implications of survey method and spatio-temporal sampling for monitoring bats.

    Science.gov (United States)

    Braun de Torrez, Elizabeth C; Wallrichs, Megan A; Ober, Holly K; McCleery, Robert A

    2017-01-01

    Due to increasing threats facing bats, long-term monitoring protocols are needed to inform conservation strategies. Effective monitoring should be easily repeatable while capturing spatio-temporal variation. Mobile acoustic driving transect surveys ('mobile transects') have been touted as a robust, cost-effective method to monitor bats; however, it is not clear how well mobile transects represent dynamic bat communities, especially when used as the sole survey approach. To assist biologists who must select a single survey method due to resource limitations, we assessed the effectiveness of three acoustic survey methods at detecting species richness in a vast protected area (Everglades National Park): (1) mobile transects, (2) stationary surveys that were strategically located by sources of open water and (3) stationary surveys that were replicated spatially across the landscape. We found that mobile transects underrepresented bat species richness compared to stationary surveys across all major vegetation communities and in two distinct seasons (dry/cool and wet/warm). Most critically, mobile transects failed to detect three rare bat species, one of which is federally endangered. Spatially replicated stationary surveys did not estimate higher species richness than strategically located stationary surveys, but increased the rate at which species were detected in one vegetation community. The survey strategy that detected maximum species richness and the highest mean nightly species richness with minimal effort was a strategically located stationary detector in each of two major vegetation communities during the wet/warm season.

  2. British Association for the Study of Community Dentistry (BASCD) guidance on sampling for surveys of child dental health. A BASCD coordinated dental epidemiology programme quality standard.

    Science.gov (United States)

    Pine, C M; Pitts, N B; Nugent, Z J

    1997-03-01

    The British Association for the Study of Community Dentistry (BASCD) is responsible for the coordination of locally based surveys of child dental health which permit local and national comparisons between health authorities and regions. These surveys began in 1985/86 in England and Wales, 1987/88 in Scotland and 1993/94 in Northern Ireland. BASCD has taken an increasing lead in setting quality standards in discussion with the NHS Epidemiology Coordinators of the Dental Epidemiology Programme. This paper comprises guidance on the sampling for these surveys.

  3. Use of Distance Education in Dental Hygiene Programs.

    Science.gov (United States)

    Grimes, Ellen B.

    2002-01-01

    Surveyed dental hygiene programs to determine the prevalence of distance education use. Found that 22 percent have distance education, and that most were satisfied with it as an adequate alternative to traditional approaches. (EV)

  4. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2014-01-01

    This updated and revised third edition of the leading reference volume on distance metrics includes new items from very active research areas in the use of distances and metrics such as geometry, graph theory, probability theory and analysis. Among the new topics included are, for example, polyhedral metric space, nearness matrix problems, distances between belief assignments, distance-related animal settings, diamond-cutting distances, natural units of length, Heidegger’s de-severance distance, and brain distances. The publication of this volume coincides with intensifying research efforts into metric spaces and especially distance design for applications. Accurate metrics have become a crucial goal in computational biology, image analysis, speech recognition and information retrieval. Leaving aside the practical questions that arise during the selection of a ‘good’ distance function, this work focuses on providing the research community with an invaluable comprehensive listing of the main available di...

  5. A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

    Directory of Open Access Journals (Sweden)

    Galway LP

    2012-04-01

    Full Text Available Abstract Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

  6. Preferences for Internet-Based Mental Health Interventions in an Adult Online Sample: Findings From an Online Community Survey.

    Science.gov (United States)

    Batterham, Philip J; Calear, Alison L

    2017-06-30

    Despite extensive evidence that Internet interventions are effective in treating mental health problems, uptake of Internet programs is suboptimal. It may be possible to make Internet interventions more accessible and acceptable through better understanding of community preferences for delivery of online programs. This study aimed to assess community preferences for components, duration, frequency, modality, and setting of Internet interventions for mental health problems. A community-based online sample of 438 Australian adults was recruited using social media advertising and administered an online survey on preferences for delivery of Internet interventions, along with scales assessing potential correlates of these preferences. Participants reported a preference for briefer sessions, although they recognized a trade-off between duration and frequency of delivery. No clear preference for the modality of delivery emerged, although a clear majority preferred tailored programs. Participants preferred to access programs through a computer rather than a mobile device. Although most participants reported that they would seek help for a mental health problem, more participants had a preference for face-to-face sources only than online programs only. Younger, female, and more educated participants were significantly more likely to prefer Internet delivery. Adults in the community have a preference for Internet interventions with short modules that are tailored to individual needs. Individuals who are reluctant to seek face-to-face help may also avoid Internet interventions, suggesting that better implementation of existing Internet programs requires increasing acceptance of Internet interventions and identifying specific subgroups who may be resistant to seeking help. ©Philip J Batterham, Alison L Calear. Originally published in JMIR Mental Health (http://mental.jmir.org), 30.06.2017.

  7. Position-dependent correlation function from the SDSS-III Baryon Oscillation Spectroscopic Survey Data Release 10 CMASS sample

    International Nuclear Information System (INIS)

    Chiang, Chi-Ting; Wagner, Christian; Sánchez, Ariel G.; Schmidt, Fabian; Komatsu, Eiichiro

    2015-01-01

    We report on the first measurement of the three-point function with the position-dependent correlation function from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 10 CMASS sample. This new observable measures the correlation between two-point functions of galaxy pairs within different subvolumes, ξ-circumflex (ř,ř L ), where ř L is the location of a subvolume, and the corresponding mean overdensities, δ-bar (ř L ). This correlation, which we call the 'integrated three-point function', iζ(r)≡(ξ-circumflex (ř,ř L )δ-bar (ř L )), measures a three-point function of two short- and one long-wavelength modes, and is generated by nonlinear gravitational evolution and possibly also by the physics of inflation. The iζ(r) measured from the BOSS data lies within the scatter of those from the mock galaxy catalogs in redshift space, yielding a ten-percent-level determination of the amplitude of iζ(r). The tree-level perturbation theory in redshift space predicts how this amplitude depends on the linear and quadratic nonlinear galaxy bias parameters (b 1 and b 2 ), as well as on the amplitude and linear growth rate of matter fluctuations (σ 8 and f). Combining iζ(r) with the constraints on b 1σ 8 and fσ 8 from the global two-point correlation function and that on σ 8 from the weak lensing signal of BOSS galaxies, we measure b 2 =0.41±0.41 (68% C.L.) assuming standard perturbation theory at the tree level and the local bias model

  8. Prevalence and Risk Factors of Dengue Infection in Khanh Hoa Province, Viet Nam: A Stratified Cluster Sampling Survey.

    Science.gov (United States)

    Mai, Vien Quang; Mai, Trịnh Thị Xuan; Tam, Ngo Le Minh; Nghia, Le Trung; Komada, Kenichi; Murakami, Hitoshi

    2018-05-19

    Dengue is a clinically important arthropod-borne viral disease with increasing global incidence. Here we aimed to estimate the prevalence of dengue infections in Khanh Hoa Province, central Viet Nam, and to identify risk factors for infection. We performed a stratified cluster sampling survey including residents of 3-60 years of age in Nha Trang City, Ninh Hoa District and Dien Khanh District, Khanh Hoa Province, in October 2011. Immunoglobulin G (IgG) and immunoglobulin M (IgM) against dengue were analyzed using a rapid test kit. Participants completed a questionnaire exploring clinical dengue incidence, socio-economic status, and individual behavior. A household checklist was used to examine environment, mosquito larvae presence, and exposure to public health interventions. IgG positivity was 20.5% (urban, 16.3%; rural, 23.0%), IgM positivity was 6.7% (urban, 6.4%; rural, 6.9%), and incidence of clinically compatible dengue during the prior 3 months was 2.8 per 1,000 persons (urban, 1.7; rural, 3.4). For IgG positivity, the adjusted odds ratio (AOR) was 2.68 (95% confidence interval [CI], 1.24-5.81) for mosquito larvae presence in water pooled in old tires and was 3.09 (95% CI, 1.75-5.46) for proximity to a densely inhabited area. For IgM positivity, the AOR was 3.06 (95% CI, 1.50-6.23) for proximity to a densely inhabited area. Our results indicated rural penetration of dengue infections. Control measures should target densely inhabited areas, and may include clean-up of discarded tires and water-collecting waste.

  9. INFRARED SPECTRA AND PHOTOMETRY OF COMPLETE SAMPLES OF PALOMAR-GREEN AND TWO MICRON ALL SKY SURVEY QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yong [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Rieke, G. H.; Su, K. Y. L. [Department of Astronomy And Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Ogle, P. M. [Infrared Processing and Analysis Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Balog, Z., E-mail: yshipku@gmail.com [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-10-01

    As a step toward a comprehensive overview of the infrared (IR) diagnostics of the central engines and host galaxies of quasars at low redshift, we present Spitzer Space Telescope spectroscopic (5-40 μm) and photometric (24, 70, and 160 μm) measurements of all Palomar-Green (PG) quasars at z < 0.5 and Two Micron All Sky Survey (2MASS) quasars at z < 0.3. We supplement these data with Herschel measurements at 160 μm. The sample is composed of 87 optically selected PG quasars and 52 near-IR-selected 2MASS quasars. Here we present the data, measure the prominent spectral features, and separate emission due to star formation from that emitted by the dusty circumnuclear torus. We find that the mid-IR (5-30 μm) spectral shape for the torus is largely independent of quasar IR luminosity with scatter in the spectral energy distribution (SED) shape of ≲0.2 dex. Except for the silicate features, no large difference is observed between PG (unobscured—silicate emission) and 2MASS (obscured—silicate absorption) quasars. Only mild silicate features are observed in both cases. When in emission, the peak wavelength of the silicate feature tends to be longer than 9.7 μm, possibly indicating effects on grain properties near the active galactic nucleus. The IR color is shown to correlate with the equivalent width of the aromatic features, indicating that the slope of the quasar mid- to far-IR SED is to first order driven by the fraction of radiation from star formation in the IR bands.

  10. A COMPARATIVE ANALYSIS OF THE SUPERNOVA LEGACY SURVEY SAMPLE WITH ΛCDM AND THE Rh=ct UNIVERSE

    International Nuclear Information System (INIS)

    Wei, Jun-Jie; Wu, Xue-Feng; Melia, Fulvio; Maier, Robert S.

