WorldWideScience

Sample records for surveys select samples

  1. 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…

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. Obscured AGN at z ~ 1 from the zCOSMOS-Bright Survey. I. Selection and optical properties of a [Ne v]-selected sample

    Science.gov (United States)

    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 Fèvre, 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.; Kovač, K.; Le Borgne, J.-F.; Le Brun, V.; Maier, C.; Pellò, R.; Peng, Y.; Perez Montero, E.; 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.

    2013-08-01

    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 ~ 1 obscured AGN from optical spectroscopic surveys. Methods: A sample of 94 narrow-line AGN with 0.65 advantage of the large amount of data available in the COSMOS field, the properties of the [Ne v]-selected type 2 AGN were investigated, focusing on their host galaxies, X-ray emission, and optical line-flux ratios. Finally, a previously developed diagnostic, based on the X-ray-to-[Ne v] luminosity ratio, was exploited to search for the more heavily obscured AGN. Results: We found that [Ne v]-selected narrow-line AGN have Seyfert 2-like optical spectra, although their emission line ratios are diluted by a star-forming component. The ACS morphologies and stellar component in the optical spectra indicate a preference for our type 2 AGN to be hosted in early-type spirals with stellar masses greater than 109.5 - 10 M⊙, on average higher than those of the galaxy parent sample. The fraction of galaxies hosting [Ne v]-selected obscured AGN increases with the stellar mass, reaching a maximum of about 3% at ≈2 × 1011 M⊙. A comparison with other selection techniques at z ~ 1, namely the line-ratio diagnostics and X-ray detections, shows that the detection of the [Ne v] λ3426 line is an effective method for selecting AGN in the optical band, in particular the most heavily obscured ones, but cannot provide a complete census of type 2 AGN by itself. Finally, the high fraction of [Ne v]-selected type 2 AGN not detected in medium-deep (≈100-200 ks) Chandra observations (67%) is suggestive of the inclusion of Compton-thick (i.e., with NH > 1024 cm-2) sources in our sample. The presence of a population of heavily obscured AGN is corroborated by the X-ray-to-[Ne v] ratio; we estimated, by means of an X-ray stacking technique and simulations, that the Compton-thick fraction in our

  11. 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...

  12. Selective information sampling

    Directory of Open Access Journals (Sweden)

    Peter A. F. Fraser-Mackenzie

    2009-06-01

    Full Text Available This study investigates the amount and valence of information selected during single item evaluation. One hundred and thirty-five participants evaluated a cell phone by reading hypothetical customers reports. Some participants were first asked to provide a preliminary rating based on a picture of the phone and some technical specifications. The participants who were given the customer reports only after they made a preliminary rating exhibited valence bias in their selection of customers reports. In contrast, the participants that did not make an initial rating sought subsequent information in a more balanced, albeit still selective, manner. The preliminary raters used the least amount of information in their final decision, resulting in faster decision times. The study appears to support the notion that selective exposure is utilized in order to develop cognitive coherence.

  13. 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

  14. 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.

  15. 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.

  16. Quick survey for detection, identification and characterization of Acanthamoeba genotypes from some selected soil and water samples in Pakistan

    Directory of Open Access Journals (Sweden)

    Tania Tanveer

    2015-05-01

    Full Text Available Acanthamoeba is an opportunistic protozoan pathogen which is widely distributed in nature and plays a pivotal role in ecosystem. Acanthamoeba species may cause blinding keratitis and fatal granulomatous encephalitis involving central nervous system. In this study, we investigated the presence of Acanthamoeba in soil and water resources of Pakistan. Here, Acanthamoeba were recovered on non-nutrient agar plate lawn with E.coli and identified by morphological characteristics of the cyst. Furthermore PCR was performed with genus-specific primers followed by direct sequencing of the PCR product for molecular identification. Overall our PCR and sequencing results confirmed pathogenic genotypes including T4 and T15 from both soil and water samples. This is our first report of Acanthamoeba isolation from both soil and water resources of Pakistan which may serve as a potential treat to human health across the country.

  17. Sample selection may bias the outcome of an adolescent mental health survey: results from a five-year follow-up of 4171 adolescents.

    Science.gov (United States)

    Kekkonen, V; Kivimäki, P; Valtonen, H; Hintikka, J; Tolmunen, T; Lehto, S M; Laukkanen, E

    2015-02-01

    The representativeness of the data is one of the main issues in evaluating the significance of research findings. Dropping out is common in adolescent mental health research, and may distort the results. Nevertheless, very little is known about the types of systematic bias that may affect studies in a) the informed consent phase and b) later in follow-up phases. The authors addressed this gap in knowledge in a five-year follow-up study on a sample of adolescents aged 13-18 years. The data were collected using self-report questionnaires. The baseline sample consisted of 4171 adolescents, 1827 (43.8%) of whom gave consent to be contacted for a follow-up survey, but only 797 (19.1%) participated in the follow-up. Binary logistic regression models were used to explain the participation. Young age, female gender, a high number of hobbies, good performance at school in the native language and general subjects, family disintegration such as divorce, high parental employment, and symptoms of depression and anxiety were associated with both consent and participation. However, the effect of mental health aspects was smaller than the effect of age and gender. This study confirmed the possibility of systematic selection bias by adolescents' sociodemographic characteristics. The representativeness of the study sample might have been improved by more intense recruitment strategies. Copyright © 2014 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  18. 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...

  19. An improved selective sampling method

    International Nuclear Information System (INIS)

    Miyahara, Hiroshi; Iida, Nobuyuki; Watanabe, Tamaki

    1986-01-01

    The coincidence methods which are currently used for the accurate activity standardisation of radio-nuclides, require dead time and resolving time corrections which tend to become increasingly uncertain as countrates exceed about 10 K. To reduce the dependence on such corrections, Muller, in 1981, proposed the selective sampling method using a fast multichannel analyser (50 ns ch -1 ) for measuring the countrates. It is, in many ways, more convenient and possibly potentially more reliable to replace the MCA with scalers and a circuit is described employing five scalers; two of them serving to measure the background correction. Results of comparisons using our new method and the coincidence method for measuring the activity of 60 Co sources yielded agree-ment within statistical uncertainties. (author)

  20. 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.

  1. 40 CFR 89.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 89.507 Sample selection. (a) Engines comprising a test sample will be selected at the location...). However, once the manufacturer ships any test engine, it relinquishes the prerogative to conduct retests...

  2. 40 CFR 90.507 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing § 90.507 Sample selection. (a) Engines comprising a test sample will be selected at the location... manufacturer ships any test engine, it relinquishes the prerogative to conduct retests as provided in § 90.508...

  3. 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

  4. 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

  5. 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.

  6. 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...

  7. 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.

  8. Variable selection and estimation for longitudinal survey data

    KAUST Repository

    Wang, Li

    2014-09-01

    There is wide interest in studying longitudinal surveys where sample subjects are observed successively over time. Longitudinal surveys have been used in many areas today, for example, in the health and social sciences, to explore relationships or to identify significant variables in regression settings. This paper develops a general strategy for the model selection problem in longitudinal sample surveys. A survey weighted penalized estimating equation approach is proposed to select significant variables and estimate the coefficients simultaneously. The proposed estimators are design consistent and perform as well as the oracle procedure when the correct submodel was known. The estimating function bootstrap is applied to obtain the standard errors of the estimated parameters with good accuracy. A fast and efficient variable selection algorithm is developed to identify significant variables for complex longitudinal survey data. Simulated examples are illustrated to show the usefulness of the proposed methodology under various model settings and sampling designs. © 2014 Elsevier Inc.

  9. 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 ...

  10. 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

  11. Sample Selection for Training Cascade Detectors.

    Science.gov (United States)

    Vállez, Noelia; Deniz, Oscar; Bueno, Gloria

    2015-01-01

    Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

  12. Sample Selection for Training Cascade Detectors.

    Directory of Open Access Journals (Sweden)

    Noelia Vállez

    Full Text Available Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

  13. 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

  14. THE TIME DOMAIN SPECTROSCOPIC SURVEY: VARIABLE SELECTION AND ANTICIPATED RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Morganson, Eric; Green, Paul J. [Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Anderson, Scott F.; Ruan, John J. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Eracleous, Michael; Brandt, William Nielsen [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Kelly, Brandon [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106-9530 (United States); Badenes, Carlos [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara St, Pittsburgh, PA 15260 (United States); Bañados, Eduardo [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Blanton, Michael R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Bershady, Matthew A. [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States); Borissova, Jura [Instituto de Física y Astronomía, Universidad de Valparaíso, Av. Gran Bretaña 1111, Playa Ancha, Casilla 5030, and Millennium Institute of Astrophysics (MAS), Santiago (Chile); Burgett, William S. [GMTO Corp, Suite 300, 251 S. Lake Ave, Pasadena, CA 91101 (United States); Chambers, Kenneth, E-mail: emorganson@cfa.harvard.edu [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); and others

    2015-06-20

    We present the selection algorithm and anticipated results for the Time Domain Spectroscopic Survey (TDSS). TDSS is an Sloan Digital Sky Survey (SDSS)-IV Extended Baryon Oscillation Spectroscopic Survey (eBOSS) subproject that will provide initial identification spectra of approximately 220,000 luminosity-variable objects (variable stars and active galactic nuclei across 7500 deg{sup 2} selected from a combination of SDSS and multi-epoch Pan-STARRS1 photometry. TDSS will be the largest spectroscopic survey to explicitly target variable objects, avoiding pre-selection on the basis of colors or detailed modeling of specific variability characteristics. Kernel Density Estimate analysis of our target population performed on SDSS Stripe 82 data suggests our target sample will be 95% pure (meaning 95% of objects we select have genuine luminosity variability of a few magnitudes or more). Our final spectroscopic sample will contain roughly 135,000 quasars and 85,000 stellar variables, approximately 4000 of which will be RR Lyrae stars which may be used as outer Milky Way probes. The variability-selected quasar population has a smoother redshift distribution than a color-selected sample, and variability measurements similar to those we develop here may be used to make more uniform quasar samples in large surveys. The stellar variable targets are distributed fairly uniformly across color space, indicating that TDSS will obtain spectra for a wide variety of stellar variables including pulsating variables, stars with significant chromospheric activity, cataclysmic variables, and eclipsing binaries. TDSS will serve as a pathfinder mission to identify and characterize the multitude of variable objects that will be detected photometrically in even larger variability surveys such as Large Synoptic Survey Telescope.

  15. Robust inference in sample selection models

    KAUST Repository

    Zhelonkin, Mikhail; Genton, Marc G.; Ronchetti, Elvezio

    2015-01-01

    The problem of non-random sample selectivity often occurs in practice in many fields. The classical estimators introduced by Heckman are the backbone of the standard statistical analysis of these models. However, these estimators are very sensitive to small deviations from the distributional assumptions which are often not satisfied in practice. We develop a general framework to study the robustness properties of estimators and tests in sample selection models. We derive the influence function and the change-of-variance function of Heckman's two-stage estimator, and we demonstrate the non-robustness of this estimator and its estimated variance to small deviations from the model assumed. We propose a procedure for robustifying the estimator, prove its asymptotic normality and give its asymptotic variance. Both cases with and without an exclusion restriction are covered. This allows us to construct a simple robust alternative to the sample selection bias test. We illustrate the use of our new methodology in an analysis of ambulatory expenditures and we compare the performance of the classical and robust methods in a Monte Carlo simulation study.

  16. Robust inference in sample selection models

    KAUST Repository

    Zhelonkin, Mikhail

    2015-11-20

    The problem of non-random sample selectivity often occurs in practice in many fields. The classical estimators introduced by Heckman are the backbone of the standard statistical analysis of these models. However, these estimators are very sensitive to small deviations from the distributional assumptions which are often not satisfied in practice. We develop a general framework to study the robustness properties of estimators and tests in sample selection models. We derive the influence function and the change-of-variance function of Heckman\\'s two-stage estimator, and we demonstrate the non-robustness of this estimator and its estimated variance to small deviations from the model assumed. We propose a procedure for robustifying the estimator, prove its asymptotic normality and give its asymptotic variance. Both cases with and without an exclusion restriction are covered. This allows us to construct a simple robust alternative to the sample selection bias test. We illustrate the use of our new methodology in an analysis of ambulatory expenditures and we compare the performance of the classical and robust methods in a Monte Carlo simulation study.

  17. The selection function of the RAVE survey

    NARCIS (Netherlands)

    Wojno, Jennifer; Kordopatis, Georges; Piffl, Tilmann; Binney, James; Steinmetz, Matthias; Matijevič, Gal; Bland-Hawthorn, Joss; Sharma, Sanjib; McMillan, Paul; Watson, Fred; Reid, Warren; Kunder, Andrea; Enke, Harry; Grebel, Eva K.; Seabroke, George; Wyse, Rosemary F. G.; Zwitter, Tomaž; Bienaymé, Olivier; Freeman, Kenneth C.; Gibson, Brad K.; Gilmore, Gerry; Helmi, Amina; Munari, Ulisse; Navarro, Julio F.; Parker, Quentin A.; Siebert, Arnaud

    2017-01-01

    We characterize the selection function of RAdial Velocity Experiment (RAVE) using 2 Micron All Sky Survey (2MASS) as our underlying population, which we assume represents all stars that could have potentially been observed. We evaluate the completeness fraction as a function of position, magnitude

  18. Privacy problems in the small sample selection

    Directory of Open Access Journals (Sweden)

    Loredana Cerbara

    2013-05-01

    Full Text Available The side of social research that uses small samples for the production of micro data, today finds some operating difficulties due to the privacy law. The privacy code is a really important and necessary law because it guarantees the Italian citizen’s rights, as already happens in other Countries of the world. However it does not seem appropriate to limit once more the possibilities of the data production of the national centres of research. That possibilities are already moreover compromised due to insufficient founds is a common problem becoming more and more frequent in the research field. It would be necessary, therefore, to include in the law the possibility to use telephonic lists to select samples useful for activities directly of interest and importance to the citizen, such as the collection of the data carried out on the basis of opinion polls by the centres of research of the Italian CNR and some universities.

  19. 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.

  20. 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.

  1. Sample size estimation and sampling techniques for selecting a representative sample

    Directory of Open Access Journals (Sweden)

    Aamir Omair

    2014-01-01

    Full Text Available Introduction: The purpose of this article is to provide a general understanding of the concepts of sampling as applied to health-related research. Sample Size Estimation: It is important to select a representative sample in quantitative research in order to be able to generalize the results to the target population. The sample should be of the required sample size and must be selected using an appropriate probability sampling technique. There are many hidden biases which can adversely affect the outcome of the study. Important factors to consider for estimating the sample size include the size of the study population, confidence level, expected proportion of the outcome variable (for categorical variables/standard deviation of the outcome variable (for numerical variables, and the required precision (margin of accuracy from the study. The more the precision required, the greater is the required sample size. Sampling Techniques: The probability sampling techniques applied for health related research include simple random sampling, systematic random sampling, stratified random sampling, cluster sampling, and multistage sampling. These are more recommended than the nonprobability sampling techniques, because the results of the study can be generalized to the target population.

  2. Mineral Composition of Selected Serbian Propolis Samples

    Directory of Open Access Journals (Sweden)

    Tosic Snezana

    2017-06-01

    Full Text Available The aim of this work was to determine the content of 22 macro- and microelements in ten raw Serbian propolis samples which differ in geographical and botanical origin as well as in polluted agent contents by atomic emission spectrometry with inductively coupled plasma (ICP-OES. The macroelements were more common and present Ca content was the highest while Na content the lowest. Among the studied essential trace elements Fe was the most common element. The levels of toxic elements (Pb, Cd, As and Hg were also analyzed, since they were possible environmental contaminants that could be transferred into propolis products for human consumption. As and Hg were not detected in any of the analyzed samples but a high level of Pb (2.0-9.7 mg/kg was detected and only selected portions of raw propolis could be used to produce natural medicines and dietary supplements for humans. Obtained results were statistically analyzed, and the examined samples showed a wide range of element content.

  3. 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

  4. Using a Calendar and Explanatory Instructions to Aid Within-Household Selection in Mail Surveys

    Science.gov (United States)

    Stange, Mathew; Smyth, Jolene D.; Olson, Kristen

    2016-01-01

    Although researchers can easily select probability samples of addresses using the U.S. Postal Service's Delivery Sequence File, randomly selecting respondents within households for surveys remains challenging. Researchers often place within-household selection instructions, such as the next or last birthday methods, in survey cover letters to…

  5. Acceptance sampling using judgmental and randomly selected samples

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-01

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

  6. 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.

  7. 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.

  8. Automated sample plan selection for OPC modeling

    Science.gov (United States)

    Casati, Nathalie; Gabrani, Maria; Viswanathan, Ramya; Bayraktar, Zikri; Jaiswal, Om; DeMaris, David; Abdo, Amr Y.; Oberschmidt, James; Krause, Andreas

    2014-03-01

    It is desired to reduce the time required to produce metrology data for calibration of Optical Proximity Correction (OPC) models and also maintain or improve the quality of the data collected with regard to how well that data represents the types of patterns that occur in real circuit designs. Previous work based on clustering in geometry and/or image parameter space has shown some benefit over strictly manual or intuitive selection, but leads to arbitrary pattern exclusion or selection which may not be the best representation of the product. Forming the pattern selection as an optimization problem, which co-optimizes a number of objective functions reflecting modelers' insight and expertise, has shown to produce models with equivalent quality to the traditional plan of record (POR) set but in a less time.

  9. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how...... causal effects might vary over individuals or groups. In this paper we point out one of the under-appreciated hazards of seeking to estimate heterogeneous causal effects: conventional selection bias (that is, selection on baseline differences) can easily be mistaken for heterogeneity of causal effects....... This might lead us to find heterogeneous effects when the true effect is homogenous, or to wrongly estimate not only the magnitude but also the sign of heterogeneous effects. We apply a test for the robustness of heterogeneous causal effects in the face of varying degrees and patterns of selection bias...

  10. Overview about bias in Customer Satisfaction Surveys and focus on self-selection error

    OpenAIRE

    Giovanna Nicolini; Luciana Dalla Valle

    2009-01-01

    The present paper provides an overview of the main types of surveys carried out for customer satisfaction analyses. In order to carry out these surveys it is possible to plan a census or select a sample. The higher the accuracy of the survey, the more reliable the results of the analysis. For this very reason, researchers pay special attention to surveys with bias due to non sampling errors, in particular to self-selection errors. These phenomena are very frequent especially in web surveys. S...

  11. 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

  12. Sample Selection for Training Cascade Detectors

    OpenAIRE

    V?llez, Noelia; Deniz, Oscar; Bueno, Gloria

    2015-01-01

    Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our a...

  13. 40 CFR 205.171-3 - Test motorcycle sample selection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test motorcycle sample selection. 205... ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycle Exhaust Systems § 205.171-3 Test motorcycle sample selection. A test motorcycle to be used for selective enforcement audit testing...

  14. Thermal properties of selected cheeses samples

    Directory of Open Access Journals (Sweden)

    Monika BOŽIKOVÁ

    2016-02-01

    Full Text Available The thermophysical parameters of selected cheeses (processed cheese and half hard cheese are presented in the article. Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms. Cheese goes during processing through the thermal and mechanical manipulation, so thermal properties are one of the most important. Knowledge about thermal parameters of cheeses could be used in the process of quality evaluation. Based on the presented facts thermal properties of selected cheeses which are produced by Slovak producers were measured. Theoretical part of article contains description of cheese and description of plane source method which was used for thermal parameters detection. Thermophysical parameters as thermal conductivity, thermal diffusivity and volume specific heat were measured during the temperature stabilisation. The results are presented as relations of thermophysical parameters to the temperature in temperature range from 13.5°C to 24°C. Every point of graphic relation was obtained as arithmetic average from measured values for the same temperature. Obtained results were statistically processed. Presented graphical relations were chosen according to the results of statistical evaluation and also according to the coefficients of determination for every relation. The results of thermal parameters are in good agreement with values measured by other authors for similar types of cheeses.

  15. 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.

  16. Radon in Finnish dwellings. Sample survey 2006

    International Nuclear Information System (INIS)

    Maekelaeinen, I.; Kinnunen, T.; Reisbacka, H.; Valmari, T.; Arvela, H.

    2009-12-01

    Indoor radon concentration was measured in 2882 dwellings randomly selected by the Population Register Centre of Finland. Radon measurements were made in two half-year periods, the first one lasting from April to November 2006 and the second one from November 2006 to April 2007. Measurements were made using STUK's alpha track detectors. According to the decree 944 / 92 by the Ministry of Social Affairs and Health, the indoor radon concentration should not exceed the 400 Bq /m 3 , whereas new buildings should be built so that 200 Bq /m 3 is not exceeded. In addition, the part D2 of the National Building Code of Finland (Indoor climate and ventilation of buildings) sets 200 Bq /m 3 as a reference value for planning of new buildings. Since 2004, according to the regulation B3 (Foundations), radon should be taken into account in new building in the whole country. A radon technical plan should be included into the building licence application. This plan can be exceptionally ignored only when building in areas where exceeding of 200 Bq / m 3 seldom occurs. In this study the nationwide means weighted by number of inhabitants in provinces in houses and flats were 121 Bq /m 3 and 49 Bq /m 3 , and 96 Bq /m 3 for all dwellings. The percentages of dwellings exceeding 200 Bq /m 3 for houses and flats were 15.1% and 1.5%, and 10.4% for all dwellings. The respective values for the reference value 400 Bq/m 3 were 3.8%, 0.7%, and 2.7%. The numbers of dwellings exceeding 200 Bq /m 3 were 204 000 for houses and 16 000 for flats, respectively. The respective numbers of dwellings exceeding 400 Bq /m 3 were 51 000 and 8.000. The highest radon concentrations were measured in the areas of Tavastia and South-Eastern Finland, in the provinces Eastern Uusimaa, Kymenlaakso, Paeijaenne Tavastia, Tavastia Proper, Pirkanmaa and South Karelia. In these provinces 29 - 51 per cent of small houses exceed 200 Bq /m 3 . The lowest radon concentrations were achieved with a crawl space foundation. Radon

  17. 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...

  18. 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...