    2015-01-01

    The use of Type Ia supernovae (SNe Ia) has thus far produced the most reliable measurement of the expansion history of the universe, suggesting that ΛCDM offers the best explanation for the redshift–luminosity distribution observed in these events. However, analysis of other kinds of sources, such as cosmic chronometers, gamma-ray bursts, and high-z quasars, conflicts with this conclusion, indicating instead that the constant expansion rate implied by the R h = ct universe is a better fit to the data. The central difficulty with the use of SNe Ia as standard candles is that one must optimize three or four nuisance parameters characterizing supernova (SN) luminosities simultaneously with the parameters of an expansion model. Hence, in comparing competing models, one must reduce the data independently for each. We carry out such a comparison of ΛCDM and the R h = ct universe using the SN Legacy Survey sample of 252 SN events, and show that each model fits its individually reduced data very well. However, since R h = ct has only one free parameter (the Hubble constant), it follows from a standard model selection technique that it is to be preferred over ΛCDM, the minimalist version of which has three (the Hubble constant, the scaled matter density, and either the spatial curvature constant or the dark energy equation-of-state parameter). We estimate using the Bayes Information Criterion that in a pairwise comparison, the likelihood of R h = ct is ∼90%, compared with only ∼10% for a minimalist form of ΛCDM, in which dark energy is simply a cosmological constant. Compared to R h = ct, versions of the standard model with more elaborate parametrizations of dark energy are judged to be even less likely

  11. Mental health and resiliency following 44 months of terrorism: a survey of an Israeli national representative sample

    Science.gov (United States)

    Bleich, Avi; Gelkopf, Marc; Melamed, Yuval; Solomon, Zahava

    2006-01-01

    Background Israeli citizens have been exposed to intense and ongoing terrorism since September 2000. We previously studied the mental health impact of terrorism on the Israeli population (Bleich et al., 2002), however the long-term impact of ongoing terrorism has not yet been examined. The present study evaluated the psychological sequelae of 44 months of terrorism in Israel, and sought to identify factors that may contribute to vulnerability and resilience. Methods This was a telephone survey using strata sampling of 828 households, which reached a representative sample of 702 adult Israeli residents (84.8% contact rate). In total, 501 people (60.5%) agreed to participate. The methodology was similar to that of our previous study. Exposure to terrorism and other traumatic events, number of traumatic stress-related symptoms (TSRS), percentage of respondents with symptom criteria for post-traumatic stress disorder (PTSD), traumatic stress (TS) resiliency and feelings of depression, anxiety, optimism, sense of safety, and help-seeking were the main outcome measures. Results In total, 56 participants (11.2%) were directly exposed to a terrorist incident, and 101 (20.2%) had family members or friends exposed. Respondents reported a mean ± SD of 5.0 ± 4.5 TSRS; 45 (9%) met symptom criteria for PTSD; and 72 (14.4%) were TS-resilient. There were 147 participants (29.5%) who felt depressed, 50 (10.4%) felt anxious, and almost half (235; 47%) felt life-threatening danger; 48 (9.7%) felt the need for professional help. Women and people of Arab ethnicity had more TSRS, more PTSD, and less TS resiliency. Injury following a life-threatening experience, a major stressful life event, and a major loss of income were associated with PTSD. Immigrant status, lower education, low sense of safety, low sense of social support, high societal distress, and injury following life-threatening experiences were associated with TSRS. TSRS did not increase with exposure severity. This study

  12. [Sampling and measurement methods of the protocol design of the China Nine-Province Survey for blindness, visual impairment and cataract surgery].

    Science.gov (United States)

    Zhao, Jia-liang; Wang, Yu; Gao, Xue-cheng; Ellwein, Leon B; Liu, Hu

    2011-09-01

    To design the protocol of the China nine-province survey for blindness, visual impairment and cataract surgery to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery. The protocol design was began after accepting the task for the national survey for blindness, visual impairment and cataract surgery from the Department of Medicine, Ministry of Health, China, in November, 2005. The protocol in Beijing Shunyi Eye Study in 1996 and Guangdong Doumen County Eye Study in 1997, both supported by World Health Organization, was taken as the basis for the protocol design. The relative experts were invited to discuss and prove the draft protocol. An international advisor committee was established to examine and approve the draft protocol. Finally, the survey protocol was checked and approved by the Department of Medicine, Ministry of Health, China and Prevention Program of Blindness and Deafness, WHO. The survey protocol was designed according to the characteristics and the scale of the survey. The contents of the protocol included determination of target population and survey sites, calculation of the sample size, design of the random sampling, composition and organization of the survey teams, determination of the examinee, the flowchart of the field work, survey items and methods, diagnostic criteria of blindness and moderate and sever visual impairment, the measures of the quality control, the methods of the data management. The designed protocol became the standard and practical protocol for the survey to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery.

  13. Brownian distance covariance

    OpenAIRE

    Székely, Gábor J.; Rizzo, Maria L.

    2010-01-01

    Distance correlation is a new class of multivariate dependence coefficients applicable to random vectors of arbitrary and not necessarily equal dimension. Distance covariance and distance correlation are analogous to product-moment covariance and correlation, but generalize and extend these classical bivariate measures of dependence. Distance correlation characterizes independence: it is zero if and only if the random vectors are independent. The notion of covariance with...

  14. Rapid Active Sampling Surveys as a Tool to Evaluate Factors Associated with Acute Gastroenteritis and Norovirus Infection among Children in Rural Guatemala.

    Science.gov (United States)

    Olson, Daniel; Lamb, Molly M; Lopez, Maria R; Paniagua-Avila, Maria A; Zacarias, Alma; Samayoa-Reyes, Gabriela; Cordon-Rosales, Celia; Asturias, Edwin J

    2017-09-01

    We examined burden and factors associated with norovirus (NoV) acute gastroenteritis (AGE) among children in rural Guatemala. Children age 6 weeks to 17 years were enrolled into three AGE surveillance groups, using two-stage cluster sampling: a prospective participatory syndromic surveillance (PSS) cohort and two cross-sectional rapid active sampling (RAS) surveys, conducted from April 2015 to February 2016. Epidemiologic and NoV testing data were used to identify factors associated with NoV infection, AGE, and NoV+ AGE. The three cross-sectional surveys (PSS enrollment visit, RAS Survey 1, and RAS Survey 2) enrolled 1,239 children, who reported 134 (11%) AGE cases, with 20% of AGE and 11% of non-AGE samples positive for NoV. Adjusted analyses identified several modifiable factors associated with AGE and NoV infection. The cross-sectional RAS surveys were practical and cost-effective in identifying population-level risk factors for AGE and NoV, supporting their use as a tool to direct limited public health resources toward high-risk populations.

  15. A spectroscopic survey of the youngest field stars in the solar neighborhood . II. The optically faint sample

    Science.gov (United States)

    Frasca, A.; Guillout, P.; Klutsch, A.; Ferrero, R. Freire; Marilli, E.; Biazzo, K.; Gandolfi, D.; Montes, D.

    2018-05-01

    Context. Star formation in the solar neighborhood is mainly traced by young stars in open clusters, associations, and in the field, which can be identified, for example, by their X-ray emission. The determination of stellar parameters for the optical counterparts of X-ray sources is crucial for a full characterization of these stars. Aims: This work extends the spectroscopic study of the RasTyc sample, obtained by the cross-correlation of the Tycho and ROSAT All-Sky Survey catalogs, to stars fainter than V = 9.5 mag and aims to identify sparse populations of young stars in the solar neighborhood. Methods: We acquired 625 high-resolution spectra for 443 presumably young stars with four different instruments in the northern hemisphere. The radial and rotational velocity (vsini) of our targets were measured by means of the cross-correlation technique, which is also helpful to discover single-lined (SB1), double-lined spectroscopic binaries (SB2), and multiple systems. We used the code ROTFIT to perform an MK spectral classification and to determine the atmospheric parameters (Teff, logg, [Fe/H]) and vsini of the single stars and SB1 systems. For these objects, we used the spectral subtraction of slowly rotating templates to measure the equivalent widths of the Hα and Li I 6708 Å lines, which enabled us to derive their chromospheric activity level and lithium abundance. We made use of Gaia DR1 parallaxes and proper motions to locate the targets in the Hertzsprung-Russell (HR) diagram and to compute the space velocity components of the youngest objects. Results: We find a remarkable percentage (at least 35%) of binaries and multiple systems. On the basis of the lithium abundance, the sample of single stars and SB1 systems appears to be mostly ( 60%) composed of stars younger than the members of the UMa cluster. The remaining sources are in the age range between the UMa and Hyades clusters ( 20%) or older ( 20%). In total, we identify 42 very young (PMS-like) stars

  16. The effect of weak lensing on distance estimates from supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mathew; Maartens, Roy [Department of Physics, University of the Western Cape, Cape Town 7535 (South Africa); Bacon, David J.; Nichol, Robert C.; Campbell, Heather; D' Andrea, Chris B. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Clarkson, Chris [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa); Bassett, Bruce A. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Cinabro, David [Wayne State University, Department of Physics and Astronomy, Detroit, MI 48202 (United States); Finley, David A.; Frieman, Joshua A. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Galbany, Lluis [CENTRA Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Olmstead, Matthew D. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Shapiro, Charles [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, La Canada Flintridge, CA 91109 (United States); Sollerman, Jesper, E-mail: matsmith2@gmail.com [The Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden)

    2014-01-01

    Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line of sight. We find that the correlation between this measurement and the Hubble residuals is consistent with the prediction from lensing (at a significance of 1.7σ). Strong correlations are also found between the residuals and supernova nuisance parameters after a linear correction is applied. When these other correlations are taken into account, the lensing signal is detected at 1.4σ. We show, for the first time, that distance estimates from supernovae can be improved when lensing is incorporated, by including a new parameter in the SALT2 methodology for determining distance moduli. The recovered value of the new parameter is consistent with the lensing prediction. Using cosmic microwave background data from WMAP7, H {sub 0} data from Hubble Space Telescope and Sloan Digital Sky Survey (SDSS) Baryon acoustic oscillations measurements, we find the best-fit value of the new lensing parameter and show that the central values and uncertainties on Ω {sub m} and w are unaffected. The lensing of supernovae, while only seen at marginal significance in this low-redshift sample, will be of vital importance for the next generation of surveys, such as DES and LSST, which will be systematics-dominated.

  17. Obscured AGN at z similar to 1 from the zCOSMOS-Bright Survey : I. Selection and optical properties of a [Ne v]-selected sample

    NARCIS (Netherlands)

    Mignoli, M.; Vignali, C.; Gilli, R.; Comastri, A.; Zamorani, G.; Bolzonella, M.; Bongiorno, A.; Lamareille, F.; Nair, P.; Pozzetti, L.; Lilly, S. J.; Carollo, C. M.; Contini, T.; Kneib, J. -P.; Le Fevre, O.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Bardelli, S.; Caputi, K.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovac, K.; Le Borgne, J. -F.; Le Brun, V.; Maier, C.; Pello, R.; Peng, Y.; Montero, E. Perez; Presotto, V.; Silverman, J. D.; Tanaka, M.; Tasca, L.; Tresse, L.; Vergani, D.; Zucca, E.; Bordoloi, R.; Cappi, A.; Cimatti, A.; Koekemoer, A. M.; McCracken, H. J.; Moresco, M.; Welikala, N.

    Aims. The application of multi-wavelength selection techniques is essential for obtaining a complete and unbiased census of active galactic nuclei (AGN). We present here a method for selecting z similar to 1 obscured AGN from optical spectroscopic surveys. Methods. A sample of 94 narrow-line AGN

  18. National-scale vegetation change across Britain; an analysis of sample-based surveillance data from the Countryside Surveys of 1990 and 1998

    NARCIS (Netherlands)

    Smart, S.M.; Clarke, R.T.; Poll, van de H.M.; Robertson, E.J.; Shield, E.R.; Bunce, R.G.H.; Maskell, L.C.

    2003-01-01

    Patterns of vegetation across Great Britain (GB) between 1990 and 1998 were quantified based on an analysis of plant species data from a total of 9596 fixed plots. Plots were established on a stratified random basis within 501 1 km sample squares located as part of the Countryside Survey of GB.

  19. Improving the collection of knowledge, attitude and practice data with community surveys: a comparison of two second-stage sampling methods.