  19. A SUCCESSFUL BROADBAND SURVEY FOR GIANT Ly{alpha} NEBULAE. I. SURVEY DESIGN AND CANDIDATE SELECTION

    Energy Technology Data Exchange (ETDEWEB)

    Prescott, Moire K. M. [Department of Physics, Broida Hall, Mail Code 9530, University of California, Santa Barbara, CA 93106 (United States); Dey, Arjun; Jannuzi, Buell T., E-mail: mkpresco@physics.ucsb.edu [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2012-04-01

    Giant Ly{alpha} nebulae (or Ly{alpha} 'blobs') are likely sites of ongoing massive galaxy formation, but the rarity of these powerful sources has made it difficult to form a coherent picture of their properties, ionization mechanisms, and space density. Systematic narrowband Ly{alpha} nebula surveys are ongoing, but the small redshift range covered and the observational expense limit the comoving volume that can be probed by even the largest of these surveys and pose a significant problem when searching for such rare sources. We have developed a systematic search technique designed to find large Ly{alpha} nebulae at 2 {approx}< z {approx}< 3 within deep broadband imaging and have carried out a survey of the 9.4 deg{sup 2} NOAO Deep Wide-Field Survey Booetes field. With a total survey comoving volume of Almost-Equal-To 10{sup 8} h{sup -3}{sub 70} Mpc{sup 3}, this is the largest volume survey for Ly{alpha} nebulae ever undertaken. In this first paper in the series, we present the details of the survey design and a systematically selected sample of 79 candidates, which includes one previously discovered Ly{alpha} nebula.

  20. Forward selection two sample binomial test

    Science.gov (United States)

    Wong, Kam-Fai; Wong, Weng-Kee; Lin, Miao-Shan

    2016-01-01

    Fisher’s exact test (FET) is a conditional method that is frequently used to analyze data in a 2 × 2 table for small samples. This test is conservative and attempts have been made to modify the test to make it less conservative. For example, Crans and Shuster (2008) proposed adding more points in the rejection region to make the test more powerful. We provide another way to modify the test to make it less conservative by using two independent binomial distributions as the reference distribution for the test statistic. We compare our new test with several methods and show that our test has advantages over existing methods in terms of control of the type 1 and type 2 errors. We reanalyze results from an oncology trial using our proposed method and our software which is freely available to the reader. PMID:27335577

  1. 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 ...

  2. 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

  3. 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.

  4. UNLABELED SELECTED SAMPLES IN FEATURE EXTRACTION FOR CLASSIFICATION OF HYPERSPECTRAL IMAGES WITH LIMITED TRAINING SAMPLES

    Directory of Open Access Journals (Sweden)

    A. Kianisarkaleh

    2015-12-01

    Full Text Available Feature extraction plays a key role in hyperspectral images classification. Using unlabeled samples, often unlimitedly available, unsupervised and semisupervised feature extraction methods show better performance when limited number of training samples exists. This paper illustrates the importance of selecting appropriate unlabeled samples that used in feature extraction methods. Also proposes a new method for unlabeled samples selection using spectral and spatial information. The proposed method has four parts including: PCA, prior classification, posterior classification and sample selection. As hyperspectral image passes these parts, selected unlabeled samples can be used in arbitrary feature extraction methods. The effectiveness of the proposed unlabeled selected samples in unsupervised and semisupervised feature extraction is demonstrated using two real hyperspectral datasets. Results show that through selecting appropriate unlabeled samples, the proposed method can improve the performance of feature extraction methods and increase classification accuracy.

  5. 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.

  6. A SUCCESSFUL BROADBAND SURVEY FOR GIANT Lyα NEBULAE. I. SURVEY DESIGN AND CANDIDATE SELECTION

    International Nuclear Information System (INIS)

    Prescott, Moire K. M.; Dey, Arjun; Jannuzi, Buell T.

    2012-01-01

    Giant Lyα nebulae (or Lyα 'blobs') are likely sites of ongoing massive galaxy formation, but the rarity of these powerful sources has made it difficult to form a coherent picture of their properties, ionization mechanisms, and space density. Systematic narrowband Lyα nebula surveys are ongoing, but the small redshift range covered and the observational expense limit the comoving volume that can be probed by even the largest of these surveys and pose a significant problem when searching for such rare sources. We have developed a systematic search technique designed to find large Lyα nebulae at 2 ∼ 2 NOAO Deep Wide-Field Survey Boötes field. With a total survey comoving volume of ≈10 8 h –3 70 Mpc 3 , this is the largest volume survey for Lyα nebulae ever undertaken. In this first paper in the series, we present the details of the survey design and a systematically selected sample of 79 candidates, which includes one previously discovered Lyα nebula.

  7. Variable selection and estimation for longitudinal survey data

    KAUST Repository

    Wang, Li; Wang, Suojin; Wang, Guannan

    2014-01-01

    There is wide interest in studying longitudinal surveys where sample subjects are observed successively over time. Longitudinal surveys have been used in many areas today, for example, in the health and social sciences, to explore relationships

  8. 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)

  9. 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.

  10. 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

  11. 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.

  12. RADIO-SELECTED QUASARS IN THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    McGreer, Ian D.; Helfand, David J.; White, Richard L.

    2009-01-01

    We have conducted a pilot survey for z > 3.5 quasars by combining the FIRST radio survey with the Sloan Digital Sky Survey (SDSS). While SDSS already targets FIRST sources for spectroscopy as quasar candidates, our survey includes fainter quasars and greatly improves the discovery rate by using strict astrometric criteria for matching the radio and optical positions. Our method allows for selection of high-redshift quasars with less color bias than with optical selection, as using radio selection essentially eliminates stellar contamination. We report the results of spectroscopy for 45 candidates, including 29 quasars in the range 0.37 3.5. We compare quasars selected using radio and optical criteria, and find that radio-selected quasars have a much higher fraction of moderately reddened objects. We derive a radio-loud quasar luminosity function at 3.5 < z < 4.0, and find that it is in good agreement with expectations from prior SDSS results.

  13. 40 CFR 205.57-2 - Test vehicle sample selection.

    Science.gov (United States)

    2010-07-01

    ... pursuant to a test request in accordance with this subpart will be selected in the manner specified in the... then using a table of random numbers to select the number of vehicles as specified in paragraph (c) of... with the desig-nated AQL are contained in Appendix I, -Table II. (c) The appropriate batch sample size...

  14. THE GROWTH OF COOL CORES AND EVOLUTION OF COOLING PROPERTIES IN A SAMPLE OF 83 GALAXY CLUSTERS AT 0.3 < z < 1.2 SELECTED FROM THE SPT-SZ SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, M.; Bautz, M. W. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Vikhlinin, A.; Stalder, B.; Ashby, M. L. N.; Bayliss, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); De Haan, T. [Department of Physics, McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8 (Canada); Lin, H. W. [Caddo Parish Magnet High School, Shrevport, LA 71101 (United States); Aird, K. A. [University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Bocquet, S.; Desai, S. [Department of Physics, Ludwig-Maximilians-Universitaet, Scheinerstr. 1, D-81679 Muenchen (Germany); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Cho, H. M. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Clocchiatti, A., E-mail: mcdonald@space.mit.edu [Departamento de Astronomia y Astrosifica, Pontificia Universidad Catolica (Chile); and others

    2013-09-01

    We present first results on the cooling properties derived from Chandra X-ray observations of 83 high-redshift (0.3 < z < 1.2) massive galaxy clusters selected by their Sunyaev-Zel'dovich signature in the South Pole Telescope data. We measure each cluster's central cooling time, central entropy, and mass deposition rate, and compare these properties to those for local cluster samples. We find no significant evolution from z {approx} 0 to z {approx} 1 in the distribution of these properties, suggesting that cooling in cluster cores is stable over long periods of time. We also find that the average cool core entropy profile in the inner {approx}100 kpc has not changed dramatically since z {approx} 1, implying that feedback must be providing nearly constant energy injection to maintain the observed ''entropy floor'' at {approx}10 keV cm{sup 2}. While the cooling properties appear roughly constant over long periods of time, we observe strong evolution in the gas density profile, with the normalized central density ({rho}{sub g,0}/{rho}{sub crit}) increasing by an order of magnitude from z {approx} 1 to z {approx} 0. When using metrics defined by the inner surface brightness profile of clusters, we find an apparent lack of classical, cuspy, cool-core clusters at z > 0.75, consistent with earlier reports for clusters at z > 0.5 using similar definitions. Our measurements indicate that cool cores have been steadily growing over the 8 Gyr spanned by our sample, consistent with a constant, {approx}150 M{sub Sun} yr{sup -1} cooling flow that is unable to cool below entropies of 10 keV cm{sup 2} and, instead, accumulates in the cluster center. We estimate that cool cores began to assemble in these massive systems at z{sub cool}=1.0{sup +1.0}{sub -0.2}, which represents the first constraints on the onset of cooling in galaxy cluster cores. At high redshift (z {approx}> 0.75), galaxy clusters may be classified as ''cooling flows

  15. 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

  16. 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

  17. 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)

  18. 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)

  19. 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.

  20. The quasar luminosity function from a variability-selected sample

    Science.gov (United States)

    Hawkins, M. R. S.; Veron, P.

    1993-01-01

    A sample of quasars is selected from a 10-yr sequence of 30 UK Schmidt plates. Luminosity functions are derived in several redshift intervals, which in each case show a featureless power-law rise towards low luminosities. There is no sign of the 'break' found in the recent UVX sample of Boyle et al. It is suggested that reasons for the disagreement are connected with biases in the selection of the UVX sample. The question of the nature of quasar evolution appears to be still unresolved.

  1. Does Self-Selection Affect Samples’ Representativeness in Online Surveys? An Investigation in Online Video Game Research

    Science.gov (United States)

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

    2014-01-01

    Background 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. Objective Our objective was to explore the representativeness of a self-selected sample of online gamers using online players’ virtual characters (avatars). Methods 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. Results 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. Conclusions 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. PMID:25001007

  2. [Potential selection bias in telephone surveys: landline and mobile phones].

    Science.gov (United States)

    Garcia-Continente, Xavier; Pérez-Giménez, Anna; López, María José; Nebot, Manel

    2014-01-01

    The increasing use of mobile phones in the last decade has decreased landline telephone coverage in Spanish households. This study aimed to analyze sociodemographic characteristics and health indicators by type of telephone service (mobile phone vs. landline or landline and mobile phone). Two telephone surveys were conducted in Spanish samples (February 2010 and February 2011). Multivariate logistic regression analyses were performed to analyze differences in the main sociodemographic characteristics and health indicators according to the type of telephone service available in Spanish households. We obtained 2027 valid responses (1627 landline telephones and 400 mobile phones). Persons contacted through a mobile phone were more likely to be a foreigner, to belong to the manual social class, to have a lower educational level, and to be a smoker than those contacted through a landline telephone. The profile of the population that has only a mobile phone differs from that with a landline telephone. Therefore, telephone surveys that exclude mobile phones could show a selection bias. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

  3. 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.

  4. 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)

  5. The genealogy of samples in models with selection.

    Science.gov (United States)

    Neuhauser, C; Krone, S M

    1997-02-01

    We introduce the genealogy of a random sample of genes taken from a large haploid population that evolves according to random reproduction with selection and mutation. Without selection, the genealogy is described by Kingman's well-known coalescent process. In the selective case, the genealogy of the sample is embedded in a graph with a coalescing and branching structure. We describe this graph, called the ancestral selection graph, and point out differences and similarities with Kingman's coalescent. We present simulations for a two-allele model with symmetric mutation in which one of the alleles has a selective advantage over the other. We find that when the allele frequencies in the population are already in equilibrium, then the genealogy does not differ much from the neutral case. This is supported by rigorous results. Furthermore, we describe the ancestral selection graph for other selective models with finitely many selection classes, such as the K-allele models, infinitely-many-alleles models. DNA sequence models, and infinitely-many-sites models, and briefly discuss the diploid case.

  6. 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

  7. Perils and potentials of self-selected entry to epidemiological studies and surveys

    DEFF Research Database (Denmark)

    Keiding, Niels; Louis, Thomas A.

    2016-01-01

    Low front-end cost and rapid accrual make Web-based surveys and enrolment in studies attractive, but participants are often self-selected with little reference to a well-defined study base. Of course, high quality studies must be internally valid (validity of inferences for the sample at hand......), but Web-based enrolment reactivates discussion of external validity (generalization of within-study inferences to a target population or context) in epidemiology and clinical trials. Survey research relies on a representative sample produced by a sampling frame, prespecified sampling process and weighting...

  8. 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...

  9. Autonomous site selection and instrument positioning for sample acquisition

    Science.gov (United States)

    Shaw, A.; Barnes, D.; Pugh, S.

    The European Space Agency Aurora Exploration Program aims to establish a European long-term programme for the exploration of Space, culminating in a human mission to space in the 2030 timeframe. Two flagship missions, namely Mars Sample Return and ExoMars, have been proposed as recognised steps along the way. The Exomars Rover is the first of these flagship missions and includes a rover carrying the Pasteur Payload, a mobile exobiology instrumentation package, and the Beagle 2 arm. The primary objective is the search for evidence of past or present life on mars, but the payload will also study the evolution of the planet and the atmosphere, look for evidence of seismological activity and survey the environment in preparation for future missions. The operation of rovers in unknown environments is complicated, and requires large resources not only on the planet but also in ground based operations. Currently, this can be very labour intensive, and costly, if large teams of scientists and engineers are required to assess mission progress, plan mission scenarios, and construct a sequence of events or goals for uplink. Furthermore, the constraints in communication imposed by the time delay involved over such large distances, and line-of-sight required, make autonomy paramount to mission success, affording the ability to operate in the event of communications outages and be opportunistic with respect to scientific discovery. As part of this drive to reduce mission costs and increase autonomy the Space Robotics group at the University of Wales, Aberystwyth is researching methods of autonomous site selection and instrument positioning, directly applicable to the ExoMars mission. The site selection technique used builds on the geometric reasoning algorithms used previously for localisation and navigation [Shaw 03]. It is proposed that a digital elevation model (DEM) of the local surface, generated during traverse and without interaction from ground based operators, can be

  10. 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.

  11. Target Selection for the SDSS-III MARVELS Survey

    Science.gov (United States)

    Paegert, Martin; Stassun, Keivan G.; De Lee, Nathan; Pepper, Joshua; Fleming, Scott W.; Sivarani, Thirupathi; Mahadevan, Suvrath; Mack, Claude E., III; Dhital, Saurav; Hebb, Leslie; Ge, Jian

    2015-06-01

    We present the target selection process for the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the Sloan Digital Sky Survey (SDSS) III. MARVELS is a medium-resolution (R ∼ 11,000) multi-fiber spectrograph capable of obtaining radial velocities for 60 objects at a time in order to find brown dwarfs and giant planets. The survey was configured to target dwarf stars with effective temperatures approximately between 4500 and 6250 K. For the first 2 years MARVELS relied on low-resolution spectroscopic pre-observations to estimate the effective temperature and log (g) for candidate stars and then selected suitable dwarf stars from this pool. Ultimately, the pre-observation spectra proved ineffective at filtering out giant stars; many giants were incorrectly classified as dwarfs, resulting in a giant contamination rate of ∼30% for the first phase of the MARVELS survey. Thereafter, the survey instead applied a reduced proper motion cut to eliminate giants and used the Infrared Flux Method to estimate effective temperatures, using only extant photmetric and proper-motion catalog information. The target selection method introduced here may be useful for other surveys that need to rely on extant catalog data for selection of specific stellar populations.

  12. Sampling point selection for energy estimation in the quasicontinuum method

    NARCIS (Netherlands)

    Beex, L.A.A.; Peerlings, R.H.J.; Geers, M.G.D.

    2010-01-01

    The quasicontinuum (QC) method reduces computational costs of atomistic calculations by using interpolation between a small number of so-called repatoms to represent the displacements of the complete lattice and by selecting a small number of sampling atoms to estimate the total potential energy of

  13. 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.)

  14. Robust online tracking via adaptive samples selection with saliency detection

    Science.gov (United States)

    Yan, Jia; Chen, Xi; Zhu, QiuPing

    2013-12-01

    Online tracking has shown to be successful in tracking of previously unknown objects. However, there are two important factors which lead to drift problem of online tracking, the one is how to select the exact labeled samples even when the target locations are inaccurate, and the other is how to handle the confusors which have similar features with the target. In this article, we propose a robust online tracking algorithm with adaptive samples selection based on saliency detection to overcome the drift problem. To deal with the problem of degrading the classifiers using mis-aligned samples, we introduce the saliency detection method to our tracking problem. Saliency maps and the strong classifiers are combined to extract the most correct positive samples. Our approach employs a simple yet saliency detection algorithm based on image spectral residual analysis. Furthermore, instead of using the random patches as the negative samples, we propose a reasonable selection criterion, in which both the saliency confidence and similarity are considered with the benefits that confusors in the surrounding background are incorporated into the classifiers update process before the drift occurs. The tracking task is formulated as a binary classification via online boosting framework. Experiment results in several challenging video sequences demonstrate the accuracy and stability of our tracker.

  15. Using maximum entropy modeling for optimal selection of sampling sites for monitoring networks

    Science.gov (United States)

    Stohlgren, Thomas J.; Kumar, Sunil; Barnett, David T.; Evangelista, Paul H.

    2011-01-01

    Environmental monitoring programs must efficiently describe state shifts. We propose using maximum entropy modeling to select dissimilar sampling sites to capture environmental variability at low cost, and demonstrate a specific application: sample site selection for the Central Plains domain (453,490 km2) of the National Ecological Observatory Network (NEON). We relied on four environmental factors: mean annual temperature and precipitation, elevation, and vegetation type. A “sample site” was defined as a 20 km × 20 km area (equal to NEON’s airborne observation platform [AOP] footprint), within which each 1 km2 cell was evaluated for each environmental factor. After each model run, the most environmentally dissimilar site was selected from all potential sample sites. The iterative selection of eight sites captured approximately 80% of the environmental envelope of the domain, an improvement over stratified random sampling and simple random designs for sample site selection. This approach can be widely used for cost-efficient selection of survey and monitoring sites.

  16. 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.

  17. Patch-based visual tracking with online representative sample selection

    Science.gov (United States)

    Ou, Weihua; Yuan, Di; Li, Donghao; Liu, Bin; Xia, Daoxun; Zeng, Wu

    2017-05-01

    Occlusion is one of the most challenging problems in visual object tracking. Recently, a lot of discriminative methods have been proposed to deal with this problem. For the discriminative methods, it is difficult to select the representative samples for the target template updating. In general, the holistic bounding boxes that contain tracked results are selected as the positive samples. However, when the objects are occluded, this simple strategy easily introduces the noises into the training data set and the target template and then leads the tracker to drift away from the target seriously. To address this problem, we propose a robust patch-based visual tracker with online representative sample selection. Different from previous works, we divide the object and the candidates into several patches uniformly and propose a score function to calculate the score of each patch independently. Then, the average score is adopted to determine the optimal candidate. Finally, we utilize the non-negative least square method to find the representative samples, which are used to update the target template. The experimental results on the object tracking benchmark 2013 and on the 13 challenging sequences show that the proposed method is robust to the occlusion and achieves promising results.

  18. Evaluation of Stress Loaded Steel Samples Using Selected Electromagnetic Methods

    International Nuclear Information System (INIS)

    Chady, T.

    2004-01-01

    In this paper the magnetic leakage flux and eddy current method were used to evaluate changes of materials' properties caused by stress. Seven samples made of ferromagnetic material with different level of applied stress were prepared. First, the leakage magnetic fields were measured by scanning the surface of the specimens with GMR gradiometer. Next, the same samples were evaluated using an eddy current sensor. A comparison between results obtained from both methods was carried out. Finally, selected parameters of the measured signal were calculated and utilized to evaluate level of the applied stress. A strong coincidence between amount of the applied stress and the maximum amplitude of the derivative was confirmed

  19. A survey of drug abuse problems among students of selected ...

    African Journals Online (AJOL)

    The purpose of the study was to survey drug abuse problems among students of selected secondary schools in Ile-Ife in Osun State. Specifically, the study was to find out the reasons for drug abuse among students. The major instrument used to collect needed information was the questionnaire which was distributed to ...

  20. A Survey of Job Loss in Selected Communities around ...

    African Journals Online (AJOL)

    A Survey of Job Loss in Selected Communities around Johannesburg, South Africa. ... They experienced a feeling of lowered self-esteem. However, although seriously afflicted by the ravages of job loss within their communities, the majority of the respondents did not express a desire to relocate to other places.

  1. 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.

  2. Estimating the residential demand function for natural gas in Seoul with correction for sample selection bias

    International Nuclear Information System (INIS)

    Yoo, Seung-Hoon; Lim, Hea-Jin; Kwak, Seung-Jun

    2009-01-01

    Over the last twenty years, the consumption of natural gas in Korea has increased dramatically. This increase has mainly resulted from the rise of consumption in the residential sector. The main objective of the study is to estimate households' demand function for natural gas by applying a sample selection model using data from a survey of households in Seoul. The results show that there exists a selection bias in the sample and that failure to correct for sample selection bias distorts the mean estimate, of the demand for natural gas, downward by 48.1%. In addition, according to the estimation results, the size of the house, the dummy variable for dwelling in an apartment, the dummy variable for having a bed in an inner room, and the household's income all have positive relationships with the demand for natural gas. On the other hand, the size of the family and the price of gas negatively contribute to the demand for natural gas. (author)

  3. 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.

  4. An Improved Nested Sampling Algorithm for Model Selection and Assessment

    Science.gov (United States)

    Zeng, X.; Ye, M.; Wu, J.; WANG, D.

    2017-12-01

    Multimodel strategy is a general approach for treating model structure uncertainty in recent researches. The unknown groundwater system is represented by several plausible conceptual models. Each alternative conceptual model is attached with a weight which represents the possibility of this model. In Bayesian framework, the posterior model weight is computed as the product of model prior weight and marginal likelihood (or termed as model evidence). As a result, estimating marginal likelihoods is crucial for reliable model selection and assessment in multimodel analysis. Nested sampling estimator (NSE) is a new proposed algorithm for marginal likelihood estimation. The implementation of NSE comprises searching the parameters' space from low likelihood area to high likelihood area gradually, and this evolution is finished iteratively via local sampling procedure. Thus, the efficiency of NSE is dominated by the strength of local sampling procedure. Currently, Metropolis-Hasting (M-H) algorithm and its variants are often used for local sampling in NSE. However, M-H is not an efficient sampling algorithm for high-dimensional or complex likelihood function. For improving the performance of NSE, it could be feasible to integrate more efficient and elaborated sampling algorithm - DREAMzs into the local sampling. In addition, in order to overcome the computation burden problem of large quantity of repeating model executions in marginal likelihood estimation, an adaptive sparse grid stochastic collocation method is used to build the surrogates for original groundwater model.

  5. The TRacking Adolescents' Individual Lives Survey (TRAILS) : Design, Current Status, and Selected Findings

    NARCIS (Netherlands)

    Ormel, Johan; Oldehinkel, Albertine J; Sijtsema, Jelle; van Oort, Floor; Raven, Dennis; Veenstra, Rene; Vollebergh, Wilma A M; Verhulst, Frank C

    2012-01-01

    Objectives: The objectives of this study were as follows: to present a concise overview of the sample, outcomes, determinants, non-response and attrition of the ongoing TRacking Adolescents' Individual Lives Survey (TRAILS), which started in 2001; to summarize a selection of recent findings on

  6. The TRacking Adolescents' Individual Lives Survey (TRAILS): Design, Current Status, and Selected Findings

    Science.gov (United States)

    Ormel, Johan; Oldehinkel, Albertine J.; Sijtsema, Jelle; van Oort, Floor; Raven, Dennis; Veenstra, Rene; Vollebergh, Wilma A. M.; Verhulst, Frank C.

    2012-01-01

    Objectives: The objectives of this study were as follows: to present a concise overview of the sample, outcomes, determinants, non-response and attrition of the ongoing TRacking Adolescents' Individual Lives Survey (TRAILS), which started in 2001; to summarize a selection of recent findings on continuity, discontinuity, risk, and protective…

  7. Selection of the Sample for Data-Driven $Z \\to \

    CERN Document Server

    Krauss, Martin

    2009-01-01

    The topic of this study was to improve the selection of the sample for data-driven Z → ν ν background estimation, which is a major contribution in supersymmetric searches in ̄ a no-lepton search mode. The data is based on Z → + − samples using data created with ATLAS simulation software. This method works if two leptons are reconstructed, but using cuts that are typical for SUSY searches reconstruction efficiency for electrons and muons is rather low. For this reason it was tried to enhance the data sample. Therefore events were considered, where only one electron was reconstructed. In this case the invariant mass for the electron and each jet was computed to select the jet with the best match for the Z boson mass as not reconstructed electron. This way the sample can be extended but significantly looses purity because of also reconstructed background events. To improve this method other variables have to be considered which were not available for this study. Applying a similar method to muons using ...

  8. Failure Probability Estimation Using Asymptotic Sampling and Its Dependence upon the Selected Sampling Scheme

    Directory of Open Access Journals (Sweden)

    Martinásková Magdalena

    2017-12-01

    Full Text Available The article examines the use of Asymptotic Sampling (AS for the estimation of failure probability. The AS algorithm requires samples of multidimensional Gaussian random vectors, which may be obtained by many alternative means that influence the performance of the AS method. Several reliability problems (test functions have been selected in order to test AS with various sampling schemes: (i Monte Carlo designs; (ii LHS designs optimized using the Periodic Audze-Eglājs (PAE criterion; (iii designs prepared using Sobol’ sequences. All results are compared with the exact failure probability value.

  9. H I-SELECTED GALAXIES IN THE SLOAN DIGITAL SKY SURVEY. I. OPTICAL DATA

    International Nuclear Information System (INIS)

    West, Andrew A.; Garcia-Appadoo, Diego A.; Dalcanton, Julianne J.; Ivezic, Zeljko; Bentz, Misty C.; Disney, Mike J.; Rockosi, Constance M.; Brinkmann, J.

    2010-01-01

    We present the optical data for 195 H I-selected galaxies that fall within both the Sloan Digital Sky Survey (SDSS) and the Parkes Equatorial Survey (ES). The photometric quantities have been independently recomputed for our sample using a new photometric pipeline optimized for large galaxies, thus correcting for SDSS's limited reliability for automatic photometry of angularly large or low surface brightness (LSB) galaxies. We outline the magnitude of the uncertainty in the SDSS catalog-level photometry and derive a quantitative method for correcting the over-sky subtraction in the SDSS photometric pipeline. The main thrust of this paper is to present the ES/SDSS sample and discuss the methods behind the improved photometry, which will be used in future scientific analysis. We present the overall optical properties of the sample and briefly compare to a volume-limited, optically selected sample. Compared to the optically selected SDSS sample (in the similar volume), H I-selected galaxies are bluer and more luminous (fewer dwarf ellipticals and more star formation). However, compared to typical SDSS galaxy studies, which have their own selection effect, our sample is bluer, fainter, and less massive.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Application of the Sampling Selection Technique in Approaching Financial Audit

    Directory of Open Access Journals (Sweden)

    Victor Munteanu

    2018-03-01

    Full Text Available In his professional approach, the financial auditor has a wide range of working techniques, including selection techniques. They are applied depending on the nature of the information available to the financial auditor, the manner in which they are presented - paper or electronic format, and, last but not least, the time available. Several techniques are applied, successively or in parallel, to increase the safety of the expressed opinion and to provide the audit report with a solid basis of information. Sampling is used in the phase of control or clarification of the identified error. The main purpose is to corroborate or measure the degree of risk detected following a pertinent analysis. Since the auditor does not have time or means to thoroughly rebuild the information, the sampling technique can provide an effective response to the need for valorization.

  15. 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.)

  16. 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.)

  17. A Uniformly Selected Sample of Low-mass Black Holes in Seyfert 1 Galaxies. II. The SDSS DR7 Sample

    Science.gov (United States)

    Liu, He-Yang; Yuan, Weimin; Dong, Xiao-Bo; Zhou, Hongyan; Liu, Wen-Juan

    2018-04-01

    A new sample of 204 low-mass black holes (LMBHs) in active galactic nuclei (AGNs) is presented with black hole masses in the range of (1–20) × 105 M ⊙. The AGNs are selected through a systematic search among galaxies in the Seventh Data Release (DR7) of the Sloan Digital Sky Survey (SDSS), and careful analyses of their optical spectra and precise measurement of spectral parameters. Combining them with our previous sample selected from SDSS DR4 makes it the largest LMBH sample so far, totaling over 500 objects. Some of the statistical properties of the combined LMBH AGN sample are briefly discussed in the context of exploring the low-mass end of the AGN population. Their X-ray luminosities follow the extension of the previously known correlation with the [O III] luminosity. The effective optical-to-X-ray spectral indices α OX, albeit with a large scatter, are broadly consistent with the extension of the relation with the near-UV luminosity L 2500 Å. Interestingly, a correlation of α OX with black hole mass is also found, with α OX being statistically flatter (stronger X-ray relative to optical) for lower black hole masses. Only 26 objects, mostly radio loud, were detected in radio at 20 cm in the FIRST survey, giving a radio-loud fraction of 4%. The host galaxies of LMBHs have stellar masses in the range of 108.8–1012.4 M ⊙ and optical colors typical of Sbc spirals. They are dominated by young stellar populations that seem to have undergone continuous star formation history.

  18. Effective traffic features selection algorithm for cyber-attacks samples

    Science.gov (United States)

    Li, Yihong; Liu, Fangzheng; Du, Zhenyu

    2018-05-01

    By studying the defense scheme of Network attacks, this paper propose an effective traffic features selection algorithm based on k-means++ clustering to deal with the problem of high dimensionality of traffic features which extracted from cyber-attacks samples. Firstly, this algorithm divide the original feature set into attack traffic feature set and background traffic feature set by the clustering. Then, we calculates the variation of clustering performance after removing a certain feature. Finally, evaluating the degree of distinctiveness of the feature vector according to the result. Among them, the effective feature vector is whose degree of distinctiveness exceeds the set threshold. The purpose of this paper is to select out the effective features from the extracted original feature set. In this way, it can reduce the dimensionality of the features so as to reduce the space-time overhead of subsequent detection. The experimental results show that the proposed algorithm is feasible and it has some advantages over other selection algorithms.

  19. Random selection of items. Selection of n1 samples among N items composing a stratum

    International Nuclear Information System (INIS)

    Jaech, J.L.; Lemaire, R.J.

    1987-02-01

    STR-224 provides generalized procedures to determine required sample sizes, for instance in the course of a Physical Inventory Verification at Bulk Handling Facilities. The present report describes procedures to generate random numbers and select groups of items to be verified in a given stratum through each of the measurement methods involved in the verification. (author). 3 refs

  20. 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)

  1. [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.

  2. THE SDSS-IV EXTENDED BARYON OSCILLATION SPECTROSCOPIC SURVEY: LUMINOUS RED GALAXY TARGET SELECTION

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Abhishek; Licquia, Timothy C.; Newman, Jeffrey A.; Rao, Sandhya M. [PITT PACC, Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Ross, Ashley J. [Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Dawson, Kyle S.; Bautista, Julian E.; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Kneib, Jean-Paul [Laboratoire d’Astrophysique, Ecole Polytechnique Fédérale de Lausanne Observatoire de Sauverny, 1290 Versoix (Switzerland); Percival, Will J. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Comparat, Johan [Instituto de Física Teórica, (UAM/CSIC), Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Tinker, Jeremy L. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Schlegel, David J. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Tojeiro, Rita [School of Physics and Astronomy, St Andrews, KY16 9SS (United Kingdom); Ho, Shirley; Lang, Dustin [Bruce and Astrid McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); McBride, Cameron K. [Harvard-Smithsonian Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Zhu, Guangtun Ben, E-mail: abp15@pitt.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); and others

    2016-06-01

    We describe the algorithm used to select the luminous red galaxy (LRG) sample for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV) using photometric data from both the SDSS and the Wide-field Infrared Survey Explorer . LRG targets are required to meet a set of color selection criteria and have z -band and i -band MODEL magnitudes z < 19.95 and 19.9 < i < 21.8, respectively. Our algorithm selects roughly 50 LRG targets per square degree, the great majority of which lie in the redshift range 0.6 < z < 1.0 (median redshift 0.71). We demonstrate that our methods are highly effective at eliminating stellar contamination and lower-redshift galaxies. We perform a number of tests using spectroscopic data from SDSS-III/BOSS ancillary programs to determine the redshift reliability of our target selection and its ability to meet the science requirements of eBOSS. The SDSS spectra are of high enough signal-to-noise ratio that at least ∼89% of the target sample yields secure redshift measurements. We also present tests of the uniformity and homogeneity of the sample, demonstrating that it should be clean enough for studies of the large-scale structure of the universe at higher redshifts than SDSS-III/BOSS LRGs reached.

  3. THE zCOSMOS-SINFONI PROJECT. I. SAMPLE SELECTION AND NATURAL-SEEING OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, C.; Renzini, A. [INAF-OAPD, Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy); Foerster Schreiber, N. M.; Hicks, E. K. S.; Genzel, R.; Tacconi, L.; Davies, R. [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Cresci, G. [Osservatorio Astrofisico di Arcetri (OAF), INAF-Firenze, Largo E. Fermi 5, I-50125 Firenze (Italy); Peng, Y.; Lilly, S.; Carollo, M.; Oesch, P. [Institute of Astronomy, Department of Physics, Eidgenossische Technische Hochschule, ETH Zurich CH-8093 (Switzerland); Vergani, D.; Pozzetti, L.; Zamorani, G. [INAF-Bologna, Via Ranzani, I-40127 Bologna (Italy); Daddi, E. [CEA-Saclay, DSM/DAPNIA/Service d' Astrophysique, F-91191 Gif-Sur Yvette Cedex (France); Maraston, C. [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, PO1 3HE Portsmouth (United Kingdom); McCracken, H. J. [IAP, 98bis bd Arago, F-75014 Paris (France); Bouche, N. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Shapiro, K. [Aerospace Research Laboratories, Northrop Grumman Aerospace Systems, Redondo Beach, CA 90278 (United States); and others

    2011-12-10

    The zCOSMOS-SINFONI project is aimed at studying the physical and kinematical properties of a sample of massive z {approx} 1.4-2.5 star-forming galaxies, through SINFONI near-infrared integral field spectroscopy (IFS), combined with the multiwavelength information from the zCOSMOS (COSMOS) survey. The project is based on one hour of natural-seeing observations per target, and adaptive optics (AO) follow-up for a major part of the sample, which includes 30 galaxies selected from the zCOSMOS/VIMOS spectroscopic survey. This first paper presents the sample selection, and the global physical characterization of the target galaxies from multicolor photometry, i.e., star formation rate (SFR), stellar mass, age, etc. The H{alpha} integrated properties, such as, flux, velocity dispersion, and size, are derived from the natural-seeing observations, while the follow-up AO observations will be presented in the next paper of this series. Our sample appears to be well representative of star-forming galaxies at z {approx} 2, covering a wide range in mass and SFR. The H{alpha} integrated properties of the 25 H{alpha} detected galaxies are similar to those of other IFS samples at the same redshifts. Good agreement is found among the SFRs derived from H{alpha} luminosity and other diagnostic methods, provided the extinction affecting the H{alpha} luminosity is about twice that affecting the continuum. A preliminary kinematic analysis, based on the maximum observed velocity difference across the source and on the integrated velocity dispersion, indicates that the sample splits nearly 50-50 into rotation-dominated and velocity-dispersion-dominated galaxies, in good agreement with previous surveys.

  4. Simulating future uncertainty to guide the selection of survey designs for long-term monitoring

    Science.gov (United States)

    Garman, Steven L.; Schweiger, E. William; Manier, Daniel J.; Gitzen, Robert A.; Millspaugh, Joshua J.; Cooper, Andrew B.; Licht, Daniel S.

    2012-01-01

    A goal of environmental monitoring is to provide sound information on the status and trends of natural resources (Messer et al. 1991, Theobald et al. 2007, Fancy et al. 2009). When monitoring observations are acquired by measuring a subset of the population of interest, probability sampling as part of a well-constructed survey design provides the most reliable and legally defensible approach to achieve this goal (Cochran 1977, Olsen et al. 1999, Schreuder et al. 2004; see Chapters 2, 5, 6, 7). Previous works have described the fundamentals of sample surveys (e.g. Hansen et al. 1953, Kish 1965). Interest in survey designs and monitoring over the past 15 years has led to extensive evaluations and new developments of sample selection methods (Stevens and Olsen 2004), of strategies for allocating sample units in space and time (Urquhart et al. 1993, Overton and Stehman 1996, Urquhart and Kincaid 1999), and of estimation (Lesser and Overton 1994, Overton and Stehman 1995) and variance properties (Larsen et al. 1995, Stevens and Olsen 2003) of survey designs. Carefully planned, “scientific” (Chapter 5) survey designs have become a standard in contemporary monitoring of natural resources. Based on our experience with the long-term monitoring program of the US National Park Service (NPS; Fancy et al. 2009; Chapters 16, 22), operational survey designs tend to be selected using the following procedures. For a monitoring indicator (i.e. variable or response), a minimum detectable trend requirement is specified, based on the minimum level of change that would result in meaningful change (e.g. degradation). A probability of detecting this trend (statistical power) and an acceptable level of uncertainty (Type I error; see Chapter 2) within a specified time frame (e.g. 10 years) are specified to ensure timely detection. Explicit statements of the minimum detectable trend, the time frame for detecting the minimum trend, power, and acceptable probability of Type I error (

  5. 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.

  6. Target Selection for the SDSS-IV APOGEE-2 Survey

    Energy Technology Data Exchange (ETDEWEB)

    Zasowski, G. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Cohen, R. E.; Carlberg, J. K.; Fleming, Scott W. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Chojnowski, S. D.; Holtzman, J. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88001 (United States); Santana, F. [Departamento de Astronomía, Universidad de Chile, Santiago (Chile); Oelkers, R. J.; Bird, J. C. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Andrews, B. [PITT PACC, Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Beaton, R. L. [The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Bender, C.; Cunha, K. [Steward Observatory, The University of Arizona, Tucson, AZ 85719 (United States); Bovy, J. [Department of Astronomy and Astrophysics and Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Covey, K. [Department of Physics and Astronomy, Western Washington University, Bellingham, WA 98225 (United States); Dell’Agli, F.; García-Hernández, D. A. [Departamento de Astrofísica, Universidad de La Laguna, and Instituto de Astrofísica de Canarias, La Laguna, Tenerife (Spain); Frinchaboy, P. M. [Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129 (United States); Harding, P. [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Johnson, J. A., E-mail: gail.zasowski@gmail.com [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); and others

    2017-11-01

    APOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing ∼3 × 10{sup 5} stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV (SDSS-IV). APOGEE-2 is expanding on APOGEE’s goals of addressing critical questions of stellar astrophysics, stellar populations, and Galactic chemodynamical evolution using (1) an enhanced set of target types and (2) a second spectrograph at Las Campanas Observatory in Chile. APOGEE-2 is targeting red giant branch and red clump stars, RR Lyrae, low-mass dwarf stars, young stellar objects, and numerous other Milky Way and Local Group sources across the entire sky from both hemispheres. In this paper, we describe the APOGEE-2 observational design, target selection catalogs and algorithms, and the targeting-related documentation included in the SDSS data releases.

  7. Target Selection for the SDSS-IV APOGEE-2 Survey

    International Nuclear Information System (INIS)

    Zasowski, G.; Cohen, R. E.; Carlberg, J. K.; Fleming, Scott W.; Chojnowski, S. D.; Holtzman, J.; Santana, F.; Oelkers, R. J.; Bird, J. C.; Andrews, B.; Beaton, R. L.; Bender, C.; Cunha, K.; Bovy, J.; Covey, K.; Dell’Agli, F.; García-Hernández, D. A.; Frinchaboy, P. M.; Harding, P.; Johnson, J. A.

    2017-01-01

    APOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing ∼3 × 10 5 stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV (SDSS-IV). APOGEE-2 is expanding on APOGEE’s goals of addressing critical questions of stellar astrophysics, stellar populations, and Galactic chemodynamical evolution using (1) an enhanced set of target types and (2) a second spectrograph at Las Campanas Observatory in Chile. APOGEE-2 is targeting red giant branch and red clump stars, RR Lyrae, low-mass dwarf stars, young stellar objects, and numerous other Milky Way and Local Group sources across the entire sky from both hemispheres. In this paper, we describe the APOGEE-2 observational design, target selection catalogs and algorithms, and the targeting-related documentation included in the SDSS data releases.

  8. Evaluation of pump pulsation in respirable size-selective sampling: part II. Changes in sampling efficiency.

    Science.gov (United States)

    Lee, Eun Gyung; Lee, Taekhee; Kim, Seung Won; Lee, Larry; Flemmer, Michael M; Harper, Martin

    2014-01-01

    This second, and concluding, part of this study evaluated changes in sampling efficiency of respirable size-selective samplers due to air pulsations generated by the selected personal sampling pumps characterized in Part I (Lee E, Lee L, Möhlmann C et al. Evaluation of pump pulsation in respirable size-selective sampling: Part I. Pulsation measurements. Ann Occup Hyg 2013). Nine particle sizes of monodisperse ammonium fluorescein (from 1 to 9 μm mass median aerodynamic diameter) were generated individually by a vibrating orifice aerosol generator from dilute solutions of fluorescein in aqueous ammonia and then injected into an environmental chamber. To collect these particles, 10-mm nylon cyclones, also known as Dorr-Oliver (DO) cyclones, were used with five medium volumetric flow rate pumps. Those were the Apex IS, HFS513, GilAir5, Elite5, and Basic5 pumps, which were found in Part I to generate pulsations of 5% (the lowest), 25%, 30%, 56%, and 70% (the highest), respectively. GK2.69 cyclones were used with the Legacy [pump pulsation (PP) = 15%] and Elite12 (PP = 41%) pumps for collection at high flows. The DO cyclone was also used to evaluate changes in sampling efficiency due to pulse shape. The HFS513 pump, which generates a more complex pulse shape, was compared to a single sine wave fluctuation generated by a piston. The luminescent intensity of the fluorescein extracted from each sample was measured with a luminescence spectrometer. Sampling efficiencies were obtained by dividing the intensity of the fluorescein extracted from the filter placed in a cyclone with the intensity obtained from the filter used with a sharp-edged reference sampler. Then, sampling efficiency curves were generated using a sigmoid function with three parameters and each sampling efficiency curve was compared to that of the reference cyclone by constructing bias maps. In general, no change in sampling efficiency (bias under ±10%) was observed until pulsations exceeded 25% for the

  9. Adult health study reference papers. Selection of the sample. Characteristics of the sample

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, G W; Fujisawa, Hideo; Yamasaki, Mitsuru

    1960-12-14

    The characteristics and selection of the clinical sample have been described in some detail to provide information on the comparability of the exposure groups with respect to factors excluded from the matching criteria and to provide basic descriptive information potentially relevant to individual studies that may be done within the framework of the Adult Health Study. The characteristics under review here are age, sex, many different aspects of residence, marital status, occupation and industry, details of location and shielding ATB, acute radiation signs and symptoms, and prior ABCC medical or pathology examinations. 5 references, 57 tables.

  10. Reproductive performance in a select sample of dairy herds.

    Science.gov (United States)

    Ferguson, James D; Skidmore, Andrew

    2013-02-01

    Sixteen herds were selected from a pool of 64 herds nominated by consultants for participation in a national survey to demonstrate excellence in reproductive performance. For inclusion in the survey, herds had to have comprehensive records in a farm computer database or participate in a Dairy Herd Improvement Association record system and have superior reproductive performance as judged by the herd advisor. Herd managers were asked to fill out a questionnaire to describe their reproductive management practices and provide herd records for data analysis. Reproductive analysis was based on individual cow records for active and cull dairy cows that calved during the calendar year 2010. Breeding records by cow were used to calculate indices for insemination rate (IR), conception rate (CR), pregnancy rate (PR), and culling. Herds ranged in size from 262 to 6,126 lactating and dry cows, with a mean of 1,654 [standard deviation (SD) 1,494] cows. Mean days to first insemination (DFS) was 71.2d (SD 4.7d), and IR for first insemination was 86.9%. Mean days between inseminations were 33.4d (SD 3.1d), and 15.4% of insemination intervals were greater than 48 d (range: 7.2 to 21.5%). First-service conception rate was 44.4% (SD 4.8%) across all herds and ranged from 37.5 to 51.8%. Mean PR was 32.0% (SD 3.9%) with a range of 26.5 to 39.4%. Lactation cull rate was 32.2% (SD 12.4%) with a range from 13.6 to 58.1%. Compared with mean data and SD for herds in the Raleigh Dairy Herd Improvement Association system, mean indices for these herds ranked them in the 99 th percentile for IR (using heat detection rate as comparison), 99 th percentile for PR, the bottom 18.6 percentile for DFS, and around the 50th percentile for CR. This suggests that excellent herd reproductive performance was associated with reproductive management that resulted in high insemination rates combined with average CR. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights

  11. 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...

  12. 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

  13. ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; Berian James, J. [Astronomy Department, University of California, Berkeley, CA 94720-7450 (United States); Brink, Henrik [Dark Cosmology Centre, Juliane Maries Vej 30, 2100 Copenhagen O (Denmark); Long, James P.; Rice, John, E-mail: jwrichar@stat.berkeley.edu [Statistics Department, University of California, Berkeley, CA 94720-7450 (United States)

    2012-01-10

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL-where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up-is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  14. ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION

    International Nuclear Information System (INIS)

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; Berian James, J.; Brink, Henrik; Long, James P.; Rice, John

    2012-01-01

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL—where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up—is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  15. Active Learning to Overcome Sample Selection Bias: Application to Photometric Variable Star Classification

    Science.gov (United States)

    Richards, Joseph W.; Starr, Dan L.; Brink, Henrik; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; James, J. Berian; Long, James P.; Rice, John

    2012-01-01

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL—where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up—is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  16. The Munich Near-Infrared Cluster Survey - IX. Galaxy evolution to z ~ 2 from optically selected catalogues†‡

    Science.gov (United States)

    Feulner, Georg; Goranova, Yuliana; Hopp, Ulrich; Gabasch, Armin; Bender, Ralf; Botzler, Christine S.; Drory, Niv

    2007-06-01

    We present B-, R- and I-band-selected galaxy catalogues based on the Munich Near-Infrared Cluster Survey (MUNICS) which, together with the previously used K-selected sample, serve as an important probe of galaxy evolution in the redshift range 0 Karl-Schwarzschild Strasse 2, D-85748, Garching bei München, Germany.