    Science.gov (United States)

    Davis, Rosemary H; Valadez, Joseph J

    2014-12-01

    Second-stage sampling techniques, including spatial segmentation, are widely used in community health surveys when reliable household sampling frames are not available. In India, an unresearched technique for household selection is used in eight states, which samples the house with the last marriage or birth as the starting point. Users question whether this last-birth or last-marriage (LBLM) approach introduces bias affecting survey results. We conducted two simultaneous population-based surveys. One used segmentation sampling; the other used LBLM. LBLM sampling required modification before assessment was possible and a more systematic approach was tested using last birth only. We compared coverage proportions produced by the two independent samples for six malaria indicators and demographic variables (education, wealth and caste). We then measured the level of agreement between the caste of the selected participant and the caste of the health worker making the selection. No significant difference between methods was found for the point estimates of six malaria indicators, education, caste or wealth of the survey participants (range of P: 0.06 to >0.99). A poor level of agreement occurred between the caste of the health worker used in household selection and the caste of the final participant, (Κ = 0.185), revealing little association between the two, and thereby indicating that caste was not a source of bias. Although LBLM was not testable, a systematic last-birth approach was tested. If documented concerns of last-birth sampling are addressed, this new method could offer an acceptable alternative to segmentation in India. However, inter-state caste variation could affect this result. Therefore, additional assessment of last birth is required before wider implementation is recommended. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2013; all rights reserved.

  20. A Comparative Analysis of the Supernova Legacy Survey Sample With ΛCDM and the Rh=ct Universe

    Science.gov (United States)

    Wei, Jun-Jie; Wu, Xue-Feng; Melia, Fulvio; Maier, Robert S.

    2015-03-01

    The use of Type Ia supernovae (SNe Ia) has thus far produced the most reliable measurement of the expansion history of the universe, suggesting that ΛCDM offers the best explanation for the redshift-luminosity distribution observed in these events. However, analysis of other kinds of sources, such as cosmic chronometers, gamma-ray bursts, and high-z quasars, conflicts with this conclusion, indicating instead that the constant expansion rate implied by the Rh = ct universe is a better fit to the data. The central difficulty with the use of SNe Ia as standard candles is that one must optimize three or four nuisance parameters characterizing supernova (SN) luminosities simultaneously with the parameters of an expansion model. Hence, in comparing competing models, one must reduce the data independently for each. We carry out such a comparison of ΛCDM and the Rh = ct universe using the SN Legacy Survey sample of 252 SN events, and show that each model fits its individually reduced data very well. However, since Rh = ct has only one free parameter (the Hubble constant), it follows from a standard model selection technique that it is to be preferred over ΛCDM, the minimalist version of which has three (the Hubble constant, the scaled matter density, and either the spatial curvature constant or the dark energy equation-of-state parameter). We estimate using the Bayes Information Criterion that in a pairwise comparison, the likelihood of Rh = ct is ˜90%, compared with only ˜10% for a minimalist form of ΛCDM, in which dark energy is simply a cosmological constant. Compared to Rh = ct, versions of the standard model with more elaborate parametrizations of dark energy are judged to be even less likely. This work is dedicated to the memory of Prof. Tan Lu, who sadly passed away 2014 December 3. Among his many achievements, he is considered to be one of the founders of high-energy astrophysics, and a pioneer in modern cosmology, in China.

  1. Haptic Discrimination of Distance

    Science.gov (United States)

    van Beek, Femke E.; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

    2014-01-01

    While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive) and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices. PMID:25116638

  2. Haptic discrimination of distance.

    Directory of Open Access Journals (Sweden)

    Femke E van Beek

    Full Text Available While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices.

  3. Interface Simulation Distances

    Directory of Open Access Journals (Sweden)

    Pavol Černý

    2012-10-01

    Full Text Available The classical (boolean notion of refinement for behavioral interfaces of system components is the alternating refinement preorder. In this paper, we define a distance for interfaces, called interface simulation distance. It makes the alternating refinement preorder quantitative by, intuitively, tolerating errors (while counting them in the alternating simulation game. We show that the interface simulation distance satisfies the triangle inequality, that the distance between two interfaces does not increase under parallel composition with a third interface, and that the distance between two interfaces can be bounded from above and below by distances between abstractions of the two interfaces. We illustrate the framework, and the properties of the distances under composition of interfaces, with two case studies.

  4. Tourists consuming distance

    DEFF Research Database (Denmark)

    Larsen, Gunvor Riber

    The environmental impact of tourism mobility is linked to the distances travelled in order to reach a holiday destination, and with tourists travelling more and further than previously, an understanding of how the tourists view the distance they travel across becomes relevant. Based on interviews...... contribute to an understanding of how it is possible to change tourism travel behaviour towards becoming more sustainable. How tourists 'consume distance' is discussed, from the practical level of actually driving the car or sitting in the air plane, to the symbolic consumption of distance that occurs when...... travelling on holiday becomes part of a lifestyle and a social positioning game. Further, different types of tourist distance consumers are identified, ranging from the reluctant to the deliberate and nonchalant distance consumers, who display very differing attitudes towards the distance they all travel...

  5. Marine mammal surveys in Dutch waters in 2013

    NARCIS (Netherlands)

    Geelhoed, S.C.V.; Scheidat, M.; Bemmelen, van R.S.A.

    2014-01-01

    In March/April 2013 aerial surveys to estimate the abundance of Harbour porpoises Phocoena phocoena on the Dutch Continental Shelf were conducted. These surveys were conducted along predetermined track lines using distance sampling methods in four areas: A “Dogger Bank”, B “Offshore”, C “Frisian

  6. A random cluster survey and a convenience sample give comparable estimates of immunity to vaccine preventable diseases in children of school age in Victoria, Australia.

    Science.gov (United States)

    Kelly, Heath; Riddell, Michaela A; Gidding, Heather F; Nolan, Terry; Gilbert, Gwendolyn L

    2002-08-19

    We compared estimates of the age-specific population immunity to measles, mumps, rubella, hepatitis B and varicella zoster viruses in Victorian school children obtained by a national sero-survey, using a convenience sample of residual sera from diagnostic laboratories throughout Australia, with those from a three-stage random cluster survey. When grouped according to school age (primary or secondary school) there was no significant difference in the estimates of immunity to measles, mumps, hepatitis B or varicella. Compared with the convenience sample, the random cluster survey estimated higher immunity to rubella in samples from both primary (98.7% versus 93.6%, P = 0.002) and secondary school students (98.4% versus 93.2%, P = 0.03). Despite some limitations, this study suggests that the collection of a convenience sample of sera from diagnostic laboratories is an appropriate sampling strategy to provide population immunity data that will inform Australia's current and future immunisation policies. Copyright 2002 Elsevier Science Ltd.

  7. Assessing the Applicability of 3D Holographic Technology as an Enhanced Technology for Distance Learning

    Directory of Open Access Journals (Sweden)

    Pradeep Kalansooriya

    2015-08-01

    Full Text Available Distance learning has provided an excellent platform for students in geographically remote locations while enabling them to learn at their own pace and convenience. A number of technologies are currently being utilized to conceptualize, design, enhance and foster distance learning. Teleconferences, electronic field trips, podcasts, webinars, video conferencing and online courses are among such technologies used in providing distance learning opportunities. However limitations in those existing technologies have affected to the increase of distance learners dropout rates. As an attempt to overcome the limitations in the currently adopted distance learning practices, the study aims to utilize 3D Hologram Technology (3DHT in the Engineering discipline. 3D hologram facilitates live and life size 3D telepresence that can interact with remote audiences. A survey had been conducted, using Delphi Technique to gather data from the experts in the field to evaluate the potential of 3DHT over existing technologies. Results of the survey suggested that 3DHT as a good distance learning technology and have the potential of overcoming existing limitations. Lack of infrastructure, High initial cost of infrastructure and Lack of technical know how are the main encounters identified by the experts in the sample. It is expected to develop a classroom environment with 3DHT and to evaluate its effectiveness for the distance learning in the next stage of the study.

  8. Formerly utilized MED/AEC sites remedial action program. Radiological survey of the Middlesex Sampling Plant, Middlesex, New Jersey. Final report

    International Nuclear Information System (INIS)

    1977-11-01

    The results of a radiological survey of the former Middlesex Sampling Plant, Middlesex, New Jersey, are presented in this report. The surveyed property served as a uranium ore sampling plant during the 1940's and early 1950's. It was released for unrestricted use in 1968 following a radiological survey by the Atomic Energy Commission and is now a reserve training center for the U.S. Marine Sixth Motor Transport Battalion. The present survey was undertaken to determine whether the existing radiological status of the property is consistent with current health guidelines and radiation protection practices. The radiological survey included measurement of residual alpha and beta-gamma contamination levels, radon and radon daughter concentrations in buildings, external gamma radiation levels on the site and on adjacent property, and radium concentrations in soil on the site and on adjacent property. Surface contamination levels exceeded U.S. Nuclear Regulatory Commission (NRC) guidelines and 222 Rn concentration levels exceeded the non-occupational maximum permissible concentration MPC/sub a/ of 3 pCi/liter in some structures. These results indicate the possible need for extensive radon and radon daughter measurements in structures both onsite and offsite over periods as suggested by the U.S. Surgeon General

  9. SDSS-II SUPERNOVA SURVEY: AN ANALYSIS OF THE LARGEST SAMPLE OF TYPE IA SUPERNOVAE AND CORRELATIONS WITH HOST-GALAXY SPECTRAL PROPERTIES

    International Nuclear Information System (INIS)

    Wolf, Rachel C.; Gupta, Ravi R.; Sako, Masao; Fischer, John A.; March, Marisa C.; Fischer, Johanna-Laina; D’Andrea, Chris B.; Smith, Mathew; Kessler, Rick; Scolnic, Daniel M.; Jha, Saurabh W.; Campbell, Heather; Nichol, Robert C.; Olmstead, Matthew D.; Richmond, Michael; Schneider, Donald P.

    2016-01-01

    Using the largest single-survey sample of Type Ia supernovae (SNe Ia) to date, we study the relationship between properties of SNe Ia and those of their host galaxies, focusing primarily on correlations with Hubble residuals (HRs). Our sample consists of 345 photometrically classified or spectroscopically confirmed SNe Ia discovered as part of the SDSS-II Supernova Survey (SDSS-SNS). This analysis utilizes host-galaxy spectroscopy obtained during the SDSS-I/II spectroscopic survey and from an ancillary program on the SDSS-III Baryon Oscillation Spectroscopic Survey that obtained spectra for nearly all host galaxies of SDSS-II SN candidates. In addition, we use photometric host-galaxy properties from the SDSS-SNS data release such as host stellar mass and star formation rate. We confirm the well-known relation between HR and host-galaxy mass and find a 3.6 σ significance of a nonzero linear slope. We also recover correlations between HR and host-galaxy gas-phase metallicity and specific star formation rate as they are reported in the literature. With our large data set, we examine correlations between HR and multiple host-galaxy properties simultaneously and find no evidence of a significant correlation. We also independently analyze our spectroscopically confirmed and photometrically classified SNe Ia and comment on the significance of similar combined data sets for future surveys.

  10. THE BOSS EMISSION-LINE LENS SURVEY (BELLS). I. A LARGE SPECTROSCOPICALLY SELECTED SAMPLE OF LENS GALAXIES AT REDSHIFT {approx}0.5

    Energy Technology Data Exchange (ETDEWEB)

    Brownstein, Joel R.; Bolton, Adam S.; Pandey, Parul [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schlegel, David J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Eisenstein, Daniel J. [Harvard College Observatory, 60 Garden Street, MS 20, Cambridge, MA 02138 (United States); Kochanek, Christopher S. [Department of Astronomy and Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Connolly, Natalia [Department of Physics, Hamilton College, Clinton, NY 13323 (United States); Maraston, Claudia [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom); Seitz, Stella [University Observatory Munich, Scheinstrasse 1, 81679 Muenchen (Germany); Wake, David A. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Wood-Vasey, W. Michael [Pittsburgh Center for Particle Physics, Astrophysics, and Cosmology (PITT-PACC), Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Brinkmann, Jon [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, PA 16802 (United States); Weaver, Benjamin A. [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)

    2012-01-01

    We present a catalog of 25 definite and 11 probable strong galaxy-galaxy gravitational lens systems with lens redshifts 0.4 {approx}< z {approx}< 0.7, discovered spectroscopically by the presence of higher-redshift emission lines within the Baryon Oscillation Spectroscopic Survey (BOSS) of luminous galaxies, and confirmed with high-resolution Hubble Space Telescope (HST) images of 44 candidates. Our survey extends the methodology of the Sloan Lens Advanced Camera for Surveys survey (SLACS) to higher redshift. We describe the details of the BOSS spectroscopic candidate detections, our HST ACS image processing and analysis methods, and our strong gravitational lens modeling procedure. We report BOSS spectroscopic parameters and ACS photometric parameters for all candidates, and mass-distribution parameters for the best-fit singular isothermal ellipsoid models of definite lenses. Our sample to date was selected using only the first six months of BOSS survey-quality spectroscopic data. The full five-year BOSS database should produce a sample of several hundred strong galaxy-galaxy lenses and in combination with SLACS lenses at lower redshift, strongly constrain the redshift evolution of the structure of elliptical, bulge-dominated galaxies as a function of luminosity, stellar mass, and rest-frame color, thereby providing a powerful test for competing theories of galaxy formation and evolution.