  17. Selection Component Analysis of Natural Polymorphisms using Population Samples Including Mother-Offspring Combinations, II

    DEFF Research Database (Denmark)

    Jarmer, Hanne Østergaard; Christiansen, Freddy Bugge

    1981-01-01

    Population samples including mother-offspring combinations provide information on the selection components: zygotic selection, sexual selection, gametic seletion and fecundity selection, on the mating pattern, and on the deviation from linkage equilibrium among the loci studied. The theory...

  18. Progressive sample processing of band selection for hyperspectral imagery

    Science.gov (United States)

    Liu, Keng-Hao; Chien, Hung-Chang; Chen, Shih-Yu

    2017-10-01

    Band selection (BS) is one of the most important topics in hyperspectral image (HSI) processing. The objective of BS is to find a set of representative bands that can represent the whole image with lower inter-band redundancy. Many types of BS algorithms were proposed in the past. However, most of them can be carried on in an off-line manner. It means that they can only be implemented on the pre-collected data. Those off-line based methods are sometime useless for those applications that are timeliness, particular in disaster prevention and target detection. To tackle this issue, a new concept, called progressive sample processing (PSP), was proposed recently. The PSP is an "on-line" framework where the specific type of algorithm can process the currently collected data during the data transmission under band-interleavedby-sample/pixel (BIS/BIP) protocol. This paper proposes an online BS method that integrates a sparse-based BS into PSP framework, called PSP-BS. In PSP-BS, the BS can be carried out by updating BS result recursively pixel by pixel in the same way that a Kalman filter does for updating data information in a recursive fashion. The sparse regression is solved by orthogonal matching pursuit (OMP) algorithm, and the recursive equations of PSP-BS are derived by using matrix decomposition. The experiments conducted on a real hyperspectral image show that the PSP-BS can progressively output the BS status with very low computing time. The convergence of BS results during the transmission can be quickly achieved by using a rearranged pixel transmission sequence. This significant advantage allows BS to be implemented in a real time manner when the HSI data is transmitted pixel by pixel.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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.…

  5. 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.

  6. A survey of selected Internet pharmacies in the United States.

    Science.gov (United States)

    Peterson, A M

    2001-01-01

    To determine whether differences in the provision of pharmacy services exist among different types of Internet pharmacies. Survey of selected pharmacies with a presence on the Internet. Data were abstracted onto a data collection form for further analysis. Data collection was limited to 3 weeks. U.S.-based Internet pharmacies that allow patients to purchase prescription medications online. Pharmacies were identified using a metasearch engine with the search terms "Internet pharmacy" and "Internet pharmacist." Survey. Comparisons of availability of 10 commonly used products representing a variety of product categories, prescription verification methods, and privacy issues; and determinations of site navigability, drug information and provider access, and payment methods. Sites were categorized as "chain pharmacy extensions," "mail order pharmacies," "independent pharmacy extensions," and "online pharmacies." Thirty-three sites were reviewed. There was significant variation among the four types of pharmacies selling prescriptions over the Internet. Most pharmacies provided all of the drugs in the survey. Patients were required to provide their own prescription at 88% of the sites, and 75% of sites used mail or fax to verify prescription integrity. More than 50% of sites had privacy policies posted, and 64% used cookies. Chain pharmacy extensions required completion of an average of 10.2 pages to order drugs versus 2.4 to 4 pages for all other site types. Drug information was written at an eighth-grade reading level at 36% of the sites. More than two-thirds of the sites provided a toll-free telephone for a health care professional. Nearly 80% of the sites accepted health insurance, and 95% accepted credit cards; however, only 40% used a secure transmission mechanism for patient or payment information. Internet pharmacies provide varying levels of service. Policies regarding the use of the Internet for obtaining medications should focus on improving the privacy of

  7. Colored Sticky Traps to Selectively Survey Thrips in Cowpea Ecosystem.

    Science.gov (United States)

    Tang, L D; Zhao, H Y; Fu, B L; Han, Y; Liu, K; Wu, J H

    2016-02-01

    The bean flower thrips, Megalurothrips usitatus (Bagrall) (Thysanoptera: Thripidae), is an important pest of legume crops in South China. Yellow, blue, or white sticky traps are currently recommended for monitoring and controlling thrips, but it is not known whether one is more efficient than the other or if selectivity could be optimized by trap color. We investigated the response of thrips and beneficial insects to different-colored sticky traps on cowpea, Vigna unguiculata. More thrips were caught on blue, light blue, white, and purple traps than on yellow, green, pink, gray, red, or black traps. There was a weak correlation on the number of thrips caught on yellow traps and survey from flowers (r = 0.139), whereas a strong correlation was found for blue traps and thrips' survey on flowers (r = 0.929). On commercially available sticky traps (Jiaduo®), two and five times more thrips were caught on blue traps than on white and yellow traps, respectively. Otherwise, capture of beneficial insects was 1.7 times higher on yellow than on blue traps. The major natural enemies were the predatory ladybird beetles (63%) and pirate bugs Orius spp. (29%), followed by a number of less representative predators and parasitoids (8%). We conclude the blue sticky trap was the best to monitor thrips on cowpea in South China.

  8. 40 CFR 86.607-84 - Sample selection.

    Science.gov (United States)

    2010-07-01

    ... Auditing of New Light-Duty Vehicles, Light-Duty Trucks, and Heavy-Duty Vehicles § 86.607-84 Sample..., once a manufacturer ships any vehicle from the test sample, it relinquishes the prerogative to conduct...

  9. SPIDERS: selection of spectroscopic targets using AGN candidates detected in all-sky X-ray surveys

    Science.gov (United States)

    Dwelly, T.; Salvato, M.; Merloni, A.; Brusa, M.; Buchner, J.; Anderson, S. F.; Boller, Th.; Brandt, W. N.; Budavári, T.; Clerc, N.; Coffey, D.; Del Moro, A.; Georgakakis, A.; Green, P. J.; Jin, C.; Menzel, M.-L.; Myers, A. D.; Nandra, K.; Nichol, R. C.; Ridl, J.; Schwope, A. D.; Simm, T.

    2017-07-01

    SPIDERS (SPectroscopic IDentification of eROSITA Sources) is a Sloan Digital Sky Survey IV (SDSS-IV) survey running in parallel to the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) cosmology project. SPIDERS will obtain optical spectroscopy for large numbers of X-ray-selected active galactic nuclei (AGN) and galaxy cluster members detected in wide-area eROSITA, XMM-Newton and ROSAT surveys. We describe the methods used to choose spectroscopic targets for two sub-programmes of SPIDERS X-ray selected AGN candidates detected in the ROSAT All Sky and the XMM-Newton Slew surveys. We have exploited a Bayesian cross-matching algorithm, guided by priors based on mid-IR colour-magnitude information from the Wide-field Infrared Survey Explorer survey, to select the most probable optical counterpart to each X-ray detection. We empirically demonstrate the high fidelity of our counterpart selection method using a reference sample of bright well-localized X-ray sources collated from XMM-Newton, Chandra and Swift-XRT serendipitous catalogues, and also by examining blank-sky locations. We describe the down-selection steps which resulted in the final set of SPIDERS-AGN targets put forward for spectroscopy within the eBOSS/TDSS/SPIDERS survey, and present catalogues of these targets. We also present catalogues of ˜12 000 ROSAT and ˜1500 XMM-Newton Slew survey sources that have existing optical spectroscopy from SDSS-DR12, including the results of our visual inspections. On completion of the SPIDERS programme, we expect to have collected homogeneous spectroscopic redshift information over a footprint of ˜7500 deg2 for >85 per cent of the ROSAT and XMM-Newton Slew survey sources having optical counterparts in the magnitude range 17 < r < 22.5, producing a large and highly complete sample of bright X-ray-selected AGN suitable for statistical studies of AGN evolution and clustering.

  10. 40 CFR 91.506 - Engine sample selection.

    Science.gov (United States)

    2010-07-01

    ... paragraph (b)(2) of this section. It defines one-tail, 95 percent confidence intervals. σ=actual test sample... individual engine x=mean of emission test results of the actual sample FEL=Family Emission Limit n=The actual... carry-over engine families: After one engine is tested, the manufacturer will combine the test with the...

  11. 40 CFR 761.353 - Second level of sample selection.

    Science.gov (United States)

    2010-07-01

    .... At the chemical extraction and analysis laboratory, pour the 19-liter subsample onto a plastic sheet..., AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

  12. The selection function of the LAMOST Spectroscopic Survey of the Galactic Anti-centre

    Science.gov (United States)

    Chen, B.-Q.; Liu, X.-W.; Yuan, H.-B.; Xiang, M.-S.; Huang, Y.; Wang, C.; Zhang, H.-W.; Tian, Z.-J.

    2018-05-01

    We present a detailed analysis of the selection function of the LAMOST Spectroscopic Survey of the Galactic Anti-centre (LSS-GAC). LSS-GAC was designed to obtain low-resolution optical spectra for a sample of more than 3 million stars in the Galactic anti-centre. The second release of value-added catalogues of the LSS-GAC (LSS-GAC DR2) contains stellar parameters, including radial velocity, atmospheric parameters, elemental abundances, and absolute magnitudes deduced from 1.8 million spectra of 1.4 million unique stars targeted by the LSS-GAC between 2011 and 2014. For many studies using this data base, such as those investigating the chemodynamical structure of the Milky Way, a detailed understanding of the selection function of the survey is indispensable. In this paper, we describe how the selection function of the LSS-GAC can be evaluated to sufficient detail and provide selection function corrections for all spectroscopic measurements with reliable parameters released in LSS-GAC DR2. The results, to be released as new entries in the LSS-GAC value-added catalogues, can be used to correct the selection effects of the catalogue for scientific studies of various purposes.

  13. Factors to Consider in Selecting an Organisational Improvement Initiative: Survey Results

    Directory of Open Access Journals (Sweden)

    Mohammad Musli

    2017-01-01

    Full Text Available Organisations should select the appropriate improvement initiative that will fit with the context of organisation and provide value to the organisation. This paper presents 18 factors to be considered when selecting an organisational improvement initiative. Organisational improvement initiatives are approaches, management systems, tools and/or techniques that can be used for managing and improving organisations, such as Lean, ISO9001, Six Sigma and Improvement Team. A survey was conducted to identify the level of importance of these 18 factors as criteria for selecting an improvement initiative. Purposive sampling was used for this survey involving practitioners, managers, engineers, executives, consultants and/or academicians, who have been involved in the selection and/or implementation of organisational improvement initiatives in Malaysia. Two factors were rated as ‘very high importance’, which involve: (1 The ability to gain top management commitment and support to introduce and implement the initiative successfully, and (2 The initiative is aligned to the vision, mission and/or purpose of the organisation. All these factors can be adopted by the organisations as decision criteria to assist in the selection of the most appropriate improvement initiative based on rational decision making.

  14. Selections from 2017: Hubble Survey Explores Distant Galaxies

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.CANDELS Multi-Wavelength Catalogs: Source Identification and Photometry in the CANDELS COSMOSSurvey FieldPublished January2017Main takeaway:A publication led byHooshang Nayyeri(UC Irvine and UC Riverside) early this year details acatalog of sources built using the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey(CANDELS), a survey carried out by cameras on board the Hubble Space Telescope. The catalogliststhe properties of 38,000 distant galaxies visiblewithin the COSMOS field, a two-square-degree equatorial field explored in depthto answer cosmological questions.Why its interesting:Illustration showing the three-dimensional map of the dark matter distribution in theCOSMOS field. [Adapted from NASA/ESA/R. Massey(California Institute of Technology)]The depth and resolution of the CANDELS observations areuseful for addressingseveral major science goals, including the following:Studying the most distant objects in the universe at the epoch of reionization in the cosmic dawn.Understanding galaxy formation and evolution during the peak epoch of star formation in the cosmic high noon.Studying star formation from deep ultravioletobservations and studying cosmology from supernova observations.Why CANDELS is a major endeavor:CANDELS isthe largest multi-cycle treasury program ever approved on the Hubble Space Telescope using over 900 orbits between 2010 and 2013 withtwo cameras on board the spacecraftto study galaxy formation and evolution throughout cosmic time. The CANDELS images are all publicly available, and the new catalogrepresents an enormous source of information about distant objectsin our universe.CitationH. Nayyeri et al 2017 ApJS 228 7. doi:10.3847/1538-4365/228/1/7

  15. 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.

  16. 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.

  17. 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.

  18. Enhanced Sampling and Analysis, Selection of Technology for Testing

    Energy Technology Data Exchange (ETDEWEB)

    Svoboda, John; Meikrantz, David

    2010-02-01

    The focus of this study includes the investigation of sampling technologies used in industry and their potential application to nuclear fuel processing. The goal is to identify innovative sampling methods using state of the art techniques that could evolve into the next generation sampling and analysis system for metallic elements. This report details the progress made in the first half of FY 2010 and includes a further consideration of the research focus and goals for this year. Our sampling options and focus for the next generation sampling method are presented along with the criteria used for choosing our path forward. We have decided to pursue the option of evaluating the feasibility of microcapillary based chips to remotely collect, transfer, track and supply microliters of sample solutions to analytical equipment in support of aqueous processes for used nuclear fuel cycles. Microchip vendors have been screened and a choice made for the development of a suitable microchip design followed by production of samples for evaluation by ANL, LANL, and INL on an independent basis.

  19. 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...

  20. 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...

  1. 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…

  2. Sample selection and taste correlation in discrete choice transport modelling

    DEFF Research Database (Denmark)

    Mabit, Stefan Lindhard

    2008-01-01

    explain counterintuitive results in value of travel time estimation. However, the results also point at the difficulty of finding suitable instruments for the selection mechanism. Taste heterogeneity is another important aspect of discrete choice modelling. Mixed logit models are designed to capture...... the question for a broader class of models. It is shown that the original result may be somewhat generalised. Another question investigated is whether mode choice operates as a self-selection mechanism in the estimation of the value of travel time. The results show that self-selection can at least partly...... of taste correlation in willingness-to-pay estimation are presented. The first contribution addresses how to incorporate taste correlation in the estimation of the value of travel time for public transport. Given a limited dataset the approach taken is to use theory on the value of travel time as guidance...

  3. Experimental breakdown of selected anodized aluminum samples in dilute plasmas

    Science.gov (United States)

    Grier, Norman T.; Domitz, Stanley

    1992-01-01

    Anodized aluminum samples representative of Space Station Freedom structural material were tested for electrical breakdown under space plasma conditions. In space, this potential arises across the insulating anodized coating when the spacecraft structure is driven to a negative bias relative to the external plasma potential due to plasma-surface interaction phenomena. For anodized materials used in the tests, it was found that breakdown voltage varied from 100 to 2000 volts depending on the sample. The current in the arcs depended on the sample, the capacitor, and the voltage. The level of the arc currents varied from 60 to 1000 amperes. The plasma number density varied from 3 x 10 exp 6 to 10 exp 3 ions per cc. The time between arcs increased as the number density was lowered. Corona testing of anodized samples revealed that samples with higher corona inception voltage had higher arcing inception voltages. From this it is concluded that corona testing may provide a method of screening the samples.

  4. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    KAUST Repository

    Elsheikh, Ahmed H.; Wheeler, Mary Fanett; Hoteit, Ibrahim

    2014-01-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using

  5. The Quasar Fraction in Low-Frequency Selected Complete Samples and Implications for Unified Schemes

    Science.gov (United States)

    Willott, Chris J.; Rawlings, Steve; Blundell, Katherine M.; Lacy, Mark

    2000-01-01

    Low-frequency radio surveys are ideal for selecting orientation-independent samples of extragalactic sources because the sample members are selected by virtue of their isotropic steep-spectrum extended emission. We use the new 7C Redshift Survey along with the brighter 3CRR and 6C samples to investigate the fraction of objects with observed broad emission lines - the 'quasar fraction' - as a function of redshift and of radio and narrow emission line luminosity. We find that the quasar fraction is more strongly dependent upon luminosity (both narrow line and radio) than it is on redshift. Above a narrow [OII] emission line luminosity of log(base 10) (L(sub [OII])/W) approximately > 35 [or radio luminosity log(base 10) (L(sub 151)/ W/Hz.sr) approximately > 26.5], the quasar fraction is virtually independent of redshift and luminosity; this is consistent with a simple unified scheme with an obscuring torus with a half-opening angle theta(sub trans) approximately equal 53 deg. For objects with less luminous narrow lines, the quasar fraction is lower. We show that this is not due to the difficulty of detecting lower-luminosity broad emission lines in a less luminous, but otherwise similar, quasar population. We discuss evidence which supports at least two probable physical causes for the drop in quasar fraction at low luminosity: (i) a gradual decrease in theta(sub trans) and/or a gradual increase in the fraction of lightly-reddened (0 approximately quasar luminosity; and (ii) the emergence of a distinct second population of low luminosity radio sources which, like M8T, lack a well-fed quasar nucleus and may well lack a thick obscuring torus.

  6. A large sample of Kohonen-selected SDSS quasars with weak emission lines: selection effects and statistical properties

    Science.gov (United States)

    Meusinger, H.; Balafkan, N.

    2014-08-01

    Aims: A tiny fraction of the quasar population shows remarkably weak emission lines. Several hypotheses have been developed, but the weak line quasar (WLQ) phenomenon still remains puzzling. The aim of this study was to create a sizeable sample of WLQs and WLQ-like objects and to evaluate various properties of this sample. Methods: We performed a search for WLQs in the spectroscopic data from the Sloan Digital Sky Survey Data Release 7 based on Kohonen self-organising maps for nearly 105 quasar spectra. The final sample consists of 365 quasars in the redshift range z = 0.6 - 4.2 (z¯ = 1.50 ± 0.45) and includes in particular a subsample of 46 WLQs with equivalent widths WMg iiattention was paid to selection effects. Results: The WLQs have, on average, significantly higher luminosities, Eddington ratios, and accretion rates. About half of the excess comes from a selection bias, but an intrinsic excess remains probably caused primarily by higher accretion rates. The spectral energy distribution shows a bluer continuum at rest-frame wavelengths ≳1500 Å. The variability in the optical and UV is relatively low, even taking the variability-luminosity anti-correlation into account. The percentage of radio detected quasars and of core-dominant radio sources is significantly higher than for the control sample, whereas the mean radio-loudness is lower. Conclusions: The properties of our WLQ sample can be consistently understood assuming that it consists of a mix of quasars at the beginning of a stage of increased accretion activity and of beamed radio-quiet quasars. The higher luminosities and Eddington ratios in combination with a bluer spectral energy distribution can be explained by hotter continua, i.e. higher accretion rates. If quasar activity consists of subphases with different accretion rates, a change towards a higher rate is probably accompanied by an only slow development of the broad line region. The composite WLQ spectrum can be reasonably matched by the

  7. The Complete Local Volume Groups Sample - I. Sample selection and X-ray properties of the high-richness subsample

    Science.gov (United States)

    O'Sullivan, Ewan; Ponman, Trevor J.; Kolokythas, Konstantinos; Raychaudhury, Somak; Babul, Arif; Vrtilek, Jan M.; David, Laurence P.; Giacintucci, Simona; Gitti, Myriam; Haines, Chris P.

    2017-12-01

    We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data to investigate the relationship between member galaxies, their active nuclei and the hot intra-group medium (IGM). We describe sample selection, define a 26-group high-richness subsample of groups containing at least four optically bright (log LB ≥ 10.2 LB⊙) galaxies, and report the results of XMM-Newton and Chandra observations of these systems. We find that 14 of the 26 groups are X-ray bright, possessing a group-scale IGM extending at least 65 kpc and with luminosity >1041 erg s-1, while a further three groups host smaller galaxy-scale gas haloes. The X-ray bright groups have masses in the range M500 ≃ 0.5-5 × 1013 M⊙, based on system temperatures of 0.4-1.4 keV, and X-ray luminosities in the range 2-200 × 1041 erg s-1. We find that ∼53-65 per cent of the X-ray bright groups have cool cores, a somewhat lower fraction than found by previous archival surveys. Approximately 30 per cent of the X-ray bright groups show evidence of recent dynamical interactions (mergers or sloshing), and ∼35 per cent of their dominant early-type galaxies host active galactic nuclei with radio jets. We find no groups with unusually high central entropies, as predicted by some simulations, and confirm that CLoGS is in principle capable of detecting such systems. We identify three previously unrecognized groups, and find that they are either faint (LX, R500 < 1042 erg s-1) with no concentrated cool core, or highly disturbed. This leads us to suggest that ∼20 per cent of X-ray bright groups in the local universe may still be unidentified.

  8. Sampling dynamics: an alternative to payoff-monotone selection dynamics

    DEFF Research Database (Denmark)

    Berkemer, Rainer

    payoff-monotone nor payoff-positive which has interesting consequences. This can be demonstrated by application to the travelers dilemma, a deliberately constructed social dilemma. The game has just one symmetric Nash equilibrium which is Pareto inefficient. Especially when the travelers have many......'' of the standard game theory result. Both, analytical tools and agent based simulation are used to investigate the dynamic stability of sampling equilibria in a generalized travelers dilemma. Two parameters are of interest: the number of strategy options (m) available to each traveler and an experience parameter...... (k), which indicates the number of samples an agent would evaluate before fixing his decision. The special case (k=1) can be treated analytically. The stationary points of the dynamics must be sampling equilibria and one can calculate that for m>3 there will be an interior solution in addition...

  9. Sampling Efficiency and Performance of Selected Thoracic Aerosol Samplers.

    Science.gov (United States)

    Görner, Peter; Simon, Xavier; Boivin, Alexis; Bau, Sébastien

    2017-08-01

    Measurement of worker exposure to a thoracic health-related aerosol fraction is necessary in a number of occupational situations. This is the case of workplaces with atmospheres polluted by fibrous particles, such as cotton dust or asbestos, and by particles inducing irritation or bronchoconstriction such as acid mists or flour dust. Three personal and two static thoracic aerosol samplers were tested under laboratory conditions. Sampling efficiency with respect to particle aerodynamic diameter was measured in a horizontal low wind tunnel and in a vertical calm air chamber. Sampling performance was evaluated against conventional thoracic penetration. Three of the tested samplers performed well, when sampling the thoracic aerosol at nominal flow rate and two others performed well at optimized flow rate. The limit of flow rate optimization was found when using cyclone samplers. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  10. 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...

  11. REAL-TIME ANALYSIS AND SELECTION BIASES IN THE SUPERNOVA LEGACY SURVEY

    International Nuclear Information System (INIS)

    Perrett, K.; Conley, A.; Carlberg, R.; Balam, D.; Hook, I. M.; Sullivan, M.; Pritchet, C.; Astier, P.; Balland, C.; Guy, J.; Hardin, D.; Pain, R.; Regnault, N.; Basa, S.; Fouchez, D.; Howell, D. A.

    2010-01-01

    The Supernova Legacy Survey (SNLS) has produced a high-quality, homogeneous sample of Type Ia supernovae (SNe Ia) out to redshifts greater than z = 1. In its first four years of full operation (to 2007 June), the SNLS discovered more than 3000 transient candidates, 373 of which have been spectroscopically confirmed as SNe Ia. Use of these SNe Ia in precision cosmology critically depends on an analysis of the observational biases incurred in the SNLS survey due to the incomplete sampling of the underlying SN Ia population. This paper describes our real-time supernova detection and analysis procedures, and uses detailed Monte Carlo simulations to examine the effects of Malmquist bias and spectroscopic sampling. Such sampling effects are found to become apparent at z ∼ 0.6, with a significant shift in the average magnitude of the spectroscopically confirmed SN Ia sample toward brighter values for z ∼> 0.75. We describe our approach to correct for these selection biases in our three-year SNLS cosmological analysis (SNLS3) and present a breakdown of the systematic uncertainties involved.

  12. Survey for service selection approaches in dynamic environments

    CSIR Research Space (South Africa)

    Manqele, Lindelweyizizwe S

    2017-09-01

    Full Text Available The usage of the service selection approaches across different dynamic service provisioning environments has increased the challenges associated with an effective method that can be used to select a relevant service. The use of service selection...

  13. Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

    Science.gov (United States)

    Crampin, A C; Mwinuka, V; Malema, S S; Glynn, J R; Fine, P E

    2001-01-01

    Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density. We also present an audit of the selection process, and discuss the potential of this method in other settings.

  14. 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.

  15. Plasma metanephrine for assessing the selectivity of adrenal venous sampling

    NARCIS (Netherlands)

    Dekkers, T.; Deinum, J.; Schultze Kool, L.J.; Blondin, D.; Vonend, O.; Hermus, A.R.M.M.; Peitzsch, M.; Rump, L.C.; Antoch, G.; Sweep, F.C.; Bornstein, S.R.; Lenders, J.W.M.; Willenberg, H.S.; Eisenhofer, G.

    2013-01-01

    Adrenal vein sampling is used to establish the origins of excess production of adrenal hormones in primary aldosteronism. Correct catheter positioning is confirmed using adrenal vein measurements of cortisol, but this parameter is not always reliable. Plasma metanephrine represents an alternative

  16. Systematic sampling of discrete and continuous populations: sample selection and the choice of estimator

    Science.gov (United States)

    Harry T. Valentine; David L. R. Affleck; Timothy G. Gregoire

    2009-01-01

    Systematic sampling is easy, efficient, and widely used, though it is not generally recognized that a systematic sample may be drawn from the population of interest with or without restrictions on randomization. The restrictions or the lack of them determine which estimators are unbiased, when using the sampling design as the basis for inference. We describe the...

  17. 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...

  18. The Gender Wage Gap and Sample Selection via Risk Attitudes

    OpenAIRE

    Jung , Seeun

    2014-01-01

    This paper investigates a new way to estimate the gender wage gap with the introduction of individual risk attitudes using representative Korean data. We es- timate the wage gap with correction for the selection bias, which latter results in the overestimation of this wage gap. Female workers are more risk averse. They hence prefer working in the public sector, where wages are generally lower than in the private sector. It goes on to explain the reduced gender wage gap by develop- ing an appr...

  19. 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

  20. 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

  1. Risk Attitudes, Sample Selection and Attrition in a Longitudinal Field Experiment

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten Igel

    with respect to risk attitudes. Our design builds in explicit randomization on the incentives for participation. We show that there are significant sample selection effects on inferences about the extent of risk aversion, but that the effects of subsequent sample attrition are minimal. Ignoring sample...... selection leads to inferences that subjects in the population are more risk averse than they actually are. Correcting for sample selection and attrition affects utility curvature, but does not affect inferences about probability weighting. Properly accounting for sample selection and attrition effects leads...... to findings of temporal stability in overall risk aversion. However, that stability is around different levels of risk aversion than one might naively infer without the controls for sample selection and attrition we are able to implement. This evidence of “randomization bias” from sample selection...

  2. Radon prevention in new construction. Sample survey 2009

    International Nuclear Information System (INIS)

    Arvela, H.; Maekelaeinen, I.; Holmgren, O.; Reisbacka, H.

    2010-05-01

    The building code for radon prevention and the associated practical guidelines were revised in Finland in 2003 to 2004. Thereafter, preventive measures have become more common and prevention practices more effective. Consequently, indoor radon concentrations in new construction have been markedly reduced. In this study, the indoor radon concentration was measured in 1 500 new lowrise residential houses. The houses were randomly selected and represented 7 % of houses that received building permission in 2006. The average radon concentration of all houses measured, which were completed in 2006 to 2008, was 95 Bq/m 3 , the median being 58 Bq/m 3 . The average was 30 % lower than in houses completed in 2000 to 2005. The decrease was 50 % in provinces with the highest indoor radon concentration and 20 % elsewhere in the country. In houses with a slab-on-ground foundation that had both passive radon piping and sealing measures carried out using a strip of bitumen felt in the joint between the foundation wall and floor slab, the radon concentration was on average reduced by 55 % compared to houses with no preventive measures. Preventive measures were taken in 50 % of single family houses, and in provinces with the highest radon concentration in 90 % of houses. Active prevention in areas with high indoor radon concentrations has reduced the regional differences in the radon concentration. Slab on ground is the prevailing type of foundation and necessitates careful radon prevention measures throughout the country. The most serious defects were observed in prevention practices in houses with walls made of lightweight concrete blocks that were in contact with soil. The foundation types with the lowest radon concentrations were those with a crawl space and a monolithic slab. (orig.)

  3. Analysis of Selected Legacy 85Kr Samples

    Energy Technology Data Exchange (ETDEWEB)

    Jubin, Robert Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-02

    Legacy samples composed of 85Kr encapsulated in solid zeolite 5A material and five small metal tubes containing a mixture of the zeolite combined with a glass matrix resulting from hot isostatic pressing have been preserved. The samples were a result of krypton R&D encapsulation efforts in the late 1970s performed at the Idaho Chemical Processing Plant. These samples were shipped to Oak Ridge National Laboratory (ORNL) in mid-FY 2014. Upon receipt the outer shipping package was opened, and the inner package, removed and placed in a radiological hood. The individual capsules were double bagged as they were removed from the inner shipping pig and placed into individual glass sample bottles for further analysis. The five capsules were then x-ray imaged. Capsules 1 and 4 appear intact and to contain an amorphous mass within the capsules. Capsule 2 clearly shows the saw marks on the capsule and a quantity of loose pellet or bead-like material remaining in the capsule. Capsule 3 shows similar bead-like material within the intact capsule. Capsule 5 had been opened at an undetermined time in the past. The end of this capsule appears to have been cut off, and there are additional saw marks on the side of the capsule. X-ray tomography allowed the capsules to be viewed along the three axes. Of most interest was determining whether there was any residual material in the closed end of Capsule 5. The images confirmed the presence of residual material within this capsule. The material appears to be compacted but still retains some of the bead-like morphology. Based on the nondestructive analysis (NDA) results, a proposed path forward was formulated to advance this effort toward the original goals of understanding the effects of extended storage on the waste form and package. Based on the initial NDA and the fact that there are at least two breached samples, it was proposed that exploratory tests be conducted with the breached specimens before opening the three intact

  4. Learning spectrum's selection in OLAM network for analysis cement samples

    International Nuclear Information System (INIS)

    Huang Ning; Wang Peng; Tang Daiquan; Hu Renlan

    2010-01-01

    It uses OLAM artificial neural network to analyze the samples of cement raw material. Two kinds of spectrums are used for network learning: pure-element spectrum and mix-element spectrum. The output of pure-element method can be used to construct a simulate spectrum, which can be compared with the original spectrum and judge the shift of spectrum; the mix-element method can store more message and correct the matrix effect, but the multicollinearity among spectrums can cause some side effect to the results. (authors)

  5. Mineralogical, chemical, and petrographic analysis of selected rock samples

    International Nuclear Information System (INIS)

    Roy, D.M.

    1976-01-01

    I. The majority of rocks examined from the NTS were found to be siltstones, varying from coarse into the very fine siltstone range, and containing > 60% quartz, usually much higher. Samples of the UEIL series of cores, in contrast, had a large clay mineral fraction, as well as some carbonate present. A few were intermediate silty claystones or argillites. Microphotographs are included to illustrate the variations in texture observed, while most of the data obtained are summarized in tabular form. II. Seven Michigan Salina evaporite specimens were analyzed

  6. Selection of bone samples for 239Pu analyses in man

    International Nuclear Information System (INIS)

    Jee, W.S.S.; Wronski, T.J.; Smith, J.M.; Kimmel, D.B.; Miller, S.C.; Stover, B.J.

    1981-01-01

    Studies on the skeletal macrodistribution, microdistribution, and toxicity of 239 Pu and studies on bone turnover rates show that trabecular bone sites with high turnover rates have the greatest affinity for 239 Pu. In the adult beagle, these high-turnover, trabecular bone sites also show a higher occurrence of osteosarcomas. Correspondingly, high-turnover bone sites in the human would include the ilium (pelvis) and lumbar vertebrae (LVB), sites that are readily obtainable at autopsy. We recommend that the trabecular bone of the ilium and of the LVB be sampled to determine the skeletal radionuclide content of humans

  7. 40 CFR 205.160-2 - Test sample selection and preparation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test sample selection and preparation... sample selection and preparation. (a) Vehicles comprising the sample which are required to be tested... maintained in any manner unless such preparation, tests, modifications, adjustments or maintenance are part...

  8. Molecular and Serological Survey of Selected Viruses in Free-Ranging Wild Ruminants in Iran.

    Directory of Open Access Journals (Sweden)

    Farhid Hemmatzadeh

    Full Text Available A molecular and serological survey of selected viruses in free-ranging wild ruminants was conducted in 13 different districts in Iran. Samples were collected from 64 small wild ruminants belonging to four different species including 25 Mouflon (Ovis orientalis, 22 wild goat (Capra aegagrus, nine Indian gazelle (Gazella bennettii and eight Goitered gazelle (Gazella subgutturosa during the national survey for wildlife diseases in Iran. Serum samples were evaluated using serologic antibody tests for Peste de petits ruminants virus (PPRV, Pestiviruses [Border Disease virus (BVD and Bovine Viral Diarrhoea virus (BVDV], Bluetongue virus (BTV, Bovine herpesvirus type 1 (BHV-1, and Parainfluenza type 3 (PI3. Sera were also ELISA tested for Pestivirus antigen. Tissue samples including spleen, liver, lung, tonsils, mesenteric and mediastinal lymph nodes and white blood cells (WBCs were tested using polymerase chain reaction (PCR for PPRV, Foot and Mouth Disease virus (FMDV, Pestivirus, BTV, Ovine herpesvirus type 2 (OvHV-2 and BHV-1. Serologic tests were positive for antibodies against PPRV (17%, Pestiviruses (2% and BTV (2%. No antibodies were detected for BHV-1 or PI3, and no Pestivirus antigen was detected. PCR results were positive for PPRV (7.8%, FMDV (11%, BTV (3%, OvHV-2 (31% and BHV-1 (1.5%. None of the samples were positive for Pestiviruses.

  9. 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.

  10. Analysis of selected phytotoxins and mycotoxins in environmental samples.

    Science.gov (United States)

    Hoerger, Corinne C; Schenzel, Judith; Strobel, Bjarne W; Bucheli, Thomas D

    2009-11-01

    Natural toxins such as phytotoxins and mycotoxins have been studied in food and feed for decades, but little attention has yet been paid to their occurrence in the environment. Because of increasing awareness of the presence and potential relevance of micropollutants in the environment, phytotoxins and mycotoxins should be considered and investigated as part of the chemical cocktail in natural samples. Here, we compile chemical analytical methods to determine important phytotoxins (i.e. phenolic acids, quinones, benzoxazinones, terpenoids, glycoalkaloids, glucosinolates, isothiocyanates, phytosterols, flavonoids, coumestans, lignans, and chalcones) and mycotoxins (i.e. resorcyclic acid lactones, trichothecenes, fumonisins, and aflatoxins) in environmentally relevant matrices such as surface water, waste water-treatment plant influent and effluent, soil, sediment, manure, and sewage sludge. The main problems encountered in many of the reviewed methods were the frequent unavailability of suitable internal standards (especially isotope-labelled analogues) and often absent or fragmentary method optimization and validation.

  11. 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

  12. 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

  13. 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...

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. 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.

  19. 1996 hazardous waste management survey in selected Asian countries

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, D.; Christie, K.; Tao, Hong-lei [EnviroSearch International, Salt Lake City, UT (United States)

    1996-12-31

    This report documents the results of a 42-question survey submitted to countries in Asia concerning their hazardous waste management programs and other issues. The same survey questions were distributed in 1992. This report compares the 1992 and 1996 responses. The respondents were Australia, New Zealand, Malaysia, Philippines, Hong Kong, People`s Republic of China, Taiwan, Japan, Korea, Singapore, Thailand, and Indonesia. 7 figs.

  20. What Are Probability Surveys used by the National Aquatic Resource Surveys?

    Science.gov (United States)

    The National Aquatic Resource Surveys (NARS) use probability-survey designs to assess the condition of the nation’s waters. In probability surveys (also known as sample-surveys or statistical surveys), sampling sites are selected randomly.

  1. Measurement of radioactivity in the environment - Soil - Part 2: Guidance for the selection of the sampling strategy, sampling and pre-treatment of samples

    International Nuclear Information System (INIS)

    2007-01-01

    This part of ISO 18589 specifies the general requirements, based on ISO 11074 and ISO/IEC 17025, for all steps in the planning (desk study and area reconnaissance) of the sampling and the preparation of samples for testing. It includes the selection of the sampling strategy, the outline of the sampling plan, the presentation of general sampling methods and equipment, as well as the methodology of the pre-treatment of samples adapted to the measurements of the activity of radionuclides in soil. This part of ISO 18589 is addressed to the people responsible for determining the radioactivity present in soil for the purpose of radiation protection. It is applicable to soil from gardens, farmland, urban or industrial sites, as well as soil not affected by human activities. This part of ISO 18589 is applicable to all laboratories regardless of the number of personnel or the range of the testing performed. When a laboratory does not undertake one or more of the activities covered by this part of ISO 18589, such as planning, sampling or testing, the corresponding requirements do not apply. Information is provided on scope, normative references, terms and definitions and symbols, principle, sampling strategy, sampling plan, sampling process, pre-treatment of samples and recorded information. Five annexes inform about selection of the sampling strategy according to the objectives and the radiological characterization of the site and sampling areas, diagram of the evolution of the sample characteristics from the sampling site to the laboratory, example of sampling plan for a site divided in three sampling areas, example of a sampling record for a single/composite sample and example for a sample record for a soil profile with soil description. A bibliography is provided

  2. A Study of Quasar Selection in the Supernova Fields of the Dark Energy Survey

    International Nuclear Information System (INIS)

    Tie, S. S.; Martini, P.; Mudd, D.; Ostrovski, F.; Reed, S. L.

    2017-01-01

    In this paper, we present a study of quasar selection using the supernova fields of the Dark Energy Survey (DES). We used a quasar catalog from an overlapping portion of the SDSS Stripe 82 region to quantify the completeness and efficiency of selection methods involving color, probabilistic modeling, variability, and combinations of color/probabilistic modeling with variability. In all cases, we considered only objects that appear as point sources in the DES images. We examine color selection methods based on the Wide-field Infrared Survey Explorer (WISE) mid-IR W1-W2 color, a mixture of WISE and DES colors (g - i and i-W1), and a mixture of Vista Hemisphere Survey and DES colors (g - i and i - K). For probabilistic quasar selection, we used XDQSO, an algorithm that employs an empirical multi-wavelength flux model of quasars to assign quasar probabilities. Our variability selection uses the multi-band χ"2-probability that sources are constant in the DES Year 1 griz-band light curves. The completeness and efficiency are calculated relative to an underlying sample of point sources that are detected in the required selection bands and pass our data quality and photometric error cuts. We conduct our analyses at two magnitude limits, i 85% for both i-band magnitude limits and efficiencies of >80% to the bright limit and >60% to the faint limit; however, the giW1 and giW1+variability methods give the highest quasar surface densities. The XDQSOz method and combinations of W1W2/giW1/XDQSOz with variability are among the better selection methods when both high completeness and high efficiency are desired. We also present the OzDES Quasar Catalog of 1263 spectroscopically confirmed quasars from three years of OzDES observation in the 30 deg"2 of the DES supernova fields. Finally, the catalog includes quasars with redshifts up to z ~ 4 and brighter than i = 22 mag, although the catalog is not complete up to this magnitude limit.

  3. 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

  4. 40 CFR 205.171-2 - Test exhaust system sample selection and preparation.

    Science.gov (United States)

    2010-07-01

    ... Systems § 205.171-2 Test exhaust system sample selection and preparation. (a)(1) Exhaust systems... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Test exhaust system sample selection and preparation. 205.171-2 Section 205.171-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  5. Observed Characteristics and Teacher Quality: Impacts of Sample Selection on a Value Added Model

    Science.gov (United States)

    Winters, Marcus A.; Dixon, Bruce L.; Greene, Jay P.

    2012-01-01

    We measure the impact of observed teacher characteristics on student math and reading proficiency using a rich dataset from Florida. We expand upon prior work by accounting directly for nonrandom attrition of teachers from the classroom in a sample selection framework. We find evidence that sample selection is present in the estimation of the…

  6. 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.

  7. THE CLUSTERING CHARACTERISTICS OF H I-SELECTED GALAXIES FROM THE 40% ALFALFA SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ann M. [NASA Postdoctoral Program, NASA Langley Research Center, Hampton, VA 23618 (United States); Giovanelli, Riccardo; Haynes, Martha P. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Guzzo, Luigi, E-mail: ann.m.martin@nasa.gov, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu, E-mail: luigi.guzzo@brera.inaf.it [INAF Osservatorio Astronomico di Brera, Milan (Italy)

    2012-05-01

    The 40% Arecibo Legacy Fast ALFA survey catalog ({alpha}.40) of {approx}10,150 H I-selected galaxies is used to analyze the clustering properties of gas-rich galaxies. By employing the Landy-Szalay estimator and a full covariance analysis for the two-point galaxy-galaxy correlation function, we obtain the real-space correlation function and model it as a power law, {xi}(r) = (r/r{sub 0}){sup -{gamma}}, on scales <10 h{sup -1} Mpc. As the largest sample of blindly H I-selected galaxies to date, {alpha}.40 provides detailed understanding of the clustering of this population. We find {gamma} = 1.51 {+-} 0.09 and r{sub 0} = 3.3 + 0.3, -0.2 h{sup -1} Mpc, reinforcing the understanding that gas-rich galaxies represent the most weakly clustered galaxy population known; we also observe a departure from a pure power-law shape at intermediate scales, as predicted in {Lambda}CDM halo occupation distribution models. Furthermore, we measure the bias parameter for the {alpha}.40 galaxy sample and find that H I galaxies are severely antibiased on small scales, but only weakly antibiased on large scales. The robust measurement of the correlation function for gas-rich galaxies obtained via the {alpha}.40 sample constrains models of the distribution of H I in simulated galaxies, and will be employed to better understand the role of gas in environmentally dependent galaxy evolution.

  8. THE SDSS-III BARYON OSCILLATION SPECTROSCOPIC SURVEY: QUASAR TARGET SELECTION FOR DATA RELEASE NINE

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Nicholas P.; Kirkpatrick, Jessica A.; Carithers, William C.; Ho, Shirley [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Myers, Adam D. [Department of Astronomy, MC-221, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States); Sheldon, Erin S. [Brookhaven National Laboratory, Blgd 510, Upton, NY 11375 (United States); Yeche, Christophe; Aubourg, Eric [CEA, Centre de Saclay, IRFU, 91191 Gif-sur-Yvette (France); Strauss, Michael A.; Lee, Khee-Gan [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Bovy, Jo; Blanton, Michael R.; Hogg, David W. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Richards, Gordon T. [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Brandt, W. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Croft, Rupert A. C. [Bruce and Astrid McWilliams Center for Cosmology, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Da Silva, Robert [Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95064 (United States); Dawson, Kyle [Department of Physics and Astronomy, University of Utah, UT (United States); Eisenstein, Daniel J. [Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Hennawi, Joseph F., E-mail: npross@lbl.gov [Max-Planck-Institut fuer Astronomie, Konigstuhl 17, 69117 Heidelberg (Germany); and others

    2012-03-01

    The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a five-year spectroscopic survey of 10,000 deg{sup 2}, achieved first light in late 2009. One of the key goals of BOSS is to measure the signature of baryon acoustic oscillations (BAOs) in the distribution of Ly{alpha} absorption from the spectra of a sample of {approx}150,000 z > 2.2 quasars. Along with measuring the angular diameter distance at z Almost-Equal-To 2.5, BOSS will provide the first direct measurement of the expansion rate of the universe at z > 2. One of the biggest challenges in achieving this goal is an efficient target selection algorithm for quasars in the redshift range 2.2 < z < 3.5, where their colors tend to overlap those of the far more numerous stars. During the first year of the BOSS survey, quasar target selection (QTS) methods were developed and tested to meet the requirement of delivering at least 15 quasars deg{sup -2} in this redshift range, with a goal of 20 out of 40 targets deg{sup -2} allocated to the quasar survey. To achieve these surface densities, the magnitude limit of the quasar targets was set at g {<=} 22.0 or r {<=} 21.85. While detection of the BAO signature in the distribution of Ly{alpha} absorption in quasar spectra does not require a uniform target selection algorithm, many other astrophysical studies do. We have therefore defined a uniformly selected subsample of 20 targets deg{sup -2}, for which the selection efficiency is just over 50% ({approx}10 z > 2.20 quasars deg{sup -2}). This 'CORE' subsample will be fixed for Years Two through Five of the survey. For the remaining 20 targets deg{sup -2}, we will continue to develop improved selection techniques, including the use of additional data sets beyond the Sloan Digital Sky Survey (SDSS) imaging data. In this paper, we describe the evolution and implementation of the BOSS QTS algorithms during the first two years of BOSS operations (through 2011 July), in support of the science investigations

  9. 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

  10. 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 ...