  11. Statistical searches for microlensing events in large, non-uniformly sampled time-domain surveys: A test using palomar transient factory data

    Energy Technology Data Exchange (ETDEWEB)

    Price-Whelan, Adrian M.; Agüeros, Marcel A. [Department of Astronomy, Columbia University, 550 W 120th Street, New York, NY 10027 (United States); Fournier, Amanda P. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States); Street, Rachel [Las Cumbres Observatory Global Telescope Network, Inc., 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Ofek, Eran O. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Covey, Kevin R. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Levitan, David; Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Laher, Russ R.; Surace, Jason, E-mail: adrn@astro.columbia.edu [Spitzer Science Center, California Institute of Technology, Mail Stop 314-6, Pasadena, CA 91125 (United States)

    2014-01-20

    Many photometric time-domain surveys are driven by specific goals, such as searches for supernovae or transiting exoplanets, which set the cadence with which fields are re-imaged. In the case of the Palomar Transient Factory (PTF), several sub-surveys are conducted in parallel, leading to non-uniform sampling over its ∼20,000 deg{sup 2} footprint. While the median 7.26 deg{sup 2} PTF field has been imaged ∼40 times in the R band, ∼2300 deg{sup 2} have been observed >100 times. We use PTF data to study the trade off between searching for microlensing events in a survey whose footprint is much larger than that of typical microlensing searches, but with far-from-optimal time sampling. To examine the probability that microlensing events can be recovered in these data, we test statistics used on uniformly sampled data to identify variables and transients. We find that the von Neumann ratio performs best for identifying simulated microlensing events in our data. We develop a selection method using this statistic and apply it to data from fields with >10 R-band observations, 1.1 × 10{sup 9} light curves, uncovering three candidate microlensing events. We lack simultaneous, multi-color photometry to confirm these as microlensing events. However, their number is consistent with predictions for the event rate in the PTF footprint over the survey's three years of operations, as estimated from near-field microlensing models. This work can help constrain all-sky event rate predictions and tests microlensing signal recovery in large data sets, which will be useful to future time-domain surveys, such as that planned with the Large Synoptic Survey Telescope.

  12. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  13. Traversing psychological distance.

    Science.gov (United States)

    Liberman, Nira; Trope, Yaacov

    2014-07-01

    Traversing psychological distance involves going beyond direct experience, and includes planning, perspective taking, and contemplating counterfactuals. Consistent with this view, temporal, spatial, and social distances as well as hypotheticality are associated, affect each other, and are inferred from one another. Moreover, traversing all distances involves the use of abstraction, which we define as forming a belief about the substitutability for a specific purpose of subjectively distinct objects. Indeed, across many instances of both abstraction and psychological distancing, more abstract constructs are used for more distal objects. Here, we describe the implications of this relation for prediction, choice, communication, negotiation, and self-control. We ask whether traversing distance is a general mental ability and whether distance should replace expectancy in expected-utility theories. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The effect of sampling scheme in the survey of atmospheric deposition of heavy metals in Albania by using moss biomonitoring.

    Science.gov (United States)

    Qarri, Flora; Lazo, Pranvera; Bekteshi, Lirim; Stafilov, Trajce; Frontasyeva, Marina; Harmens, Harry

    2015-02-01

    The atmospheric deposition of heavy metals in Albania was investigated by using a carpet-forming moss species (Hypnum cupressiforme) as bioindicator. Sampling was done in the dry seasons of autumn 2010 and summer 2011. Two different sampling schemes are discussed in this paper: a random sampling scheme with 62 sampling sites distributed over the whole territory of Albania and systematic sampling scheme with 44 sampling sites distributed over the same territory. Unwashed, dried samples were totally digested by using microwave digestion, and the concentrations of metal elements were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and AAS (Cd and As). Twelve elements, such as conservative and trace elements (Al and Fe and As, Cd, Cr, Cu, Ni, Mn, Pb, V, Zn, and Li), were measured in moss samples. Li as typical lithogenic element is also included. The results reflect local emission points. The median concentrations and statistical parameters of elements were discussed by comparing two sampling schemes. The results of both sampling schemes are compared with the results of other European countries. Different levels of the contamination valuated by the respective contamination factor (CF) of each element are obtained for both sampling schemes, while the local emitters identified like iron-chromium metallurgy and cement industry, oil refinery, mining industry, and transport have been the same for both sampling schemes. In addition, the natural sources, from the accumulation of these metals in mosses caused by metal-enriched soil, associated with wind blowing soils were pointed as another possibility of local emitting factors.

  15. Numerical distance protection

    CERN Document Server

    Ziegler, Gerhard

    2011-01-01

    Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

  16. Inclusion of mobile phone numbers into an ongoing population health survey in New South Wales, Australia: design, methods, call outcomes, costs and sample representativeness.

    Science.gov (United States)

    Barr, Margo L; van Ritten, Jason J; Steel, David G; Thackway, Sarah V

    2012-11-22

    In Australia telephone surveys have been the method of choice for ongoing jurisdictional population health surveys. Although it was estimated in 2011 that nearly 20% of the Australian population were mobile-only phone users, the inclusion of mobile phone numbers into these existing landline population health surveys has not occurred. This paper describes the methods used for the inclusion of mobile phone numbers into an existing ongoing landline random digit dialling (RDD) health survey in an Australian state, the New South Wales Population Health Survey (NSWPHS). This paper also compares the call outcomes, costs and the representativeness of the resultant sample to that of the previous landline sample. After examining several mobile phone pilot studies conducted in Australia and possible sample designs (screening dual-frame and overlapping dual-frame), mobile phone numbers were included into the NSWPHS using an overlapping dual-frame design. Data collection was consistent, where possible, with the previous years' landline RDD phone surveys and between frames. Survey operational data for the frames were compared and combined. Demographic information from the interview data for mobile-only phone users, both, and total were compared to the landline frame using χ2 tests. Demographic information for each frame, landline and the mobile-only (equivalent to a screening dual frame design), and the frames combined (with appropriate overlap adjustment) were compared to the NSW demographic profile from the 2011 census using χ2 tests. In the first quarter of 2012, 3395 interviews were completed with 2171 respondents (63.9%) from the landline frame (17.6% landline only) and 1224 (36.1%) from the mobile frame (25.8% mobile only). Overall combined response, contact and cooperation rates were 33.1%, 65.1% and 72.2% respectively. As expected from previous research, the demographic profile of the mobile-only phone respondents differed most (more that were young, males, Aboriginal

  17. Mass Functions of the Active Black Holes in Distant Quasars from the Large Bright Quasar Survey, the Bright Quasar Survey, and the Color-Selected Sample of the SDSS Fall Equatorial Stripe

    DEFF Research Database (Denmark)

    Vestergaard, Marianne; Osmer, Patrick S.

    2009-01-01

    We present mass functions of distant actively accreting supermassive black holes residing in luminous quasars discovered in the Large Bright Quasar Survey, the Bright Quasar Survey, and the Fall Equatorial Stripe of the Sloan Digital Sky Survey (SDSS). The quasars cover a wide range of redshifts (0...... functions at similar redshifts based on the SDSS Data Release 3 quasar catalog presented by Vestergaard et al. We see clear evidence of cosmic downsizing in the comoving space density distribution of active black holes in the LBQS sample alone. In forthcoming papers, further analysis, comparison......, and discussion of these mass functions will be made with other existing black hole mass functions, notably that based on the SDSS DR3 quasar catalog. We present the relationships used to estimate the black hole mass based on the MgII emission line; the relations are calibrated to the Hbeta and CIV relations...

  18. Gender, Sexual Orientation, and Rape Myth Acceptance: Preliminary Findings From a Sample of Primarily LGBQ-Identified Survey Respondents.

    Science.gov (United States)

    Schulze, Corina; Koon-Magnin, Sarah

    2017-02-01

    This study is among the first to examine the relationship between sexual orientation and rape myth adherence using a nationwide survey of primarily lesbian, gay, bisexual, and queer (LGBQ) respondents (n = 184). The more established Illinois Rape Myth Acceptance Scale and a modified Male Rape Survey serve as the primary instruments to test both rape myth adherence and instrument-appropriateness. Results suggest that respondents were most likely to support myths that discredit sexual assault allegations or excuse rape as a biological imperative and least likely to support myths related to physical resistance. Consistent with previous work, men exhibited higher levels of rape myth adherence than women. Regarding sexual orientation, respondents who identified as queer consistently exhibited lower levels of rape myth adherence than respondents who identified as gay.

  19. Description of the U.S. Geological Survey's water-quality sampling and water-level monitoring program at the Hallam Nuclear Facility, August through September 1997

    International Nuclear Information System (INIS)

    1997-01-01

    A water-quality and water-level program between the US Department of Energy (USDOE) and the US Geological Survey (USGS) was re-established in August 1997 to (1) collect one set of water-quality samples from 17 of the 19 USDOE monitor wells, and (2) make five water-level measurements during a 2-month period from the 19 USDOE monitor wells at the Hallam Nuclear Facility, Hallam, Nebraska. Data from these wells are presented

  20. ORDERED WEIGHTED DISTANCE MEASURE

    Institute of Scientific and Technical Information of China (English)

    Zeshui XU; Jian CHEN

    2008-01-01

    The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.

  1. Distance-transitive graphs

    NARCIS (Netherlands)

    Cohen, A.M.; Beineke, L.W.; Wilson, R.J.; Cameron, P.J.

    2004-01-01

    In this chapter we investigate the classification of distance-transitive graphs: these are graphs whose automorphism groups are transitive on each of the sets of pairs of vertices at distance i, for i = 0, 1,.... We provide an introduction into the field. By use of the classification of finite

  2. Distance Education in Entwicklungslandern.

    Science.gov (United States)

    German Foundation for International Development, Bonn (West Germany).

    Seminar and conference reports and working papers on distance education of adults, which reflect the experiences of many countries, are presented. Contents include the draft report of the 1979 International Seminar on Distance Education held in Addis Ababa, Ethiopia, which was jointly sponsored by the United Nations Economic Commission for Africa…

  3. Encyclopedia of distances

    CERN Document Server

    Deza, Michel Marie

    2009-01-01

    Distance metrics and distances have become an essential tool in many areas of pure and applied Mathematics. This title offers both independent introductions and definitions, while at the same time making cross-referencing easy through hyperlink-like boldfaced references to original definitions.

  4. Hepatitis C bio-behavioural surveys in people who inject drugs-a systematic review of sensitivity to the theoretical assumptions of respondent driven sampling.

    Science.gov (United States)

    Buchanan, Ryan; Khakoo, Salim I; Coad, Jonathan; Grellier, Leonie; Parkes, Julie

    2017-07-11

    New, more effective and better-tolerated therapies for hepatitis C (HCV) have made the elimination of HCV a feasible objective. However, for this to be achieved, it is necessary to have a detailed understanding of HCV epidemiology in people who inject drugs (PWID). Respondent-driven sampling (RDS) can provide prevalence estimates in hidden populations such as PWID. The aims of this systematic review are to identify published studies that use RDS in PWID to measure the prevalence of HCV, and compare each study against the STROBE-RDS checklist to assess their sensitivity to the theoretical assumptions underlying RDS. Searches were undertaken in accordance with PRISMA systematic review guidelines. Included studies were English language publications in peer-reviewed journals, which reported the use of RDS to recruit PWID to an HCV bio-behavioural survey. Data was extracted under three headings: (1) survey overview, (2) survey outcomes, and (3) reporting against selected STROBE-RDS criteria. Thirty-one studies met the inclusion criteria. They varied in scale (range 1-15 survey sites) and the sample sizes achieved (range 81-1000 per survey site) but were consistent in describing the use of standard RDS methods including: seeds, coupons and recruitment incentives. Twenty-seven studies (87%) either calculated or reported the intention to calculate population prevalence estimates for HCV and two used RDS data to calculate the total population size of PWID. Detailed operational and analytical procedures and reporting against selected criteria from the STROBE-RDS checklist varied between studies. There were widespread indications that sampling did not meet the assumptions underlying RDS, which led to two studies being unable to report an estimated HCV population prevalence in at least one survey location. RDS can be used to estimate a population prevalence of HCV in PWID and estimate the PWID population size. Accordingly, as a single instrument, it is a useful tool for

  5. Association between cultural distance and migrant self-rated health

    OpenAIRE

    Detollenaere, Jens; Baert, Stijn; Willems, Sara

    2018-01-01

    Abstract: We study whether migrant health in Europe is associated with the cultural distance between their host country and country of origin. To this end, we run multilevel regression models on data merging self-rated health and social background of ae3800 migrants from the European Social Survey with an index of cultural distance based on country differences in values, norms and attitudes measured in the World Values Survey. We find that higher levels of cultural distance are associated wit...

  6. Comparative evaluation of the US Environmental Protection Agency's and the Oak Ridge Institute for Science and Education's environmental survey and site assessment program field sampling procedures

    International Nuclear Information System (INIS)

    Vitkus, T.J.; Bright, T.L.; Roberts, S.A.

    1997-10-01

    At the request of the U.S. Nuclear Regulatory Commission's (NRC's) Headquarters Office, the Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute for Science and Education (ORISE) compared the documented procedures that the U.S. Environmental Protection Agency (EPA) and ESSAP use for collecting environmental samples. The project objectives were to review both organizations' procedures applicable to collecting various sample matrices, compare the procedures for similarities and differences, and then to evaluate the reason for any identified procedural differences and their potential impact on ESSAP's sample data quality. The procedures reviewed included those for sampling surface and subsurface soil, surface and groundwater, vegetation, air, and removable surface contamination. ESSAP obtained copies of relevant EPA documents and reviewed and prepared a tabulated summary of each applicable procedure. The methods for collecting and handling each type of sample were evaluated for differences, and where these were identified, the significance and effect of the differences on analytical quality were determined. The results of the comparison showed that, overall, the procedures and methods that EPA and ESSAP use for sample collection are very similar. The number of minor differences noted were the result of restrictions or procedures necessary to ensure sample integrity and prevent the introduction of interfering compounds when samples are to be analyzed for chemical parameters. For most radio nuclide analyses, these additional procedures are not necessary. Another item noted was EPA's inclusion of steps that reduce the potential for sample cross-contamination by preparing (dressing) a location prior to collecting a sample or removing a portion of a sample prior to containerization

  7. Molecular Weights of Bovine and Porcine Heparin Samples: Comparison of Chromatographic Methods and Results of a Collaborative Survey

    Directory of Open Access Journals (Sweden)

    Sabrina Bertini

    2017-07-01

    Full Text Available In a collaborative study involving six laboratories in the USA, Europe, and India the molecular weight distributions of a panel of heparin sodium samples were determined, in order to compare heparin sodium of bovine intestinal origin with that of bovine lung and porcine intestinal origin. Porcine samples met the current criteria as laid out in the USP Heparin Sodium monograph. Bovine lung heparin samples had consistently lower average molecular weights. Bovine intestinal heparin was variable in molecular weight; some samples fell below the USP limits, some fell within these limits and others fell above the upper limits. These data will inform the establishment of pharmacopeial acceptance criteria for heparin sodium derived from bovine intestinal mucosa. The method for MW determination as described in the USP monograph uses a single, broad standard calibrant to characterize the chromatographic profile of heparin sodium on high-resolution silica-based GPC columns. These columns may be short-lived in some laboratories. Using the panel of samples described above, methods based on the use of robust polymer-based columns have been developed. In addition to the use of the USP’s broad standard calibrant for heparin sodium with these columns, a set of conditions have been devised that allow light-scattering detected molecular weight characterization of heparin sodium, giving results that agree well with the monograph method. These findings may facilitate the validation of variant chromatographic methods with some practical advantages over the USP monograph method.

  8. Molecular Weights of Bovine and Porcine Heparin Samples: Comparison of Chromatographic Methods and Results of a Collaborative Survey.

    Science.gov (United States)

    Bertini, Sabrina; Risi, Giulia; Guerrini, Marco; Carrick, Kevin; Szajek, Anita Y; Mulloy, Barbara

    2017-07-19

    In a collaborative study involving six laboratories in the USA, Europe, and India the molecular weight distributions of a panel of heparin sodium samples were determined, in order to compare heparin sodium of bovine intestinal origin with that of bovine lung and porcine intestinal origin. Porcine samples met the current criteria as laid out in the USP Heparin Sodium monograph. Bovine lung heparin samples had consistently lower average molecular weights. Bovine intestinal heparin was variable in molecular weight; some samples fell below the USP limits, some fell within these limits and others fell above the upper limits. These data will inform the establishment of pharmacopeial acceptance criteria for heparin sodium derived from bovine intestinal mucosa. The method for MW determination as described in the USP monograph uses a single, broad standard calibrant to characterize the chromatographic profile of heparin sodium on high-resolution silica-based GPC columns. These columns may be short-lived in some laboratories. Using the panel of samples described above, methods based on the use of robust polymer-based columns have been developed. In addition to the use of the USP's broad standard calibrant for heparin sodium with these columns, a set of conditions have been devised that allow light-scattering detected molecular weight characterization of heparin sodium, giving results that agree well with the monograph method. These findings may facilitate the validation of variant chromatographic methods with some practical advantages over the USP monograph method.

  9. Analysis of low birth weight and its co-variants in Bangladesh based on a sub-sample from nationally representative survey.

    Science.gov (United States)

    Khan, Jahidur Rahman; Islam, Md Mazharul; Awan, Nabil; Muurlink, Olav

    2018-03-06

    Low birth weight (LBW) remains a leading global cause of childhood morbidity and mortality. This study leverages a large national survey to determine current prevalence and socioeconomic, demographic and heath related factors associated with LBW in Bangladesh. Data from the Multiple Indicator Cluster Survey (MICS) 2012-13 of Bangladesh were analyzed. A total of 2319 women for whom contemporaneous birth weight data was available and who had a live birth in the two years preceding the survey were sampled for this study. However, this analysis only was able to take advantage of 29% of the total sample with 71% missing birth weight for newborns. The indicator, LBW (rates observed in Rajshahi (11%) and highest rates in Rangpur (28%). Education of mothers (adjusted odds ratio [AOR] 0.52, 95% confidence interval [CI] 0.39-0.68 for secondary or higher educated mother) and poor antenatal care (ANC) (AOR 1.40, 95% CI 1.04-1.90) were associated with LBW after adjusting for mother's age, parity and cluster effects. Mothers from wealthier families were less likely to give birth to an LBW infant. Further indicators that wealth continues to play a role in LBW were that place of delivery, ANC and delivery assistance by quality health workers were significantly associated with LBW. However there has been a notable fall in LBW prevalence in Bangladesh since the last comparable survey (prevalence 36%), and an evidence of possible elimination of rural/urban disparities. Low birth weight remains associated with key indicators not just of maternal poverty (notably adequate maternal education) but also markers of structural poverty in health care (notably quality ANC). Results based on this sub-sample indicate LBW is still a public health concern in Bangladesh and an integrated effort from all stakeholders should be continued and interventions based on the study findings should be devised to further reduce the risk of LBW.

  10. Ethical Considerations in HIV/AIDS Biobehavioral Surveys That Use Respondent-Driven Sampling: Illustrations From Lebanon

    Science.gov (United States)

    DeJong, Jocelyn; Mahfoud, Ziyad; Khoury, Danielle; Barbir, Farah

    2009-01-01

    Respondent-driven sampling is especially useful for reaching hidden populations and is increasingly used internationally in public health research, particularly on HIV. Respondent-driven sampling involves peer recruitment and has a dual-incentive structure: both recruiters and their peer recruits are paid. Recent literature focusing on the ethical dimensions of this method in the US context has identified integral safeguards that protect against ethical violations. We analyzed a study of 3 groups in Lebanon who are at risk for HIV (injection drug users, men who have sex with men, female sex workers) and the ethical issues that arose. More explicit attention should be given to ethical issues involved in research implementing respondent-driven sampling of at-risk populations in developing countries, where ethical review mechanisms may be weak. PMID:19608961

  11. Nonmelanoma skin cancer visits and procedure patterns in a nationally representative sample: national ambulatory medical care survey 1995-2007.

    Science.gov (United States)

    Wysong, Ashley; Linos, Eleni; Hernandez-Boussard, Tina; Arron, Sarah T; Gladstone, Hayes; Tang, Jean Y

    2013-04-01

    The rising incidence of nonmelanoma skin cancer (NMSC) is well documented, but data are limited on the number of visits and treatment patterns of NMSC in the outpatient setting. To evaluate practice and treatment patterns of NMSC in the United States over the last decade and to characterize differences according to sex, age, race, insurance type, and physician specialty. Adults with an International Classification of Diseases, Ninth Revision, diagnosis of NMSC were included in this cross-sectional survey study of the National Ambulatory Medical Care Survey between 1995 and 2007. Primary outcomes included population-adjusted NMSC visit rates and odds ratios of receiving a procedure for NMSC using logistic regression. Rates of NMSC visits increased between 1995 and 2007. The number of visits was significantly higher in men, particularly those aged 65 and older. Fifty-nine percent of NMSC visits were associated with a procedure, and the individuals associated with that visit were more likely to be male, to be seen by a dermatologist, and to have private-pay insurance. Nonmelanoma skin cancer visit rates increased from 1995 to 2007 and were higher in men than women. Visits to a dermatologist are more likely to be associated with a procedure for NMSC, and there may be discrepancies in treatment patterns based on insurance type and sex. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  12. An international comparison of the Ohio department of aging-resident satisfaction survey: applicability in a U.S. and Canadian sample.