  11. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    International Nuclear Information System (INIS)

    Elsheikh, Ahmed H.; Wheeler, Mary F.; Hoteit, Ibrahim

    2014-01-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems

  12. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    Energy Technology Data Exchange (ETDEWEB)

    Elsheikh, Ahmed H., E-mail: aelsheikh@ices.utexas.edu [Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, TX (United States); Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Wheeler, Mary F. [Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, TX (United States); Hoteit, Ibrahim [Department of Earth Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal (Saudi Arabia)

    2014-02-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems.

  13. [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.

  14. Pilot studies for the North American Soil Geochemical Landscapes Project - Site selection, sampling protocols, analytical methods, and quality control protocols

    Science.gov (United States)

    Smith, D.B.; Woodruff, L.G.; O'Leary, R. M.; Cannon, W.F.; Garrett, R.G.; Kilburn, J.E.; Goldhaber, M.B.

    2009-01-01

    In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada sampled and chemically analyzed soils along two transects across Canada and the USA in preparation for a planned soil geochemical survey of North America. This effort was a pilot study to test and refine sampling protocols, analytical methods, quality control protocols, and field logistics for the continental survey. A total of 220 sample sites were selected at approximately 40-km intervals along the two transects. The ideal sampling protocol at each site called for a sample from a depth of 0-5 cm and a composite of each of the O, A, and C horizons. The Ca, Fe, K, Mg, Na, S, Ti, Ag, As, Ba, Be, Bi, Cd, Ce, Co, Cr, Cs, Cu, Ga, In, La, Li, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Te, Th, Tl, U, V, W, Y, and Zn by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry following a near-total digestion in a mixture of HCl, HNO3, HClO4, and HF. Separate methods were used for Hg, Se, total C, and carbonate-C on this same size fraction. Only Ag, In, and Te had a large percentage of concentrations below the detection limit. Quality control (QC) of the analyses was monitored at three levels: the laboratory performing the analysis, the USGS QC officer, and the principal investigator for the study. This level of review resulted in an average of one QC sample for every 20 field samples, which proved to be minimally adequate for such a large-scale survey. Additional QC samples should be added to monitor within-batch quality to the extent that no more than 10 samples are analyzed between a QC sample. Only Cr (77%), Y (82%), and Sb (80%) fell outside the acceptable limits of accuracy (% recovery between 85 and 115%) because of likely residence in mineral phases resistant to the acid digestion. A separate sample of 0-5-cm material was collected at each site for determination of organic compounds. A subset of 73 of these samples was analyzed for a suite of

  15. 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

  16. 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)

  17. 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.

  18. 40 CFR 761.247 - Sample site selection for pipe segment removal.

    Science.gov (United States)

    2010-07-01

    ... end of the pipe segment. (3) If the pipe segment is cut with a saw or other mechanical device, take..., take samples from a total of seven segments. (A) Sample the first and last segments removed. (B) Select... total length for purposes of disposal, take samples of each segment that is 1/2 mile distant from the...

  19. 40 CFR 761.306 - Sampling 1 meter square surfaces by random selection of halves.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling 1 meter square surfaces by...(b)(3) § 761.306 Sampling 1 meter square surfaces by random selection of halves. (a) Divide each 1 meter square portion where it is necessary to collect a surface wipe test sample into two equal (or as...

  20. Pesticide contamination of fruits and vegetables - A market basket survey from selected regions in Ghana

    International Nuclear Information System (INIS)

    Asiedu, Eric

    2013-07-01

    A market - basket survey was carried out with the aim of determining the concentration levels of pesticides, in lettuce, garden eggs, pineapple and mango from some selected regions in Ghana and to assess the potential health risk associated with exposure to the pesticide residues from fruits and vegetables consumption. A total of 192 fresh samples of fruits and vegetables were randomly collected under normal purchase conditions from 12 major towns and cities in the three regions of Ghana. The samples were extracted and analyzed for organophosphates, synthetic pyrethroids and organo chlorine pesticides. The percentage of samples of fruits and vegetables with pesticide residues in Lettuce, Garden eggs, Pineapple and Mango were 52%, 40%, 45%, 48% respectively and concentrations of pesticides did not vary significantly in samples as well as the sampling areas (p>0.05) even though there were differences in residual concentrations of pesticides . The differences in residual concentrations of pesticides could be due to different agricultural practices adopted by farmers and also accessibility of the pesticides. The average residue concentrations range from 0.01-0.45 mg/kg, 0.01-0.30 mg/kg and 0.01-1.27 mg/kg for organophosphates, synthetic pyrethroids and organo chlorine pesticides respectively. Lindane, chloropyrifos and cypermethrin were the most frequent organo chlorine, organophosphate and synthetic pyrethroid pesticides respectively while lettuce was the most frequently contaminated sample. Comparing the concentration levels of organo chlorine pesticides residue with the maximum residue limits (MRLs) adopted by the FAO/WHO Codex Alimentarious Commission shows that some of the fruits and vegetables sold on Ghanaian markets are contaminated even though the levels are generally low. Health risk analysis indicates that heptachlor in particular may be of public concern since its concentration levels exceeded the reference dose in all the four different types of samples

  1. Data Quality Objectives For Selecting Waste Samples To Test The Fluid Bed Steam Reformer Test

    International Nuclear Information System (INIS)

    Banning, D.L.

    2010-01-01

    This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Fluid Bed Steam Reformer testing. The type, quantity and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluid bed steam reformer (FBSR). A determination of the adequacy of the FBSR process to treat Hanford tank waste is required. The initial step in determining the adequacy of the FBSR process is to select archived waste samples from the 222-S Laboratory that will be used to test the FBSR process. Analyses of the selected samples will be required to confirm the samples meet the testing criteria.

  2. 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.

  3. 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.

  4. Some fuzzy techniques for staff selection process: A survey

    Science.gov (United States)

    Md Saad, R.; Ahmad, M. Z.; Abu, M. S.; Jusoh, M. S.

    2013-04-01

    With high level of business competition, it is vital to have flexible staff that are able to adapt themselves with work circumstances. However, staff selection process is not an easy task to be solved, even when it is tackled in a simplified version containing only a single criterion and a homogeneous skill. When multiple criteria and various skills are involved, the problem becomes much more complicated. In adddition, there are some information that could not be measured precisely. This is patently obvious when dealing with opinions, thoughts, feelings, believes, etc. One possible tool to handle this issue is by using fuzzy set theory. Therefore, the objective of this paper is to review the existing fuzzy techniques for solving staff selection process. It classifies several existing research methods and identifies areas where there is a gap and need further research. Finally, this paper concludes by suggesting new ideas for future research based on the gaps identified.

  5. National Survey of Prison Health Care: Selected Findings.

    Science.gov (United States)

    Maruschak, Laura; Chari, Karishma A; Simon, Alan E; DeFrances, Carol J

    2016-07-01

    This report presents selected findings on the provision of health care services in U.S. state prisons. Findings on admissions testing for infectious disease, cardiovascular risk factors, and mental health conditions, as well as the location of the provision of care and utilization of telemedicine are all included. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

  6. On a Robust MaxEnt Process Regression Model with Sample-Selection

    Directory of Open Access Journals (Sweden)

    Hea-Jung Kim

    2018-04-01

    Full Text Available In a regression analysis, a sample-selection bias arises when a dependent variable is partially observed as a result of the sample selection. This study introduces a Maximum Entropy (MaxEnt process regression model that assumes a MaxEnt prior distribution for its nonparametric regression function and finds that the MaxEnt process regression model includes the well-known Gaussian process regression (GPR model as a special case. Then, this special MaxEnt process regression model, i.e., the GPR model, is generalized to obtain a robust sample-selection Gaussian process regression (RSGPR model that deals with non-normal data in the sample selection. Various properties of the RSGPR model are established, including the stochastic representation, distributional hierarchy, and magnitude of the sample-selection bias. These properties are used in the paper to develop a hierarchical Bayesian methodology to estimate the model. This involves a simple and computationally feasible Markov chain Monte Carlo algorithm that avoids analytical or numerical derivatives of the log-likelihood function of the model. The performance of the RSGPR model in terms of the sample-selection bias correction, robustness to non-normality, and prediction, is demonstrated through results in simulations that attest to its good finite-sample performance.

  7. 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.

  8. 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.

  9. A novel heterogeneous training sample selection method on space-time adaptive processing

    Science.gov (United States)

    Wang, Qiang; Zhang, Yongshun; Guo, Yiduo

    2018-04-01

    The performance of ground target detection about space-time adaptive processing (STAP) decreases when non-homogeneity of clutter power is caused because of training samples contaminated by target-like signals. In order to solve this problem, a novel nonhomogeneous training sample selection method based on sample similarity is proposed, which converts the training sample selection into a convex optimization problem. Firstly, the existing deficiencies on the sample selection using generalized inner product (GIP) are analyzed. Secondly, the similarities of different training samples are obtained by calculating mean-hausdorff distance so as to reject the contaminated training samples. Thirdly, cell under test (CUT) and the residual training samples are projected into the orthogonal subspace of the target in the CUT, and mean-hausdorff distances between the projected CUT and training samples are calculated. Fourthly, the distances are sorted in order of value and the training samples which have the bigger value are selective preference to realize the reduced-dimension. Finally, simulation results with Mountain-Top data verify the effectiveness of the proposed method.

  10. A survey of the state and status of physical education in selected ...

    African Journals Online (AJOL)

    A survey of the state and status of physical education in selected primary schools in ... Physical Development and movement in the Foundation Phase (FP) and the ... Keywords: Education, Physical Education, Life Orientation, Curriculum 2005, ...

  11. 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.

  12. Selecting Sample Preparation Workflows for Mass Spectrometry-Based Proteomic and Phosphoproteomic Analysis of Patient Samples with Acute Myeloid Leukemia.

    Science.gov (United States)

    Hernandez-Valladares, Maria; Aasebø, Elise; Selheim, Frode; Berven, Frode S; Bruserud, Øystein

    2016-08-22

    Global mass spectrometry (MS)-based proteomic and phosphoproteomic studies of acute myeloid leukemia (AML) biomarkers represent a powerful strategy to identify and confirm proteins and their phosphorylated modifications that could be applied in diagnosis and prognosis, as a support for individual treatment regimens and selection of patients for bone marrow transplant. MS-based studies require optimal and reproducible workflows that allow a satisfactory coverage of the proteome and its modifications. Preparation of samples for global MS analysis is a crucial step and it usually requires method testing, tuning and optimization. Different proteomic workflows that have been used to prepare AML patient samples for global MS analysis usually include a standard protein in-solution digestion procedure with a urea-based lysis buffer. The enrichment of phosphopeptides from AML patient samples has previously been carried out either with immobilized metal affinity chromatography (IMAC) or metal oxide affinity chromatography (MOAC). We have recently tested several methods of sample preparation for MS analysis of the AML proteome and phosphoproteome and introduced filter-aided sample preparation (FASP) as a superior methodology for the sensitive and reproducible generation of peptides from patient samples. FASP-prepared peptides can be further fractionated or IMAC-enriched for proteome or phosphoproteome analyses. Herein, we will review both in-solution and FASP-based sample preparation workflows and encourage the use of the latter for the highest protein and phosphorylation coverage and reproducibility.

  13. Selecting Sample Preparation Workflows for Mass Spectrometry-Based Proteomic and Phosphoproteomic Analysis of Patient Samples with Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Maria Hernandez-Valladares

    2016-08-01

    Full Text Available Global mass spectrometry (MS-based proteomic and phosphoproteomic studies of acute myeloid leukemia (AML biomarkers represent a powerful strategy to identify and confirm proteins and their phosphorylated modifications that could be applied in diagnosis and prognosis, as a support for individual treatment regimens and selection of patients for bone marrow transplant. MS-based studies require optimal and reproducible workflows that allow a satisfactory coverage of the proteome and its modifications. Preparation of samples for global MS analysis is a crucial step and it usually requires method testing, tuning and optimization. Different proteomic workflows that have been used to prepare AML patient samples for global MS analysis usually include a standard protein in-solution digestion procedure with a urea-based lysis buffer. The enrichment of phosphopeptides from AML patient samples has previously been carried out either with immobilized metal affinity chromatography (IMAC or metal oxide affinity chromatography (MOAC. We have recently tested several methods of sample preparation for MS analysis of the AML proteome and phosphoproteome and introduced filter-aided sample preparation (FASP as a superior methodology for the sensitive and reproducible generation of peptides from patient samples. FASP-prepared peptides can be further fractionated or IMAC-enriched for proteome or phosphoproteome analyses. Herein, we will review both in-solution and FASP-based sample preparation workflows and encourage the use of the latter for the highest protein and phosphorylation coverage and reproducibility.

  14. Survey and selection of assessment methodologies for GAVE options

    International Nuclear Information System (INIS)

    Weterings, R.

    1999-05-01

    The Dutch government is interested in the possibilities for a market introduction of new gaseous and liquid energy carriers. To this purpose the GAVE-programme was recently set up. This study is carried out within the framework of the GAVE-programme and aims at the selection of methodologies for assessing the technological, economic, ecological and social perspectives of these new energy options (so-called GAVE-options). Based on the results of these assessments the Dutch ministries of Housing, Planning and Environment (VROM) and Economic Affairs (EZ) will decide at the end of 1999 about starting demonstration projects of promising energy carriers

  15. 6. Label-free selective plane illumination microscopy of tissue samples

    Directory of Open Access Journals (Sweden)

    Muteb Alharbi

    2017-10-01

    Conclusion: Overall this method meets the demands of the current needs for 3D imaging tissue samples in a label-free manner. Label-free Selective Plane Microscopy directly provides excellent information about the structure of the tissue samples. This work has highlighted the superiority of Label-free Selective Plane Microscopy to current approaches to label-free 3D imaging of tissue.

  16. Accounting for animal movement in estimation of resource selection functions: sampling and data analysis.

    Science.gov (United States)

    Forester, James D; Im, Hae Kyung; Rathouz, Paul J

    2009-12-01

    Patterns of resource selection by animal populations emerge as a result of the behavior of many individuals. Statistical models that describe these population-level patterns of habitat use can miss important interactions between individual animals and characteristics of their local environment; however, identifying these interactions is difficult. One approach to this problem is to incorporate models of individual movement into resource selection models. To do this, we propose a model for step selection functions (SSF) that is composed of a resource-independent movement kernel and a resource selection function (RSF). We show that standard case-control logistic regression may be used to fit the SSF; however, the sampling scheme used to generate control points (i.e., the definition of availability) must be accommodated. We used three sampling schemes to analyze simulated movement data and found that ignoring sampling and the resource-independent movement kernel yielded biased estimates of selection. The level of bias depended on the method used to generate control locations, the strength of selection, and the spatial scale of the resource map. Using empirical or parametric methods to sample control locations produced biased estimates under stronger selection; however, we show that the addition of a distance function to the analysis substantially reduced that bias. Assuming a uniform availability within a fixed buffer yielded strongly biased selection estimates that could be corrected by including the distance function but remained inefficient relative to the empirical and parametric sampling methods. As a case study, we used location data collected from elk in Yellowstone National Park, USA, to show that selection and bias may be temporally variable. Because under constant selection the amount of bias depends on the scale at which a resource is distributed in the landscape, we suggest that distance always be included as a covariate in SSF analyses. This approach to

  17. 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...

  18. 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)

  19. 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.

  20. 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…

  1. 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.

  2. 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

  3. 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

  4. Optimal Selection of the Sampling Interval for Estimation of Modal Parameters by an ARMA- Model

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    1993-01-01

    Optimal selection of the sampling interval for estimation of the modal parameters by an ARMA-model for a white noise loaded structure modelled as a single degree of- freedom linear mechanical system is considered. An analytical solution for an optimal uniform sampling interval, which is optimal...

  5. Correlations fo Sc, rare earths and other elements in selected rock samples from Arrua-i

    Energy Technology Data Exchange (ETDEWEB)

    Facetti, J F; Prats, M [Asuncion Nacional Univ. (Paraguay). Inst. de Ciencias

    1972-01-01

    The Sc and Eu contents in selected rocks samples from the stock of Arrua-i have been determined and correlations established with other elements and with the relative amount of some rare earths. These correlations suggest metasomatic phenomena for the formation of the rock samples.

  6. HOT-DUST-POOR QUASARS IN MID-INFRARED AND OPTICALLY SELECTED SAMPLES

    International Nuclear Information System (INIS)

    Hao Heng; Elvis, Martin; Civano, Francesca; Lawrence, Andy

    2011-01-01

    We show that the hot-dust-poor (HDP) quasars, originally found in the X-ray-selected XMM-COSMOS type 1 active galactic nucleus (AGN) sample, are just as common in two samples selected at optical/infrared wavelengths: the Richards et al. Spitzer/SDSS sample (8.7% ± 2.2%) and the Palomar-Green-quasar-dominated sample of Elvis et al. (9.5% ± 5.0%). The properties of the HDP quasars in these two samples are consistent with the XMM-COSMOS sample, except that, at the 99% (∼ 2.5σ) significance, a larger proportion of the HDP quasars in the Spitzer/SDSS sample have weak host galaxy contributions, probably due to the selection criteria used. Either the host dust is destroyed (dynamically or by radiation) or is offset from the central black hole due to recoiling. Alternatively, the universality of HDP quasars in samples with different selection methods and the continuous distribution of dust covering factor in type 1 AGNs suggest that the range of spectral energy distributions could be related to the range of tilts in warped fueling disks, as in the model of Lawrence and Elvis, with HDP quasars having relatively small warps.

  7. Correlations fo Sc, rare earths and other elements in selected rock samples from Arrua-i

    International Nuclear Information System (INIS)

    Facetti, J.F.; Prats, M.

    1972-01-01

    The Sc and Eu contents in selected rocks samples from the stock of Arrua-i have been determined and correlations established with other elements and with the relative amount of some rare earths. These correlations suggest metasomatic phenomena for the formation of the rock samples

  8. Proposal for selecting an ore sample from mining shaft under Kvanefjeld

    International Nuclear Information System (INIS)

    Lund Clausen, F.

    1979-02-01

    Uranium ore recovered from the tunnel under Kvanefjeld (Greenland) will be processed in a pilot plant. Selection of a fully representative ore sample for both the whole area and single local sites is discussed. A FORTRAN program for ore distribution is presented, in order to enable correct sampling. (EG)

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Electromembrane extraction as a rapid and selective miniaturized sample preparation technique for biological fluids

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Pedersen-Bjergaard, Stig; Seip, Knut Fredrik

    2015-01-01

    This special report discusses the sample preparation method electromembrane extraction, which was introduced in 2006 as a rapid and selective miniaturized extraction method. The extraction principle is based on isolation of charged analytes extracted from an aqueous sample, across a thin film....... Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper....

  16. Data Quality Objectives For Selecting Waste Samples For Bench-Scale Reformer Treatability Studies

    International Nuclear Information System (INIS)

    Banning, D.L.

    2011-01-01

    This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Bench-Scale Reforming testing. The type, quantity, and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluidized bed steam reformer. A determination of the adequacy of the fluidized bed steam reformer process to treat Hanford tank waste is required. The initial step in determining the adequacy of the fluidized bed steam reformer process is to select archived waste samples from the 222-S Laboratory that will be used in a bench scale tests. Analyses of the selected samples will be required to confirm the samples meet the shipping requirements and for comparison to the bench scale reformer (BSR) test sample selection requirements.

  17. Eco-virological survey of Aedes mosquito larvae in selected dengue outbreak areas in Malaysia.

    Science.gov (United States)

    Rohani, A; Aidil Azahary, A R; Malinda, M; Zurainee, M N; Rozilawati, H; Wan Najdah, W M A; Lee, H L

    2014-12-01

    BACKGROUND & OBJECTIVESI: Transovarial transmission of dengue virus in the Aedes vectors is now a well-documented phenomenon reported from many parts of the endemic areas in the world, which played an important role in initiating and maintaining the outbreak in human populations. This study investigated the factors affecting breeding habitats and the relationship with transovarial dengue virus in larvae of Aedes aegypti and Ae. albopictus. Larval surveillance was conducted in dengue outbreak areas in Malaysia from 2008 until 2009. Sampling was carried out based on habitat type, water condition (substrate type), canopy coverage, temperature and pH at breeding habitats. RT-PCR was performed to detect presence of transovarial dengue virus in larvae collected in the study areas. A total of 789 breeding habitats were identified during this study and the majority of these breeding sites were plastic containers (57.46%). Aedes albopictus dominated most of the water condition surveyed, while Ae. aegypti indicated preference toward habitats with clear water. Aedes aegypti was selective in selecting ovipositional sites compared to Ae. albopictus where shaded areas were shown to be the most preferred. From a total of 363 mosquito larvae pools, 23 (6.3%) pools were positive for dengue virus where 18 of them were from Ae. albopictus and five were from Ae. aegypti mosquito larvae pools. This study indicated the presence of transovarial transmission of dengue virus in immature Ae. aegypti and Ae. albopictus in the field. This study also showed that combination of water conditions, canopy coverage, temperature and pH of breeding habitats were the factors affecting the larval population. The study suggested that larval survey programme could serve as a tool not only to monitor the local dengue vector distribution but also to provide objective information for taking appropriate action by the community against dengue vectors.

  18. Approaches to sampling and case selection in qualitative research: examples in the geography of health.

    Science.gov (United States)

    Curtis, S; Gesler, W; Smith, G; Washburn, S

    2000-04-01

    This paper focuses on the question of sampling (or selection of cases) in qualitative research. Although the literature includes some very useful discussions of qualitative sampling strategies, the question of sampling often seems to receive less attention in methodological discussion than questions of how data is collected or is analysed. Decisions about sampling are likely to be important in many qualitative studies (although it may not be an issue in some research). There are varying accounts of the principles applicable to sampling or case selection. Those who espouse 'theoretical sampling', based on a 'grounded theory' approach, are in some ways opposed to those who promote forms of 'purposive sampling' suitable for research informed by an existing body of social theory. Diversity also results from the many different methods for drawing purposive samples which are applicable to qualitative research. We explore the value of a framework suggested by Miles and Huberman [Miles, M., Huberman,, A., 1994. Qualitative Data Analysis, Sage, London.], to evaluate the sampling strategies employed in three examples of research by the authors. Our examples comprise three studies which respectively involve selection of: 'healing places'; rural places which incorporated national anti-malarial policies; young male interviewees, identified as either chronically ill or disabled. The examples are used to show how in these three studies the (sometimes conflicting) requirements of the different criteria were resolved, as well as the potential and constraints placed on the research by the selection decisions which were made. We also consider how far the criteria Miles and Huberman suggest seem helpful for planning 'sample' selection in qualitative research.

  19. Sejong Open Cluster Survey (SOS). 0. Target Selection and Data Analysis

    Science.gov (United States)

    Sung, Hwankyung; Lim, Beomdu; Bessell, Michael S.; Kim, Jinyoung S.; Hur, Hyeonoh; Chun, Moo-Young; Park, Byeong-Gon

    2013-06-01

    Star clusters are superb astrophysical laboratories containing cospatial and coeval samples of stars with similar chemical composition. We initiate the Sejong Open cluster Survey (SOS) - a project dedicated to providing homogeneous photometry of a large number of open clusters in the SAAO Johnson-Cousins' UBVI system. To achieve our main goal, we pay much attention to the observation of standard stars in order to reproduce the SAAO standard system. Many of our targets are relatively small sparse clusters that escaped previous observations. As clusters are considered building blocks of the Galactic disk, their physical properties such as the initial mass function, the pattern of mass segregation, etc. give valuable information on the formation and evolution of the Galactic disk. The spatial distribution of young open clusters will be used to revise the local spiral arm structure of the Galaxy. In addition, the homogeneous data can also be used to test stellar evolutionary theory, especially concerning rare massive stars. In this paper we present the target selection criteria, the observational strategy for accurate photometry, and the adopted calibrations for data analysis such as color-color relations, zero-age main sequence relations, Sp - M_V relations, Sp - T_{eff} relations, Sp - color relations, and T_{eff} - BC relations. Finally we provide some data analysis such as the determination of the reddening law, the membership selection criteria, and distance determination.

  20. Prevalence Survey of Selected Bovine Pathogens in Water Buffaloes in the North Region of Brazil

    Directory of Open Access Journals (Sweden)

    Jenevaldo Barbosa da Silva

    2014-01-01

    Full Text Available Although the largest buffalo herd in the occident is in the north region of Brazil, few studies have been conducted to assess the prevalence of selected parasitic diseases in buffalo herd. The present study was therefore conducted to investigate the epidemiological of Toxoplasma gondii, Neospora caninum, Anaplasma marginale, Babesia bigemina, and Babesia bovis in water buffaloes in the north region of Brazil. A total of 4796 buffalo blood samples were randomly collected from five provinces and simultaneously analyzed by the IFAT and ELISA. The serological prevalence of T. gondii and N. caninum was 41.3% and 55.5% in ELISA and 35.7% and 48.8% in IFAT, respectively. The overall prevalence of A. marginale, B. bovis, and B. bigemina was 63%, 25%, and 21% by ELISA and 50.0%, 22.5%, and 18.8% by IFAT, respectively. This study shows valuable information regarding the serological survey of selected bovine pathogens in water buffaloes in the north region of Brazil which will likely be very beneficial for the management and control programs of this disease.

  1. 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.

  2. 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.

  3. A Multiwavelength Study of a Sample of 70 μm Selected Galaxies in the COSMOS Field : I. Spectral Energy Distributions and Luminosities

    NARCIS (Netherlands)

    Kartaltepe, Jeyhan S.; Sanders, D. B.; Le Floc'h, E.; Frayer, D. T.; Aussel, H.; Arnouts, S.; Ilbert, O.; Salvato, M.; Scoville, N. Z.; Surace, J.; Yan, L.; Brusa, M.; Capak, P.; Caputi, K.; Carollo, C. M.; Civano, F.; Elvis, M.; Faure, C.; Hasinger, G.; Koekemoer, A. M.; Lee, N.; Lilly, S.; Liu, C. T.; McCracken, H. J.; Schinnerer, E.; Smolčić, V.; Taniguchi, Y.; Thompson, D. J.; Trump, J.

    We present a large robust sample of 1503 reliable and unconfused 70 μm selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, L IR (8-1000 μm), by finding the best-fit template

  4. 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.

  5. The Impact of Selection, Gene Conversion, and Biased Sampling on the Assessment of Microbial Demography.

    Science.gov (United States)

    Lapierre, Marguerite; Blin, Camille; Lambert, Amaury; Achaz, Guillaume; Rocha, Eduardo P C

    2016-07-01

    Recent studies have linked demographic changes and epidemiological patterns in bacterial populations using coalescent-based approaches. We identified 26 studies using skyline plots and found that 21 inferred overall population expansion. This surprising result led us to analyze the impact of natural selection, recombination (gene conversion), and sampling biases on demographic inference using skyline plots and site frequency spectra (SFS). Forward simulations based on biologically relevant parameters from Escherichia coli populations showed that theoretical arguments on the detrimental impact of recombination and especially natural selection on the reconstructed genealogies cannot be ignored in practice. In fact, both processes systematically lead to spurious interpretations of population expansion in skyline plots (and in SFS for selection). Weak purifying selection, and especially positive selection, had important effects on skyline plots, showing patterns akin to those of population expansions. State-of-the-art techniques to remove recombination further amplified these biases. We simulated three common sampling biases in microbiological research: uniform, clustered, and mixed sampling. Alone, or together with recombination and selection, they further mislead demographic inferences producing almost any possible skyline shape or SFS. Interestingly, sampling sub-populations also affected skyline plots and SFS, because the coalescent rates of populations and their sub-populations had different distributions. This study suggests that extreme caution is needed to infer demographic changes solely based on reconstructed genealogies. We suggest that the development of novel sampling strategies and the joint analyzes of diverse population genetic methods are strictly necessary to estimate demographic changes in populations where selection, recombination, and biased sampling are present. © The Author 2016. Published by Oxford University Press on behalf of the Society for

  6. Hybrid nested sampling algorithm for Bayesian model selection applied to inverse subsurface flow problems

    KAUST Repository

    Elsheikh, Ahmed H.

    2014-02-01

    A Hybrid Nested Sampling (HNS) algorithm is proposed for efficient Bayesian model calibration and prior model selection. The proposed algorithm combines, Nested Sampling (NS) algorithm, Hybrid Monte Carlo (HMC) sampling and gradient estimation using Stochastic Ensemble Method (SEM). NS is an efficient sampling algorithm that can be used for Bayesian calibration and estimating the Bayesian evidence for prior model selection. Nested sampling has the advantage of computational feasibility. Within the nested sampling algorithm, a constrained sampling step is performed. For this step, we utilize HMC to reduce the correlation between successive sampled states. HMC relies on the gradient of the logarithm of the posterior distribution, which we estimate using a stochastic ensemble method based on an ensemble of directional derivatives. SEM only requires forward model runs and the simulator is then used as a black box and no adjoint code is needed. The developed HNS algorithm is successfully applied for Bayesian calibration and prior model selection of several nonlinear subsurface flow problems. © 2013 Elsevier Inc.

  7. [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

  8. HICOSMO - cosmology with a complete sample of galaxy clusters - I. Data analysis, sample selection and luminosity-mass scaling relation

    Science.gov (United States)

    Schellenberger, G.; Reiprich, T. H.

    2017-08-01

    The X-ray regime, where the most massive visible component of galaxy clusters, the intracluster medium, is visible, offers directly measured quantities, like the luminosity, and derived quantities, like the total mass, to characterize these objects. The aim of this project is to analyse a complete sample of galaxy clusters in detail and constrain cosmological parameters, like the matter density, Ωm, or the amplitude of initial density fluctuations, σ8. The purely X-ray flux-limited sample (HIFLUGCS) consists of the 64 X-ray brightest galaxy clusters, which are excellent targets to study the systematic effects, that can bias results. We analysed in total 196 Chandra observations of the 64 HIFLUGCS clusters, with a total exposure time of 7.7 Ms. Here, we present our data analysis procedure (including an automated substructure detection and an energy band optimization for surface brightness profile analysis) that gives individually determined, robust total mass estimates. These masses are tested against dynamical and Planck Sunyaev-Zeldovich (SZ) derived masses of the same clusters, where good overall agreement is found with the dynamical masses. The Planck SZ masses seem to show a mass-dependent bias to our hydrostatic masses; possible biases in this mass-mass comparison are discussed including the Planck selection function. Furthermore, we show the results for the (0.1-2.4) keV luminosity versus mass scaling relation. The overall slope of the sample (1.34) is in agreement with expectations and values from literature. Splitting the sample into galaxy groups and clusters reveals, even after a selection bias correction, that galaxy groups exhibit a significantly steeper slope (1.88) compared to clusters (1.06).

  9. Ethnopharmacological survey: a selection strategy to identify medicinal plants for a local phytotherapy program

    Directory of Open Access Journals (Sweden)

    Flávia Liparini Pereira

    2012-06-01

    Full Text Available Ethnopharmacological studies are important for documenting and protecting cultural and traditional knowledge associated with the medical use of biodiversity. In this paper, we present a survey on medicinal plants used by locals in a community of Nova Viçosa, Viçosa, MG, Brazil, as a strategy to select medicinal plants for a phytotherapy-based local healthcare program. Eleven knowledgeable local informants were chosen by snowball sampling and interviewed about the use of medicinal plants. Plant samples were collected, herborised and then identified using traditional techniques and specialised literature. We sampled 107 medicinal plant species belonging to 86 genera and 39 families, predominantly Asteraceae with 16 species. Costus spicatus (Jacq. Sw, M. pulegium L., Rosmarinus officinalis L. and Ruta graveolens L. were found to have Consensus of Main Use corrected (CMUc values above 50%, which were in agreement with the traditional uses described by the informants. However, species with CMUc values equal to or above 20%, combined with the scientific information survey, were also used to select medicinal plants for the phytotherapy-based local healthcare program. The selection of medicinal plants based on the CMUc index from this particular community, in combination with the scientific survey, appears to be an effective strategy for the implementation of phytotherapy programs.Estudos etnofarmacológicos são importantes no registro e na preservação de conhecimentos de uma cultura tradicional associada ao uso medicinal da biodiversidade. No presente trabalho, foi realizado o levantamento das plantas medicinais utilizadas por conhecedores populares na comunidade de Nova Viçosa, Viçosa, Minas Gerais, Brasil, como ferramenta para auxiliar na seleção de espécies vegetais visando à implantação de um programa de fitoterapia local na comunidade estudada. Participaram 11 conhecedores escolhidos por amostragem Bola de Neve e submetidos a

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. SDSS-IV MaNGA: faint quenched galaxies - I. Sample selection and evidence for environmental quenching

    Science.gov (United States)

    Penny, Samantha J.; Masters, Karen L.; Weijmans, Anne-Marie; Westfall, Kyle B.; Bershady, Matthew A.; Bundy, Kevin; Drory, Niv; Falcón-Barroso, Jesús; Law, David; Nichol, Robert C.; Thomas, Daniel; Bizyaev, Dmitry; Brownstein, Joel R.; Freischlad, Gordon; Gaulme, Patrick; Grabowski, Katie; Kinemuchi, Karen; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Roman-Lopes, Alexandre; Pan, Kaike; Simmons, Audrey; Wake, David A.

    2016-11-01

    Using kinematic maps from the Sloan Digital Sky Survey (SDSS) Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, we reveal that the majority of low-mass quenched galaxies exhibit coherent rotation in their stellar kinematics. Our sample includes all 39 quenched low-mass galaxies observed in the first year of MaNGA. The galaxies are selected with Mr > -19.1, stellar masses 109 M⊙ 1.9. They lie on the size-magnitude and σ-luminosity relations for previously studied dwarf galaxies. Just six (15 ± 5.7 per cent) are found to have rotation speeds ve, rot 5 × 1010 M⊙), supporting the hypothesis that galaxy-galaxy or galaxy-group interactions quench star formation in low-mass galaxies. The local bright galaxy density for our sample is ρproj = 8.2 ± 2.0 Mpc-2, compared to ρproj = 2.1 ± 0.4 Mpc-2 for a star-forming comparison sample, confirming that the quenched low-mass galaxies are preferentially found in higher density environments.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Climate Change and Agricultural Productivity in Sub-Saharan Africa: A Spatial Sample Selection Model

    NARCIS (Netherlands)

    Ward, P.S.; Florax, R.J.G.M.; Flores-Lagunes, A.

    2014-01-01

    Using spatially explicit data, we estimate a cereal yield response function using a recently developed estimator for spatial error models when endogenous sample selection is of concern. Our results suggest that yields across Sub-Saharan Africa will decline with projected climatic changes, and that

  5. Decomposing the Gender Wage Gap in the Netherlands with Sample Selection Adjustments

    NARCIS (Netherlands)

    Albrecht, James; Vuuren, van Aico; Vroman, Susan

    2004-01-01

    In this paper, we use quantile regression decomposition methods to analyzethe gender gap between men and women who work full time in the Nether-lands. Because the fraction of women working full time in the Netherlands isquite low, sample selection is a serious issue. In addition to shedding light

  6. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo

    NARCIS (Netherlands)

    Papachroni, D.; Graikou, K.; Kosalec, I.; Damianakos, H.; Ingram, V.J.; Chinou, I.

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their

  7. Gender Wage Gap : A Semi-Parametric Approach With Sample Selection Correction

    NARCIS (Netherlands)

    Picchio, M.; Mussida, C.

    2010-01-01

    Sizeable gender differences in employment rates are observed in many countries. Sample selection into the workforce might therefore be a relevant issue when estimating gender wage gaps. This paper proposes a new semi-parametric estimator of densities in the presence of covariates which incorporates

  8. Testing the normality assumption in the sample selection model with an application to travel demand

    NARCIS (Netherlands)

    van der Klaauw, B.; Koning, R.H.

    2003-01-01

    In this article we introduce a test for the normality assumption in the sample selection model. The test is based on a flexible parametric specification of the density function of the error terms in the model. This specification follows a Hermite series with bivariate normality as a special case.

  9. Testing the normality assumption in the sample selection model with an application to travel demand

    NARCIS (Netherlands)

    van der Klauw, B.; Koning, R.H.

    In this article we introduce a test for the normality assumption in the sample selection model. The test is based on a flexible parametric specification of the density function of the error terms in the model. This specification follows a Hermite series with bivariate normality as a special case.

  10. Principal Stratification in sample selection problems with non normal error terms

    DEFF Research Database (Denmark)

    Rocci, Roberto; Mellace, Giovanni

    The aim of the paper is to relax distributional assumptions on the error terms, often imposed in parametric sample selection models to estimate causal effects, when plausible exclusion restrictions are not available. Within the principal stratification framework, we approximate the true distribut...... an application to the Job Corps training program....

  11. Selection of reference genes for tissue/organ samples on day 3 fifth-instar larvae in silkworm, Bombyx mori.

    Science.gov (United States)

    Wang, Genhong; Chen, Yanfei; Zhang, Xiaoying; Bai, Bingchuan; Yan, Hao; Qin, Daoyuan; Xia, Qingyou

    2018-06-01

    The silkworm, Bombyx mori, is one of the world's most economically important insect. Surveying variations in gene expression among multiple tissue/organ samples will provide clues for gene function assignments and will be helpful for identifying genes related to economic traits or specific cellular processes. To ensure their accuracy, commonly used gene expression quantification methods require a set of stable reference genes for data normalization. In this study, 24 candidate reference genes were assessed in 10 tissue/organ samples of day 3 fifth-instar B. mori larvae using geNorm and NormFinder. The results revealed that, using the combination of the expression of BGIBMGA003186 and BGIBMGA008209 was the optimum choice for normalizing the expression data of the B. mori tissue/organ samples. The most stable gene, BGIBMGA003186, is recommended if just one reference gene is used. Moreover, the commonly used reference gene encoding cytoplasmic actin was the least appropriate reference gene of the samples investigated. The reliability of the selected reference genes was further confirmed by evaluating the expression profiles of two cathepsin genes. Our results may be useful for future studies involving the quantification of relative gene expression levels of different tissue/organ samples in B. mori. © 2018 Wiley Periodicals, Inc.

  12. Selection of nursing teaching strategies in mainland China: A questionnaire survey.

    Science.gov (United States)

    Zhou, HouXiu; Liu, MengJie; Zeng, Jing; Zhu, JingCi

    2016-04-01

    In nursing education, the traditional lecture and direct demonstration teaching method cannot cultivate the various skills that nursing students need. How to choose a more scientific and rational teaching method is a common concern for nursing educators worldwide. To investigate the basis for selecting teaching methods among nursing teachers in mainland China, the factors affecting the selection of different teaching methods, and the application of different teaching methods in theoretical and skill-based nursing courses. Questionnaire survey. Seventy one nursing colleges from 28 provincial-level administrative regions in mainland China. Following the principle of voluntary informed consent, 262 nursing teachers were randomly selected through a nursing education network platform and a conference platform. The questionnaire contents included the basis for and the factors influencing the selection of nursing teaching methods, the participants' common teaching methods, and the teaching experience of the surveyed nursing teachers. The questionnaires were distributed through the network or conference platform, and the data were analyzed by SPSS 17.0 software. The surveyed nursing teachers selected teaching methods mainly based on the characteristics of the teaching content, the characteristics of the students, and their previous teaching experiences. The factors affecting the selection of teaching methods mainly included large class sizes, limited class time, and limited examination formats. The surveyed nursing teachers primarily used lectures to teach theory courses and the direct demonstration method to teach skills courses, and the application frequencies of these two teaching methods were significantly higher than those of other teaching methods (P=0.000). More attention should be paid to the selection of nursing teaching methods. Every teacher should strategically choose teaching methods before each lesson, and nursing education training focused on selecting

  13. The lack of selection bias in a snowball sampled case-control study on drug abuse.

    Science.gov (United States)

    Lopes, C S; Rodrigues, L C; Sichieri, R

    1996-12-01

    Friend controls in matched case-control studies can be a potential source of bias based on the assumption that friends are more likely to share exposure factors. This study evaluates the role of selection bias in a case-control study that used the snowball sampling method based on friendship for the selection of cases and controls. The cases selected fro the study were drug abusers located in the community. Exposure was defined by the presence of at least one psychiatric diagnosis. Psychiatric and drug abuse/dependence diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Cases and controls were matched on sex, age and friendship. The measurement of selection bias was made through the comparison of the proportion of exposed controls selected by exposed cases (p1) with the proportion of exposed controls selected by unexposed cases (p2). If p1 = p2 then, selection bias should not occur. The observed distribution of the 185 matched pairs having at least one psychiatric disorder showed a p1 value of 0.52 and a p2 value of 0.51, indicating no selection bias in this study. Our findings support the idea that the use of friend controls can produce a valid basis for a case-control study.

  14. COMMON PROPER-MOTION WIDE WHITE DWARF BINARIES SELECTED FROM THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Andrews, Jeff J.; Agüeros, Marcel A.; Belczynski, Krzysztof; Dhital, Saurav; Kleinman, S. J.; West, Andrew A.

    2012-01-01

    Wide binaries made up of two white dwarfs (WDs) receive far less attention than their tight counterparts. However, our tests using the binary population synthesis code StarTrack indicate that, for any set of reasonable initial conditions, there exists a significant observable population of double white dwarfs (WDWDs) with orbital separations of 10 2 -10 5 AU. We adapt the technique of Dhital et al. to search for candidate common proper-motion WD companions separated by 12,000 spectroscopically confirmed hydrogen-atmosphere WDs recently identified in the Sloan Digital Sky Survey. Using two techniques to separate random alignments from high-confidence pairs, we find nine new high-probability wide WDWDs and confirm three previously identified candidate wide WDWDs. This brings the number of known wide WDWDs to 45; our new pairs are a significant addition to the sample, especially at small proper motions ( –1 ) and large angular separations (>10''). Spectroscopic follow-up and an extension of this method to a larger, photometrically selected set of SDSS WDs may eventually produce a large enough dataset for WDWDs to realize their full potential as testbeds for theories of stellar evolution.

  15. COMMON PROPER-MOTION WIDE WHITE DWARF BINARIES SELECTED FROM THE SLOAN DIGITAL SKY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Jeff J.; Agueeros, Marcel A. [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Belczynski, Krzysztof [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Dhital, Saurav [Department of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Center, Nashville, TN 37235 (United States); Kleinman, S. J. [Gemini Observatory, Northern Operations Center, Hilo, HI 96720 (United States); West, Andrew A. [Department of Astronomy, Boston University, 725 Commonwealth Ave, Boston, MA 02215 (United States)

    2012-10-01

    Wide binaries made up of two white dwarfs (WDs) receive far less attention than their tight counterparts. However, our tests using the binary population synthesis code StarTrack indicate that, for any set of reasonable initial conditions, there exists a significant observable population of double white dwarfs (WDWDs) with orbital separations of 10{sup 2}-10{sup 5} AU. We adapt the technique of Dhital et al. to search for candidate common proper-motion WD companions separated by <10' around the >12,000 spectroscopically confirmed hydrogen-atmosphere WDs recently identified in the Sloan Digital Sky Survey. Using two techniques to separate random alignments from high-confidence pairs, we find nine new high-probability wide WDWDs and confirm three previously identified candidate wide WDWDs. This brings the number of known wide WDWDs to 45; our new pairs are a significant addition to the sample, especially at small proper motions (<200 mas yr{sup -1}) and large angular separations (>10''). Spectroscopic follow-up and an extension of this method to a larger, photometrically selected set of SDSS WDs may eventually produce a large enough dataset for WDWDs to realize their full potential as testbeds for theories of stellar evolution.

  16. Sample selection based on kernel-subclustering for the signal reconstruction of multifunctional sensors

    International Nuclear Information System (INIS)

    Wang, Xin; Wei, Guo; Sun, Jinwei

    2013-01-01

    The signal reconstruction methods based on inverse modeling for the signal reconstruction of multifunctional sensors have been widely studied in recent years. To improve the accuracy, the reconstruction methods have become more and more complicated because of the increase in the model parameters and sample points. However, there is another factor that affects the reconstruction accuracy, the position of the sample points, which has not been studied. A reasonable selection of the sample points could improve the signal reconstruction quality in at least two ways: improved accuracy with the same number of sample points or the same accuracy obtained with a smaller number of sample points. Both ways are valuable for improving the accuracy and decreasing the workload, especially for large batches of multifunctional sensors. In this paper, we propose a sample selection method based on kernel-subclustering distill groupings of the sample data and produce the representation of the data set for inverse modeling. The method calculates the distance between two data points based on the kernel-induced distance instead of the conventional distance. The kernel function is a generalization of the distance metric by mapping the data that are non-separable in the original space into homogeneous groups in the high-dimensional space. The method obtained the best results compared with the other three methods in the simulation. (paper)

  17. 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.