    Science.gov (United States)

    Cooke, Heather A; Yamashita, Takashi; Brown, J Scott; Straker, Jane K; Baiton Wilkinson, Susan

    2013-12-01

    The majority of resident satisfaction surveys available for use in assisted living settings have been developed in the United States; however, empirical assessment of their measurement properties remains limited and sporadic, as does knowledge regarding their applicability for use in settings outside of the United States. This study further examines the psychometric properties of the Ohio Department of Aging-Resident Satisfaction Survey (ODA-RSS) and explores its applicability within a sample of Canadian assisted living facilities. Data were collected from 9,739 residential care facility (RCF) residents in Ohio, United States and 938 assisted-living residents in British Columbia, Canada. Confirmatory factor analysis was used to assess the instrument's psychometric properties within the 2 samples. Although the ODA-RSS appears well suited for assessing resident satisfaction in Ohio RCFs, it is less so in British Columbia assisted living settings. Adequate reliability and validity were observed for all 8 measurable instrument domains in the Ohio sample, but only 4 (Care and Services, Employee Relations, Employee Responsiveness, and Communications) in the British Columbia sample. The ODA-RSS performs best in an environment that encompasses a wide range of RCF types. In settings where greater uniformity and standardization exist, more nuanced questions may be required to detect variation between facilities. It is not sufficient to assume that rigorous development and empirical testing of a tool ensures its applicability in states or countries other than that in which it was initially developed.

  13. Galaxies Gather at Great Distances

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Distant Galaxy Cluster Infrared Survey Poster [figure removed for brevity, see original site] [figure removed for brevity, see original site] Bird's Eye View Mosaic Bird's Eye View Mosaic with Clusters [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] 9.1 Billion Light-Years 8.7 Billion Light-Years 8.6 Billion Light-Years Astronomers have discovered nearly 300 galaxy clusters and groups, including almost 100 located 8 to 10 billion light-years away, using the space-based Spitzer Space Telescope and the ground-based Mayall 4-meter telescope at Kitt Peak National Observatory in Tucson, Ariz. The new sample represents a six-fold increase in the number of known galaxy clusters and groups at such extreme distances, and will allow astronomers to systematically study massive galaxies two-thirds of the way back to the Big Bang. A mosaic portraying a bird's eye view of the field in which the distant clusters were found is shown at upper left. It spans a region of sky 40 times larger than that covered by the full moon as seen from Earth. Thousands of individual images from Spitzer's infrared array camera instrument were stitched together to create this mosaic. The distant clusters are marked with orange dots. Close-up images of three of the distant galaxy clusters are shown in the adjoining panels. The clusters appear as a concentration of red dots near the center of each image. These images reveal the galaxies as they were over 8 billion years ago, since that's how long their light took to reach Earth and Spitzer's infrared eyes. These pictures are false-color composites, combining ground-based optical images captured by the Mosaic-I camera on the Mayall 4-meter telescope at Kitt Peak, with infrared pictures taken by Spitzer's infrared array camera. Blue and green represent visible light at wavelengths of 0.4 microns and 0.8 microns

  14. Motivation in Distance Leaming

    Directory of Open Access Journals (Sweden)

    Daniela Brečko

    1996-12-01

    Full Text Available It is estimated that motivation is one of the most important psychological functions making it possible for people to leam even in conditions that do not meet their needs. In distance learning, a form of autonomous learning, motivation is of outmost importance. When adopting this method in learning an individual has to stimulate himself and take learning decisions on his or her own. These specific characteristics of distance learning should be taken into account. This all different factors maintaining the motivation of partici­pants in distance learning are to be included. Moreover, motivation in distance learning can be stimulated with specific learning materials, clear instructions and guide-lines, an efficient feed back, personal contact between tutors and parti­cipants, stimulating learning letters, telephone calls, encouraging letters and through maintaining a positive relationship between tutor and participant.

  15. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical

  16. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Kougarok area, Bendeleben and Teller quadrangles, Seward Peninsula, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 302 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Kougarok River drainage as well as smaller adjacent drainages in the Bendeleben and Teller quadrangles, Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated

  17. Where on earth to publish? A sample survey comparing traditional and open access publishing in the oncological field.

    Science.gov (United States)

    Poltronieri, Elisabetta; Bravo, Elena; Camerini, Tiziana; Ferri, Maurizio; Rizzo, Roberto; Solimini, Renata; Cognetti, Gaetana

    2013-01-22

    The paper intends to help scientific authors to make the best choice of journals in which to publish, by describing and comparing journal features in the area of oncology. For this purpose, the authors identified impact factor (IF) ranking, cost options and copyright conditions offered to authors wishing to publish in full open access (OA), subscription-based or hybrid journals. Data referring to articles published in 2010 by three Italian research institutions (National Institute of Health - Rome (ISS), Regina Elena National Cancer Institute - Rome (IRE), National Cancer Institute - Milan (INT) in journals (78) managed according to different business models, all listed in the Journal Citation Reports, subject category Oncology, were collected and analysed. The journals surveyed were ranked according to IF, position in quartiles, publication charges, usage rights in published articles, self-archiving conditions in OAI-compliant repositories digital archives. Almost half (34) the journals surveyed were included in the first quartile, thus revealing authors' preference for journals with a high IF. The prevalent journal business model was the hybrid formula (based on subscriptions but also offering a paid OA option) with 51 journals, followed by subscription-based only journals accounting for 22, while just 5 full OA journals were identified. In general, no relationship was found between IF and article publication charges, in terms of correspondence between more expensive fees and higher IF. The issue of OA journals as compared with traditional subscription-based journals is highly debated among stakeholders: library administrators facing financial restrictions, authors seeking to locate the best outlet for their research, publishers wishing to increase their revenues by offering journals with wider appeal. Against this background, factors such as the quest for alternatives to high-cost business models, investments in setting up institutional repositories hosting the

  18. The association between smoking and subsequent suicide-related outcomes in the National Comorbidity Survey panel sample.

    Science.gov (United States)

    Kessler, R C; Borges, G; Sampson, N; Miller, M; Nock, M K

    2009-12-01

    Controversy exists about whether the repeatedly documented associations between smoking and subsequent suicide-related outcomes (SROs; ideation, plans, gestures and attempts) are due to unmeasured common causes or to causal effects of smoking on SROs. We address this issue by examining associations of smoking with subsequent SROs with and without controls for potential explanatory variables in the National Comorbidity Survey (NCS) panel. The latter consists of 5001 people who participated in both the 1990-2002 NCS and the 2001-2003 NCS follow-up survey. Explanatory variables include sociodemographics, potential common causes (parental history of mental-substance disorders; other respondent childhood adversities) and potential mediators (respondent history of Diagnostic and Statistical Manual of Mental Disorders, 3rd edn, revised mental-substance disorders). Small gross (that is, without controls) prospective associations are found between history of early-onset nicotine dependence and both subsequent suicide ideation and, among ideators, subsequent suicide plans. None of the baseline smoking measures, though, predicts subsequent suicide gestures or attempts among ideators. The smoking-ideation association largely disappear, but the association of early-onset nicotine dependence with subsequent suicide plans persists (odds ratio=3.0), after adjustment for control variables. However, the latter association is as strong with remitted as active nicotine dependence, arguing against a direct causal effect of nicotine dependence on suicide plans. Decomposition of the control variable effects, furthermore, suggests that these effects are due to common causes more than to mediators. These results refine our understanding of the ways in which smoking is associated with later SROs and for the most part argue against the view that these associations are due to causal effects of smoking.

  19. Einstein at a distance

    Energy Technology Data Exchange (ETDEWEB)

    Lambourne, Robert [Department of Physics and Astronomy, Open University, Milton Keynes (United Kingdom)

    2005-11-01

    This paper examines the challenges and rewards that can arise when the teaching of Einsteinian physics has to be accomplished by means of distance education. The discussion is mainly based on experiences gathered over the past 35 years at the UK Open University, where special and general relativity, relativistic cosmology and other aspects of Einsteinian physics, have been taught at a variety of levels, and using a range of techniques, to students studying at a distance.

  20. Long distance quantum teleportation

    Science.gov (United States)

    Xia, Xiu-Xiu; Sun, Qi-Chao; Zhang, Qiang; Pan, Jian-Wei

    2018-01-01

    Quantum teleportation is a core protocol in quantum information science. Besides revealing the fascinating feature of quantum entanglement, quantum teleportation provides an ultimate way to distribute quantum state over extremely long distance, which is crucial for global quantum communication and future quantum networks. In this review, we focus on the long distance quantum teleportation experiments, especially those employing photonic qubits. From the viewpoint of real-world application, both the technical advantages and disadvantages of these experiments are discussed.

  1. Methodology of the fasting sub-sample from the Mexican Health Survey, 2000 Metodología de la submuestra de suero de la Encuesta Nacional de Salud 2000

    OpenAIRE

    Simón Barquera; Citlalli Carrión; Ismael Campos; Juan Espinosa; Juan Rivera; Gustavo Olaiz-Fernández

    2007-01-01

    OBJECTIVE: To report the comparative results of the sub-sample of fasting adults selected for the biochemical measurement of cardiovascular risk factors and the rest of the Mexican Health Survey (MHS) (2000) participants. MATERIAL AND METHODS: The nationally representative, cross-sectional Mexican Health Survey (2000) was analyzed. Survey participants reporting a fasting state period of 9- to 12-h were included in a sub-sample (n= 2 535) and compared with all other participants (n= 41 126). P...

  2. Excoriation (skin-picking) disorder in adults: a cross-cultural survey of Israeli Jewish and Arab samples.

    Science.gov (United States)

    Leibovici, Vera; Koran, Lorrin M; Murad, Sari; Siam, Ihab; Odlaug, Brian L; Mandelkorn, Uri; Feldman-Weisz, Vera; Keuthen, Nancy J

    2015-04-01

    We sought to estimate the lifetime prevalence of Excoriation (Skin-Picking) Disorder (SPD) in the Israeli adult population as a whole and compare SPD prevalence in the Jewish and Arab communities. We also explored demographic, medical and psychological correlates of SPD diagnosis. Questionnaires and scales screening for SPD, and assessing the severity of perceived stress, depression, obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), alcohol use, illicit drug use, and medical disorders were completed in a sample of 2145 adults attending medical settings. The lifetime prevalence of SPD was 5.4% in the total sample; it did not differ between genders or within Jewish and Arab subsamples. Severity of depression (pcross-cultural variation in the correlates of this disorder. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Determining distances using asteroseismic methods

    DEFF Research Database (Denmark)

    Aguirre, Victor Silva; Casagrande, L.; Basu, Sarbina

    2013-01-01

    Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the r......Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification...... fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the {\\it Kepler} field that have accurate {\\it Hipparcos} parallaxes, we find agreement in our distance determinations to better than 5%. Comparison with measurements...

  4. Personality differences between users of wine, beer and spirits in a community sample: the Winnipeg Health and Drinking Survey.

    Science.gov (United States)

    McGregor, Darcy; Murray, Robert P; Barnes, Gordon E

    2003-09-01

    To date there are many studies describing the protective and risk factors associated with alcohol consumption and cardiovascular health (the U- or J-shaped curve). These studies have only accounted for part of the effects. One hypothesis is that personality differences may account for some of the unexplained variance. It is also unclear if wine, beer and distilled spirits have equivalent effects on health. The purpose of this study is to describe the differences in personality among users of wine, beer and spirits. Data were from a community sample of 1,257 men and women in Winnipeg, Manitoba, Canada, that was first enrolled in 1989-90. We examined and compared the demographic and personality characteristics of wine, beer and spirits drinkers in this sample. The groups differed significantly on the dimensions of extraversion, psychoticism and reducer-augmenter in univariate tests. In multivariate models, for the total sample and for females, predominant drinking of wine was associated with low scores on the Vando scale (augmenters). Higher consumption of beer among males was associated with higher levels of neuroticism. In these instances, personality does contribute to the characterization of groups.

  5. THE XMM-NEWTON X-RAY SPECTRA OF THE MOST X-RAY LUMINOUS RADIO-QUIET ROSAT BRIGHT SURVEY-QSOs: A REFERENCE SAMPLE FOR THE INTERPRETATION OF HIGH-REDSHIFT QSO SPECTRA

    International Nuclear Information System (INIS)

    Krumpe, M.; Markowitz, A.; Lamer, G.; Corral, A.

    2010-01-01

    We present the broadband X-ray properties of four of the most X-ray luminous (L X ≥ 10 45 erg s -1 in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe Kα fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe Kα centroids and the line widths indicate emission from neutral Fe (E = 6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at very high luminosities. Taking into account our individual EW measurements, we show that the X-ray Baldwin effect flattens above L X ∼ 10 44 erg s -1 (2-10 keV band) where an almost constant (EW) of ∼100 eV is found. We confirm the assumption of having very similar X-ray active galactic nucleus properties when interpreting stacked X-ray spectra. Our stacked spectrum serves as a superb reference for the interpretation of low S/N spectra of radio-quiet QSOs with similar luminosities at higher redshifts routinely detected by XMM-Newton and Chandra surveys.

  6. The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: structure growth rate measurement from the anisotropic quasar power spectrum in the redshift range 0.8 < z < 2.2

    Science.gov (United States)

    Gil-Marín, Héctor; Guy, Julien; Zarrouk, Pauline; Burtin, Etienne; Chuang, Chia-Hsun; Percival, Will J.; Ross, Ashley J.; Ruggeri, Rossana; Tojerio, Rita; Zhao, Gong-Bo; Wang, Yuting; Bautista, Julian; Hou, Jiamin; Sánchez, Ariel G.; Pâris, Isabelle; Baumgarten, Falk; Brownstein, Joel R.; Dawson, Kyle S.; Eftekharzadeh, Sarah; González-Pérez, Violeta; Habib, Salman; Heitmann, Katrin; Myers, Adam D.; Rossi, Graziano; Schneider, Donald P.; Seo, Hee-Jong; Tinker, Jeremy L.; Zhao, Cheng

    2018-06-01

    We analyse the clustering of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey Data Release 14 quasar sample (DR14Q). We measure the redshift space distortions using the power-spectrum monopole, quadrupole, and hexadecapole inferred from 148 659 quasars between redshifts 0.8 and 2.2, covering a total sky footprint of 2112.9 deg2. We constrain the logarithmic growth of structure times the amplitude of dark matter density fluctuations, fσ8, and the Alcock-Paczynski dilation scales that allow constraints to be placed on the angular diameter distance DA(z) and the Hubble H(z) parameter. At the effective redshift of zeff = 1.52, fσ8(zeff) = 0.420 ± 0.076, H(z_eff)=[162± 12] (r_s^fid/r_s) {km s}^{-1} Mpc^{-1}, and D_A(z_eff)=[1.85± 0.11]× 10^3 (r_s/r_s^fid) Mpc, where rs is the comoving sound horizon at the baryon drag epoch and the superscript `fid' stands for its fiducial value. The errors take into account the full error budget, including systematics and statistical contributions. These results are in full agreement with the current Λ-Cold Dark Matter cosmological model inferred from Planck measurements. Finally, we compare our measurements with other eBOSS companion papers and find excellent agreement, demonstrating the consistency and complementarity of the different methods used for analysing the data.

  7. Estimating 137Cs ingestion doses to Saamis in Kautokeino (Norway) using whole body counting vs. dietary survey results and food samples

    International Nuclear Information System (INIS)

    Skuterud, L.; Bergan, T.; Mehli, H.

    2002-01-01

    From 1965 to 1990 whole body measurements were carried out on an annual basis. Since then, 3-year cycles have been followed. In most years, the reindeer keepers have provided samples of reindeer meat for radiocaesium analysis. In 1989-1990 and 1999 dietary surveys were performed in conjunction with the whole-body monitoring. Earlier diet information is available from a separate study in 1963. Rough estimates of the radiocaesium intake by the studied population in Kautokeino have indicated that the dietary surveys have overestimated the radiocaesium intake. The aim of the present study was to evaluate the available information from Kautokeino, and to derive some conclusions regarding the reindeer meat consumption by today's reindeer keepers, and what 137 Cs ingestion doses they are exposed to. (LN)

  8. A Survey of occurrence of toxogenic fungi and mycotoxins in pig feed samples-Use in evaluation of risk assessment

    Directory of Open Access Journals (Sweden)

    Dragan Milicevic

    Full Text Available In order to assess of risk assessment, the aim of this paper was to provide good and detailed insight into the level of contamination of complete feedmixes intended for fattening swine from mycotoxin-producing fungi and mycotoxins (n=18. Isolation and quantitative enumeration of fungal propagules were done on solid media using the standard microbiological procedure. These plates were incubated the number of colonies was determined and thent on the basis of characteristic colonies and microscopic analysis was performed to identify genera and species of moulds. Isolates identified as Aspergillus and Penicillium species were subjected to molecular characterization of the presence of genes responsible for the synthesis of OTA (polyketide synthase gene-PKS. Total fungal counts (CFU/g ranged from 0,5x105 do 4x106. From a total samples analysed, seven samples had fungal counts higher than the limit established by Serbian regulations (3x105. During a mycological analysis of complete feedmixes intended for fattening swine, a total of six genera and 14 species of moulds were identified of which the most frequent one was of the genus Penicillium (94,4% while the moulds from Fusarium genere isolated in 55,5% and Paecilomyces in 44,4% of the samples from investigated localities. Other fungi from the genera Aspergillus (22%, Mycor (11,1% and Alternaria (5,5% were represented in a less amount. Polymerase chain reaction (PCR is a set of 18 isolates of the DNA belonging to families Penicillium and Aspergillus. The sequences of PCR reaction products in three samples were compared with nucleotide sequences of genes for poliketid synthase (PKS from Penicillium species and found that the samples possess PKS sequence. The traditional methods for identification of ochratoxin-producing fungi are time-consuming and labor-intensive. Rapid and specific detection of ochratoxinproducing fungi is important for ensuring microbiological quality and safety of feed and food

  9. Walking for Transportation: What do U.S. Adults Think is a Reasonable Distance and Time?

    Science.gov (United States)

    Watson, Kathleen B; Carlson, Susan A; Humbert-Rico, Tiffany; Carroll, Dianna D; Fulton, Janet E

    2015-06-16

    Less than one-third of U.S. adults walk for transportation. Public health strategies to increase transportation walking would benefit from knowing what adults think is a reasonable distance to walk. Our purpose was to determine 1) what adults think is a reasonable distance and amount of time to walk and 2) whether there were differences in minutes spent transportation walking by what adults think is reasonable. Analyses used a cross-sectional nationwide adult sample (n = 3653) participating in the 2010 Summer ConsumerStyles mail survey. Most adults (> 90%) think transportation walking is reasonable. However, less than half (43%) think walking a mile or more or for 20 minutes or more is reasonable. What adults think is reasonable is similar across most demographic subgroups, except for older adults (≥ 65 years) who think shorter distances and times are reasonable. Trend analysis that adjust for demographic characteristics indicates adults who think longer distances and times are reasonable walk more. Walking for short distances is acceptable to most U.S. adults. Public health programs designed to encourage longer distance trips may wish to improve supports for transportation walking to make walking longer distances seem easier and more acceptable to most U.S. adults.

  10. Paid employment and common mental disorders in 50-64-year olds: analysis of three cross-sectional nationally representative survey samples in 1993, 2000 and 2007.

    Science.gov (United States)

    Perera, G; Di Gessa, G; Corna, L M; Glaser, K; Stewart, R

    2017-08-24

    Associations between employment status and mental health are well recognised, but evidence is sparse on the relationship between paid employment and mental health in the years running up to statutory retirement ages using robust mental health measures. In addition, there has been no investigation into the stability over time in this relationship: an important consideration if survey findings are used to inform future policy. The aim of this study is to investigate the association between employment status and common mental disorder (CMD) in 50-64-year old residents in England and its stability over time, taking advantage of three national mental health surveys carried out over a 14-year period. Data were analysed from the British National Surveys of Psychiatric Morbidity of 1993, 2000 and 2007. Paid employment status was the primary exposure of interest and CMD the primary outcome - both ascertained identically in all three surveys (CMD from the revised Clinical Interview Schedule). Multivariable logistic regression models were used. The prevalence of CMD was higher in people not in paid employment across all survey years; however, this association was only present for non-employment related to poor health as an outcome and was not apparent in those citing other reasons for non-employment. Odds ratios for the association between non-employment due to ill health and CMD were 3.05 in 1993, 3.56 in 2000, and 2.80 in 2007, after adjustment for age, gender, marital status, education, social class, housing tenure, financial difficulties, smoking status, recent physical health consultation and activities of daily living impairment. The prevalence of CMD was higher in people not in paid employment for health reasons, but was not associated with non-employment for other reasons. Associations had been relatively stable in strength from 1993 to 2007 in those three cross-sectional nationally representative samples.

  11. Relationships between coping strategies, individual characteristics and job satisfaction in a sample of hospital nurses: cross-sectional questionnaire survey.

    Science.gov (United States)

    Golbasi, Zehra; Kelleci, Meral; Dogan, Selma

    2008-12-01

    This study aims to describe and compare the job satisfaction, coping strategies, personal and organizational characteristics among nurses working in a hospital in Turkey. In this cross-sectional survey design study, 186 nurses from Cumhuriyet University Hospital completed Personal Data Form, Minnesota Satisfaction Questionnaire and Ways of Coping Inventory. Response rate was 74.4%. In this study, it was found that job satisfaction score of nurses showed moderate (mean: 3.46+/-0.56) was found. While nurses mostly used to employ self-confident and optimistic approaches that had already being considered as positive coping strategies with stress, yielding and helpless approaches were employed less than that. While a statistically significant positive relation (pjob satisfaction and dimensions of Ways of Coping Inventory "self-confident approach" and "optimistic approach", negative relation (pjob satisfaction and dimensions of the "helpless approach". Organizational and individual nurse characteristics were not found to be associated with job satisfaction. But, job satisfaction of the nurses who is bounded by a contract was found higher than that of permanent staff nurses (pjob satisfaction of Turkish hospital nurses was at a moderate and that of the nurses who succeeded to coping with the stress was heightened. Higher levels of job satisfaction were associated with positive coping strategies. This study contributes to a growing body of evidence demonstrating the importance of coping strategies to nurses' job satisfaction.

  12. A Solution to Modeling Multilevel Confirmatory Factor Analysis with Data Obtained from Complex Survey Sampling to Avoid Conflated Parameter Estimates

    Directory of Open Access Journals (Sweden)

    Jiun-Yu Wu

    2017-09-01

    Full Text Available The issue of equality in the between-and within-level structures in Multilevel Confirmatory Factor Analysis (MCFA models has been influential for obtaining unbiased parameter estimates and statistical inferences. A commonly seen condition is the inequality of factor loadings under equal level-varying structures. With mathematical investigation and Monte Carlo simulation, this study compared the robustness of five statistical models including two model-based (a true and a mis-specified models, one design-based, and two maximum models (two models where the full rank of variance-covariance matrix is estimated in between level and within level, respectively in analyzing complex survey measurement data with level-varying factor loadings. The empirical data of 120 3rd graders' (from 40 classrooms perceived Harter competence scale were modeled using MCFA and the parameter estimates were used as true parameters to perform the Monte Carlo simulation study. Results showed maximum models was robust to unequal factor loadings while the design-based and the miss-specified model-based approaches produced conflated results and spurious statistical inferences. We recommend the use of maximum models if researchers have limited information about the pattern of factor loadings and measurement structures. Measurement models are key components of Structural Equation Modeling (SEM; therefore, the findings can be generalized to multilevel SEM and CFA models. Mplus codes are provided for maximum models and other analytical models.

  13. Gemini NIFS survey of feeding and feedback processes in nearby active galaxies - II. The sample and surface mass density profiles

    Science.gov (United States)

    Riffel, R. A.; Storchi-Bergmann, T.; Riffel, R.; Davies, R.; Bianchin, M.; Diniz, M. R.; Schönell, A. J.; Burtscher, L.; Crenshaw, M.; Fischer, T. C.; Dahmer-Hahn, L. G.; Dametto, N. Z.; Rosario, D.

    2018-02-01

    We present and characterize a sample of 20 nearby Seyfert galaxies selected for having BAT 14-195 keV luminosities LX ≥ 1041.5 erg s-1, redshift z ≤ 0.015, being accessible for observations with the Gemini Near-Infrared Field Spectrograph (NIFS) and showing extended [O III]λ5007 emission. Our goal is to study Active Galactic Nucleus (AGN) feeding and feedback processes from near-infrared integral-field spectra, which include both ionized (H II) and hot molecular (H2) emission. This sample is complemented by other nine Seyfert galaxies previously observed with NIFS. We show that the host galaxy properties (absolute magnitudes MB, MH, central stellar velocity dispersion and axial ratio) show a similar distribution to those of the 69 BAT AGN. For the 20 galaxies already observed, we present surface mass density (Σ) profiles for H II and H2 in their inner ˜500 pc, showing that H II emission presents a steeper radial gradient than H2. This can be attributed to the different excitation mechanisms: ionization by AGN radiation for H II and heating by X-rays for H2. The mean surface mass densities are in the range (0.2 ≤ ΣH II ≤ 35.9) M⊙ pc-2, and (0.2 ≤ ΣH2 ≤ 13.9)× 10-3 M⊙ pc-2, while the ratios between the H II and H2 masses range between ˜200 and 8000. The sample presented here will be used in future papers to map AGN gas excitation and kinematics, providing a census of the mass inflow and outflow rates and power as well as their relation with the AGN luminosity.

  14. Survalytics: An Open-Source Cloud-Integrated Experience Sampling, Survey, and Analytics and Metadata Collection Module for Android Operating System Apps

    Science.gov (United States)

    Mackey, Sean

    2016-01-01

    Background We describe here Survalytics, a software module designed to address two broad areas of need. The first area is in the domain of surveys and app analytics: developers of mobile apps in both academic and commercial environments require information about their users, as well as how the apps are being used, to understand who their users are and how to optimally approach app development. The second area of need is in the field of ecological momentary assessment, also referred to as experience sampling: researchers in a wide variety of fields, spanning from the social sciences to psychology to clinical medicine, would like to be able to capture daily or even more frequent data from research subjects while in their natural environment. Objective Survalytics is an open-source solution for the collection of survey responses as well as arbitrary analytic metadata from users of Android operating system apps. Methods Surveys may be administered in any combination of one-time questions and ongoing questions. The module may be deployed as a stand-alone app for experience sampling purposes or as an add-on to existing apps. The module takes advantage of free-tier NoSQL cloud database management offered by the Amazon Web Services DynamoDB platform to package a secure, flexible, extensible data collection module. DynamoDB is capable of Health Insurance Portability and Accountability Act compliant storage of personal health information. Results The provided example app may be used without modification for a basic experience sampling project, and we provide example questions for daily collection of blood glucose data from study subjects. Conclusions The module will help researchers in a wide variety of fields rapidly develop tailor-made Android apps for a variety of data collection purposes. PMID:27261155

  15. Survalytics: An Open-Source Cloud-Integrated Experience Sampling, Survey, and Analytics and Metadata Collection Module for Android Operating System Apps.

    Science.gov (United States)

    O'Reilly-Shah, Vikas; Mackey, Sean

    2016-06-03

    We describe here Survalytics, a software module designed to address two broad areas of need. The first area is in the domain of surveys and app analytics: developers of mobile apps in both academic and commercial environments require information about their users, as well as how the apps are being used, to understand who their users are and how to optimally approach app development. The second area of need is in the field of ecological momentary assessment, also referred to as experience sampling: researchers in a wide variety of fields, spanning from the social sciences to psychology to clinical medicine, would like to be able to capture daily or even more frequent data from research subjects while in their natural environment. Survalytics is an open-source solution for the collection of survey responses as well as arbitrary analytic metadata from users of Android operating system apps. Surveys may be administered in any combination of one-time questions and ongoing questions. The module may be deployed as a stand-alone app for experience sampling purposes or as an add-on to existing apps. The module takes advantage of free-tier NoSQL cloud database management offered by the Amazon Web Services DynamoDB platform to package a secure, flexible, extensible data collection module. DynamoDB is capable of Health Insurance Portability and Accountability Act compliant storage of personal health information. The provided example app may be used without modification for a basic experience sampling project, and we provide example questions for daily collection of blood glucose data from study subjects. The module will help researchers in a wide variety of fields rapidly develop tailor-made Android apps for a variety of data collection purposes.

  16. Psychosocial consequences of the Chernobyl disaster (A survey of Chernobyl accidental exposed and a non-exposed population sample)

    International Nuclear Information System (INIS)

    Havenaar, J.M.; Savelkoul, T.J.F.; Bout, J. van-den; Bootsma, P.A.

    1996-01-01

    The importance of psychological factors in the aftermath of industrial disasters is being recognized increasingly. Two field studies (total N=3084) were conducted in two regions of the former Soviet Union, to investigate the long-term psychosocial consequences of the Chernobyl nuclear power plant disaster in 1986. A sub sample of the respondents (N=449) was studied using a standardized physical and psychiatric examination. The first study took place in the Gomel region (Belarus) in the direct vicinity of the damaged nuclear plant. A control study was conducted in the Tver region (the Russian Federation), about 250 km north-west of Moscow. The results of the study indicate significantly higher levels of psychological distress, poorer subjective health and higher medical consumption in the exposed population. These findings were most prominent in risk groups such as evacuated people and mothers with children. No significant differences in overall levels of psychiatric or physical morbidity were found. Radiation related diseases could not account for the poor health perception in the investigated sample. These results indicate that psychological factors following the Chernobyl disaster had a marked effect upon psychological well being, on perceived health and on subsequent illness behavior. Fears about future health play a key role in determining this response. The provision of adequate information to the public as well as to the public health services may be important to counteract these fears

  17. Survey and visual detection of Zaire ebolavirus in clinical samples targeting the nucleoprotein gene in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Jing Yuan

    2015-12-01

    Full Text Available Ebola virus (EBOV can lead to severe hemorrhagic fever with a high risk of death in humans and other primates. To guide treatment and prevent spread of the viral infection, a rapid and sensitive detection method is required for clinical samples. Here, we described and evaluated a reverse transcription loop-mediated isothermal amplification (RT-LAMP method to detect Zaire ebolavirus using the nucleoprotein gene (NP as a target sequence. Two different techniques were used, a calcein/Mn2+ complex chromogenic method and real-time turbidity monitoring. The RT-LAMP assay detected the NP target sequence with a limit of 4.56 copies/μL within 45 min under 61°C, a similar even or increase in sensitivity than that of real-time reverse transcription-polymerase chain reaction (RT-PCR. Additionally, all pseudoviral particles or non- Zaire EBOV genomes were negative for LAMP detection, indicating that the assay was highly specific for EBOV. To appraise the availability of the RT-LAMP method for use in clinical diagnosis of EBOV, of 417 blood or swab samples collected from patients with clinically suspected infections in Sierra Leone, 307 were identified for RT-LAMP-based surveillance of EBOV. Therefore, the highly specific and sensitive RT-LAMP method allows the rapid detection of EBOV, and is a suitable tool for clinical screening, diagnosis, and primary quarantine purposes.

  18. Burden and characteristics of HIV infection among female sex workers in Kampala, Uganda - a respondent-driven sampling survey.

    Science.gov (United States)

    Hladik, Wolfgang; Baughman, Andrew L; Serwadda, David; Tappero, Jordan W; Kwezi, Rachel; Nakato, Namakula D; Barker, Joseph

    2017-06-10

    Sex workers in Uganda are at significant risk for HIV infection. We characterized the HIV epidemic among Kampala female sex workers (FSW). We used respondent-driven sampling to sample FSW aged 15+ years who reported having sold sex to men in the preceding 30 days; collected data through audio-computer assisted self-interviews, and tested blood, vaginal and rectal swabs for HIV, syphilis, neisseria gonorrhea, chlamydia trachomatis, and trichomonas vaginalis. A total of 942 FSW were enrolled from June 2008 through April 2009. The overall estimated HIV prevalence was 33% (95% confidence intervals [CI] 30%-37%) and among FSW 25 years or older was 44%. HIV infection is associated with low levels of schooling, having no other work, never having tested for HIV, self-reported genital ulcers or sores, and testing positive for neisseria gonorrhea or any sexually transmitted infections (STI). Two thirds (65%) of commercial sex acts reportedly were protected by condoms; one in five (19%) FSW reported having had anal sex. Gender-based violence was frequent; 34% reported having been raped and 24% reported having been beaten by clients in the preceding 30 days. One in three FSW in Kampala is HIV-infected, suggesting a severe HIV epidemic in this population. Intensified interventions are warranted to increase condom use, HIV testing, STI screening, as well as antiretroviral treatment and pre-exposure prophylaxis along with measures to overcome gender-based violence.

  19. Burden and characteristics of HIV infection among female sex workers in Kampala, Uganda – a respondent-driven sampling survey

    Directory of Open Access Journals (Sweden)

    Wolfgang Hladik

    2017-06-01

    Full Text Available Abstract Background Sex workers in Uganda are at significant risk for HIV infection. We characterized the HIV epidemic among Kampala female sex workers (FSW. Methods We used respondent-driven sampling to sample FSW aged 15+ years who reported having sold sex to men in the preceding 30 days; collected data through audio-computer assisted self-interviews, and tested blood, vaginal and rectal swabs for HIV, syphilis, neisseria gonorrhea, chlamydia trachomatis, and trichomonas vaginalis. Results A total of 942 FSW were enrolled from June 2008 through April 2009. The overall estimated HIV prevalence was 33% (95% confidence intervals [CI] 30%-37% and among FSW 25 years or older was 44%. HIV infection is associated with low levels of schooling, having no other work, never having tested for HIV, self-reported genital ulcers or sores, and testing positive for neisseria gonorrhea or any sexually transmitted infections (STI. Two thirds (65% of commercial sex acts reportedly were protected by condoms; one in five (19% FSW reported having had anal sex. Gender-based violence was frequent; 34% reported having been raped and 24% reported having been beaten by clients in the preceding 30 days. Conclusions One in three FSW in Kampala is HIV-infected, suggesting a severe HIV epidemic in this population. Intensified interventions are warranted to increase condom use, HIV testing, STI screening, as well as antiretroviral treatment and pre-exposure prophylaxis along with measures to overcome gender-based violence.

  20. Description of the U.S. Geological Survey's water-quality sampling and water-level monitoring program at the Hallam Nuclear Facility, June through September 1996

    International Nuclear Information System (INIS)

    1997-01-01

    A water-quality and water-level program of the US Department of Energy (USDOE) in cooperation with the US Geological Survey (USGS) was re-established in June 1996 to develop six new USDOE observation wells, collect one set of water-quality samples from 17 of the 19 USDOE observation wells, and take monthly water-level measurements for a 3-month period in all 19 USDOE observation wells at the Hallam Nuclear Facility, Hallam, Nebraska. Thirteen of the observation wells were installed by HWS Consulting Group, Inc., in June 1993 and the remaining six were installed by Applied Research Associates in August 1995