  18. New sorbent materials for selective extraction of cocaine and benzoylecgonine from human urine samples.

    Science.gov (United States)

    Bujak, Renata; Gadzała-Kopciuch, Renata; Nowaczyk, Alicja; Raczak-Gutknecht, Joanna; Kordalewska, Marta; Struck-Lewicka, Wiktoria; Waszczuk-Jankowska, Małgorzata; Tomczak, Ewa; Kaliszan, Michał; Buszewski, Bogusław; Markuszewski, Michał J

    2016-02-20

    An increase in cocaine consumption has been observed in Europe during the last decade. Benzoylecgonine, as a main urinary metabolite of cocaine in human, is so far the most reliable marker of cocaine consumption. Determination of cocaine and its metabolite in complex biological samples as urine or blood, requires efficient and selective sample pretreatment. In this preliminary study, the newly synthesized sorbent materials were proposed for selective extraction of cocaine and benzoylecgonine from urine samples. Application of these sorbent media allowed to determine cocaine and benzoylecgonine in urine samples at the concentration level of 100ng/ml with good recovery values as 81.7%±6.6 and 73.8%±4.2, respectively. The newly synthesized materials provided efficient, inexpensive and selective extraction of both cocaine and benzoylecgonine from urine samples, which can consequently lead to an increase of the sensitivity of the current available screening diagnostic tests. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Assessment of selected contaminants in streambed- and suspended-sediment samples collected in Bexar County, Texas, 2007-09

    Science.gov (United States)

    Wilson, Jennifer T.

    2011-01-01

    Elevated concentrations of sediment-associated contaminants are typically associated with urban areas such as San Antonio, Texas, in Bexar County, the seventh most populous city in the United States. This report describes an assessment of selected sediment-associated contaminants in samples collected in Bexar County from sites on the following streams: Medio Creek, Medina River, Elm Creek, Martinez Creek, Chupaderas Creek, Leon Creek, Salado Creek, and San Antonio River. During 2007-09, the U.S. Geological Survey periodically collected surficial streambed-sediment samples during base flow and suspended-sediment (large-volume suspended-sediment) samples from selected streams during stormwater runoff. All sediment samples were analyzed for major and trace elements and for organic compounds including halogenated organic compounds and polycyclic aromatic hydrocarbons (PAHs). Selected contaminants in streambed and suspended sediments in watersheds of the eight major streams in Bexar County were assessed by using a variety of methods—observations of occurrence and distribution, comparison to sediment-quality guidelines and data from previous studies, statistical analyses, and source indicators. Trace elements concentrations were low compared to the consensus-based sediment-quality guidelines threshold effect concentration (TEC) and probable effect concentration (PEC). Trace element concentrations were greater than the TEC in 28 percent of the samples and greater than the PEC in 1.5 percent of the samples. Chromium concentrations exceeded sediment-quality guidelines more frequently than concentrations of any other constituents analyzed in this study (greater than the TEC in 69 percent of samples and greater than the PEC in 8 percent of samples). Mean trace element concentrations generally are lower in Bexar County samples compared to concentrations in samples collected during previous studies in the Austin and Fort Worth, Texas, areas, but considering the relatively

  20. Imaging a Large Sample with Selective Plane Illumination Microscopy Based on Multiple Fluorescent Microsphere Tracking

    Science.gov (United States)

    Ryu, Inkeon; Kim, Daekeun

    2018-04-01

    A typical selective plane illumination microscopy (SPIM) image size is basically limited by the field of view, which is a characteristic of the objective lens. If an image larger than the imaging area of the sample is to be obtained, image stitching, which combines step-scanned images into a single panoramic image, is required. However, accurately registering the step-scanned images is very difficult because the SPIM system uses a customized sample mount where uncertainties for the translational and the rotational motions exist. In this paper, an image registration technique based on multiple fluorescent microsphere tracking is proposed in the view of quantifying the constellations and measuring the distances between at least two fluorescent microspheres embedded in the sample. Image stitching results are demonstrated for optically cleared large tissue with various staining methods. Compensation for the effect of the sample rotation that occurs during the translational motion in the sample mount is also discussed.

  1. Transfer function design based on user selected samples for intuitive multivariate volume exploration

    KAUST Repository

    Zhou, Liang; Hansen, Charles

    2013-01-01

    Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.

  2. Transfer function design based on user selected samples for intuitive multivariate volume exploration

    KAUST Repository

    Zhou, Liang

    2013-02-01

    Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.

  3. Passive sampling of selected endocrine disrupting compounds using polar organic chemical integrative samplers

    International Nuclear Information System (INIS)

    Arditsoglou, Anastasia; Voutsa, Dimitra

    2008-01-01

    Two types of polar organic chemical integrative samplers (pharmaceutical POCIS and pesticide POCIS) were examined for their sampling efficiency of selected endocrine disrupting compounds (EDCs). Laboratory-based calibration of POCISs was conducted by exposing them at high and low concentrations of 14 EDCs (4-alkyl-phenols, their ethoxylate oligomers, bisphenol A, selected estrogens and synthetic steroids) for different time periods. The kinetic studies showed an integrative uptake up to 28 days. The sampling rates for the individual compounds were obtained. The use of POCISs could result in an integrative approach to the quality status of the aquatic systems especially in the case of high variation of water concentrations of EDCs. The sampling efficiency of POCISs under various field conditions was assessed after their deployment in different aquatic environments. - Calibration and field performance of polar organic integrative samplers for monitoring EDCs in aquatic environments

  4. Semiparametric efficient and robust estimation of an unknown symmetric population under arbitrary sample selection bias

    KAUST Repository

    Ma, Yanyuan

    2013-09-01

    We propose semiparametric methods to estimate the center and shape of a symmetric population when a representative sample of the population is unavailable due to selection bias. We allow an arbitrary sample selection mechanism determined by the data collection procedure, and we do not impose any parametric form on the population distribution. Under this general framework, we construct a family of consistent estimators of the center that is robust to population model misspecification, and we identify the efficient member that reaches the minimum possible estimation variance. The asymptotic properties and finite sample performance of the estimation and inference procedures are illustrated through theoretical analysis and simulations. A data example is also provided to illustrate the usefulness of the methods in practice. © 2013 American Statistical Association.

  5. 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...

  6. 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.

  7. A comprehensive survey on selective breeding programs and seed market in the European aquaculture fish industry

    NARCIS (Netherlands)

    Chavanne, Hervé; Janssen, K.P.E.; Hofherr, Johann; Contini, Franca; Haffray, P.; Komen, J.; Nielsen, E.E.; Bargelloni, L.

    2016-01-01

    The use of selective breeding is still relatively limited in aquaculture species. Information on such activities is sparse, hindering an overall evaluation of their success. Here, we report on the results of an online survey of the major aqua-culture breeding companies operating in Europe. Six main

  8. Deep far infrared ISOPHOT survey in "Selected Area 57" - I. Observations and source counts

    DEFF Research Database (Denmark)

    Linden-Vornle, M.J.D.; Nørgaard-Nielsen, Hans Ulrik; Jørgensen, H.E.

    2000-01-01

    We present here the results of a deep survey in a 0.4 deg(2) blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO1) at both 60 mu m and 90 mu m. The resulting sky maps have a spatial resolution of 15 x 23 arcsrc(2) per pixel which is much...

  9. 5 CFR 591.212 - How does OPM select survey items?

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false How does OPM select survey items? 591.212 Section 591.212 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ALLOWANCES AND DIFFERENTIALS Cost-of-Living Allowance and Post Differential-Nonforeign Areas Cost-Of-Living...

  10. 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)

  11. 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/

  12. 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

  13. 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).

  14. 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.

  15. Nested sampling algorithm for subsurface flow model selection, uncertainty quantification, and nonlinear calibration

    KAUST Repository

    Elsheikh, A. H.

    2013-12-01

    Calibration of subsurface flow models is an essential step for managing ground water aquifers, designing of contaminant remediation plans, and maximizing recovery from hydrocarbon reservoirs. We investigate an efficient sampling algorithm known as nested sampling (NS), which can simultaneously sample the posterior distribution for uncertainty quantification, and estimate the Bayesian evidence for model selection. Model selection statistics, such as the Bayesian evidence, are needed to choose or assign different weights to different models of different levels of complexities. In this work, we report the first successful application of nested sampling for calibration of several nonlinear subsurface flow problems. The estimated Bayesian evidence by the NS algorithm is used to weight different parameterizations of the subsurface flow models (prior model selection). The results of the numerical evaluation implicitly enforced Occam\\'s razor where simpler models with fewer number of parameters are favored over complex models. The proper level of model complexity was automatically determined based on the information content of the calibration data and the data mismatch of the calibrated model.

  16. Dermatology Residency Selection Criteria with an Emphasis on Program Characteristics: A National Program Director Survey

    Directory of Open Access Journals (Sweden)

    Farzam Gorouhi

    2014-01-01

    Full Text Available Background. Dermatology residency programs are relatively diverse in their resident selection process. The authors investigated the importance of 25 dermatology residency selection criteria focusing on differences in program directors’ (PDs’ perception based on specific program demographics. Methods. This cross-sectional nationwide observational survey utilized a 41-item questionnaire that was developed by literature search, brainstorming sessions, and online expert reviews. The data were analyzed utilizing the reliability test, two-step clustering, and K-means methods as well as other methods. The main purpose of this study was to investigate the differences in PDs’ perception regarding the importance of the selection criteria based on program demographics. Results. Ninety-five out of 114 PDs (83.3% responded to the survey. The top five criteria for dermatology residency selection were interview, letters of recommendation, United States Medical Licensing Examination Step I scores, medical school transcripts, and clinical rotations. The following criteria were preferentially ranked based on different program characteristics: “advanced degrees,” “interest in academics,” “reputation of undergraduate and medical school,” “prior unsuccessful attempts to match,” and “number of publications.” Conclusions. Our survey provides up-to-date factual data on dermatology PDs’ perception in this regard. Dermatology residency programs may find the reported data useful in further optimizing their residency selection process.

  17. 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.

  18. 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.

  19. Soft X-Ray Observations of a Complete Sample of X-Ray--selected BL Lacertae Objects

    Science.gov (United States)

    Perlman, Eric S.; Stocke, John T.; Wang, Q. Daniel; Morris, Simon L.

    1996-01-01

    We present the results of ROSAT PSPC observations of the X-ray selected BL Lacertae objects (XBLs) in the complete Einstein Extended Medium Sensitivity Survey (EM MS) sample. None of the objects is resolved in their respective PSPC images, but all are easily detected. All BL Lac objects in this sample are well-fitted by single power laws. Their X-ray spectra exhibit a variety of spectral slopes, with best-fit energy power-law spectral indices between α = 0.5-2.3. The PSPC spectra of this sample are slightly steeper than those typical of flat ratio-spectrum quasars. Because almost all of the individual PSPC spectral indices are equal to or slightly steeper than the overall optical to X-ray spectral indices for these same objects, we infer that BL Lac soft X-ray continua are dominated by steep-spectrum synchrotron radiation from a broad X-ray jet, rather than flat-spectrum inverse Compton radiation linked to the narrower radio/millimeter jet. The softness of the X-ray spectra of these XBLs revives the possibility proposed by Guilbert, Fabian, & McCray (1983) that BL Lac objects are lineless because the circumnuclear gas cannot be heated sufficiently to permit two stable gas phases, the cooler of which would comprise the broad emission-line clouds. Because unified schemes predict that hard self-Compton radiation is beamed only into a small solid angle in BL Lac objects, the steep-spectrum synchrotron tail controls the temperature of the circumnuclear gas at r ≤ 1018 cm and prevents broad-line cloud formation. We use these new ROSAT data to recalculate the X-ray luminosity function and cosmological evolution of the complete EMSS sample by determining accurate K-corrections for the sample and estimating the effects of variability and the possibility of incompleteness in the sample. Our analysis confirms that XBLs are evolving "negatively," opposite in sense to quasars, with Ve/Va = 0.331±0.060. The statistically significant difference between the values for X

  20. Progressive sampling-based Bayesian optimization for efficient and automatic machine learning model selection.

    Science.gov (United States)

    Zeng, Xueqiang; Luo, Gang

    2017-12-01

    Machine learning is broadly used for clinical data analysis. Before training a model, a machine learning algorithm must be selected. Also, the values of one or more model parameters termed hyper-parameters must be set. Selecting algorithms and hyper-parameter values requires advanced machine learning knowledge and many labor-intensive manual iterations. To lower the bar to machine learning, miscellaneous automatic selection methods for algorithms and/or hyper-parameter values have been proposed. Existing automatic selection methods are inefficient on large data sets. This poses a challenge for using machine learning in the clinical big data era. To address the challenge, this paper presents progressive sampling-based Bayesian optimization, an efficient and automatic selection method for both algorithms and hyper-parameter values. We report an implementation of the method. We show that compared to a state of the art automatic selection method, our method can significantly reduce search time, classification error rate, and standard deviation of error rate due to randomization. This is major progress towards enabling fast turnaround in identifying high-quality solutions required by many machine learning-based clinical data analysis tasks.

  1. A GMM-Based Test for Normal Disturbances of the Heckman Sample Selection Model

    Directory of Open Access Journals (Sweden)

    Michael Pfaffermayr

    2014-10-01

    Full Text Available The Heckman sample selection model relies on the assumption of normal and homoskedastic disturbances. However, before considering more general, alternative semiparametric models that do not need the normality assumption, it seems useful to test this assumption. Following Meijer and Wansbeek (2007, the present contribution derives a GMM-based pseudo-score LM test on whether the third and fourth moments of the disturbances of the outcome equation of the Heckman model conform to those implied by the truncated normal distribution. The test is easy to calculate and in Monte Carlo simulations it shows good performance for sample sizes of 1000 or larger.

  2. Frequency-Selective Signal Sensing with Sub-Nyquist Uniform Sampling Scheme

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas

    2015-01-01

    In this paper the authors discuss a problem of acquisition and reconstruction of a signal polluted by adjacent- channel interference. The authors propose a method to find a sub-Nyquist uniform sampling pattern which allows for correct reconstruction of selected frequencies. The method is inspired...... by the Restricted Isometry Property, which is known from the field of compressed sensing. Then, compressed sensing is used to successfully reconstruct a wanted signal even if some of the uniform samples were randomly lost, e. g. due to ADC saturation. An experiment which tests the proposed method in practice...

  3. Out-of-pocket costs, primary care frequent attendance and sample selection: Estimates from a longitudinal cohort design.

    Science.gov (United States)

    Pymont, Carly; McNamee, Paul; Butterworth, Peter

    2018-03-20

    This paper examines the effect of out-of-pocket costs on subsequent frequent attendance in primary care using data from the Personality and Total Health (PATH) Through Life Project, a representative community cohort study from Canberra, Australia. The analysis sample comprised 1197 respondents with two or more GP consultations, and uses survey data linked to administrative health service use (Medicare) data which provides data on the number of consultations and out-of-pocket costs. Respondents identified in the highest decile of GP use in a year were defined as Frequent Attenders (FAs). Logistic regression models that did not account for potential selection effects showed that out-of-pocket costs incurred during respondents' prior two consultations were significantly associated with subsequent FA status. Respondents who incurred higher costs ($15-$35; or >$35) were less likely to become FAs than those who incurred no or low (attenders. Copyright © 2018. Published by Elsevier B.V.

  4. 40 CFR 761.308 - Sample selection by random number generation on any two-dimensional square grid.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sample selection by random number... § 761.79(b)(3) § 761.308 Sample selection by random number generation on any two-dimensional square... area created in accordance with paragraph (a) of this section, select two random numbers: one each for...

  5. Geochemistry of Selected Coal Samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    Science.gov (United States)

    Belkin, Harvey E.; Tewalt, Susan J.

    2007-01-01

    and ash (generally Indonesia although, at present, there are concerns about the strong need for a major revision in mining laws and foreign investment policies (Wahju, 2004; United States Embassy Jakarta, 2004). The World Coal Quality Inventory (WoCQI) program of the U.S. Geological Survey (Tewalt and others, 2005) is a cooperative project with about 50 countries (out of 70 coal-producing countries world-wide). The WoCQI initiative has collected and published extensive coal quality data from the world's largest coal producers and consumers. The important aspects of the WoCQI program are; (1) samples from active mines are collected, (2) the data have a high degree of internal consistency with a broad array of coal quality parameters, and (3) the data are linked to GIS and available through the world-wide-web. The coal quality parameters include proximate and ultimate analysis, sulfur forms, major-, minor-, and trace-element concentrations and various technological tests. This report contains geochemical data from a selected group of Indonesian coal samples from a range of coal types, localities, and ages collected for the WoCQI program.

  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. Criteria for selecting implementation science theories and frameworks: results from an international survey

    Directory of Open Access Journals (Sweden)

    Sarah A. Birken

    2017-10-01

    Full Text Available Abstract Background Theories provide a synthesizing architecture for implementation science. The underuse, superficial use, and misuse of theories pose a substantial scientific challenge for implementation science and may relate to challenges in selecting from the many theories in the field. Implementation scientists may benefit from guidance for selecting a theory for a specific study or project. Understanding how implementation scientists select theories will help inform efforts to develop such guidance. Our objective was to identify which theories implementation scientists use, how they use theories, and the criteria used to select theories. Methods We identified initial lists of uses and criteria for selecting implementation theories based on seminal articles and an iterative consensus process. We incorporated these lists into a self-administered survey for completion by self-identified implementation scientists. We recruited potential respondents at the 8th Annual Conference on the Science of Dissemination and Implementation in Health and via several international email lists. We used frequencies and percentages to report results. Results Two hundred twenty-three implementation scientists from 12 countries responded to the survey. They reported using more than 100 different theories spanning several disciplines. Respondents reported using theories primarily to identify implementation determinants, inform data collection, enhance conceptual clarity, and guide implementation planning. Of the 19 criteria presented in the survey, the criteria used by the most respondents to select theory included analytic level (58%, logical consistency/plausibility (56%, empirical support (53%, and description of a change process (54%. The criteria used by the fewest respondents included fecundity (10%, uniqueness (12%, and falsifiability (15%. Conclusions Implementation scientists use a large number of criteria to select theories, but there is little

  8. Criteria for selecting implementation science theories and frameworks: results from an international survey.

    Science.gov (United States)

    Birken, Sarah A; Powell, Byron J; Shea, Christopher M; Haines, Emily R; Alexis Kirk, M; Leeman, Jennifer; Rohweder, Catherine; Damschroder, Laura; Presseau, Justin

    2017-10-30

    Theories provide a synthesizing architecture for implementation science. The underuse, superficial use, and misuse of theories pose a substantial scientific challenge for implementation science and may relate to challenges in selecting from the many theories in the field. Implementation scientists may benefit from guidance for selecting a theory for a specific study or project. Understanding how implementation scientists select theories will help inform efforts to develop such guidance. Our objective was to identify which theories implementation scientists use, how they use theories, and the criteria used to select theories. We identified initial lists of uses and criteria for selecting implementation theories based on seminal articles and an iterative consensus process. We incorporated these lists into a self-administered survey for completion by self-identified implementation scientists. We recruited potential respondents at the 8th Annual Conference on the Science of Dissemination and Implementation in Health and via several international email lists. We used frequencies and percentages to report results. Two hundred twenty-three implementation scientists from 12 countries responded to the survey. They reported using more than 100 different theories spanning several disciplines. Respondents reported using theories primarily to identify implementation determinants, inform data collection, enhance conceptual clarity, and guide implementation planning. Of the 19 criteria presented in the survey, the criteria used by the most respondents to select theory included analytic level (58%), logical consistency/plausibility (56%), empirical support (53%), and description of a change process (54%). The criteria used by the fewest respondents included fecundity (10%), uniqueness (12%), and falsifiability (15%). Implementation scientists use a large number of criteria to select theories, but there is little consensus on which are most important. Our results suggest that the

  9. Population genetics inference for longitudinally-sampled mutants under strong selection.

    Science.gov (United States)

    Lacerda, Miguel; Seoighe, Cathal

    2014-11-01

    Longitudinal allele frequency data are becoming increasingly prevalent. Such samples permit statistical inference of the population genetics parameters that influence the fate of mutant variants. To infer these parameters by maximum likelihood, the mutant frequency is often assumed to evolve according to the Wright-Fisher model. For computational reasons, this discrete model is commonly approximated by a diffusion process that requires the assumption that the forces of natural selection and mutation are weak. This assumption is not always appropriate. For example, mutations that impart drug resistance in pathogens may evolve under strong selective pressure. Here, we present an alternative approximation to the mutant-frequency distribution that does not make any assumptions about the magnitude of selection or mutation and is much more computationally efficient than the standard diffusion approximation. Simulation studies are used to compare the performance of our method to that of the Wright-Fisher and Gaussian diffusion approximations. For large populations, our method is found to provide a much better approximation to the mutant-frequency distribution when selection is strong, while all three methods perform comparably when selection is weak. Importantly, maximum-likelihood estimates of the selection coefficient are severely attenuated when selection is strong under the two diffusion models, but not when our method is used. This is further demonstrated with an application to mutant-frequency data from an experimental study of bacteriophage evolution. We therefore recommend our method for estimating the selection coefficient when the effective population size is too large to utilize the discrete Wright-Fisher model. Copyright © 2014 by the Genetics Society of America.

  10. 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.

  11. Magnetically separable polymer (Mag-MIP) for selective analysis of biotin in food samples.

    Science.gov (United States)

    Uzuriaga-Sánchez, Rosario Josefina; Khan, Sabir; Wong, Ademar; Picasso, Gino; Pividori, Maria Isabel; Sotomayor, Maria Del Pilar Taboada

    2016-01-01

    This work presents an efficient method for the preparation of magnetic nanoparticles modified with molecularly imprinted polymers (Mag-MIP) through core-shell method for the determination of biotin in milk food samples. The functional monomer acrylic acid was selected from molecular modeling, EGDMA was used as cross-linking monomer and AIBN as radical initiator. The Mag-MIP and Mag-NIP were characterized by FTIR, magnetic hysteresis, XRD, SEM and N2-sorption measurements. The capacity of Mag-MIP for biotin adsorption, its kinetics and selectivity were studied in detail. The adsorption data was well described by Freundlich isotherm model with adsorption equilibrium constant (KF) of 1.46 mL g(-1). The selectivity experiments revealed that prepared Mag-MIP had higher selectivity toward biotin compared to other molecules with different chemical structure. The material was successfully applied for the determination of biotin in diverse milk samples using HPLC for quantification of the analyte, obtaining the mean value of 87.4% recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Forecasting Urban Air Quality via a Back-Propagation Neural Network and a Selection Sample Rule

    Directory of Open Access Journals (Sweden)

    Yonghong Liu

    2015-07-01

    Full Text Available In this paper, based on a sample selection rule and a Back Propagation (BP neural network, a new model of forecasting daily SO2, NO2, and PM10 concentration in seven sites of Guangzhou was developed using data from January 2006 to April 2012. A meteorological similarity principle was applied in the development of the sample selection rule. The key meteorological factors influencing SO2, NO2, and PM10 daily concentrations as well as weight matrices and threshold matrices were determined. A basic model was then developed based on the improved BP neural network. Improving the basic model, identification of the factor variation consistency was added in the rule, and seven sets of sensitivity experiments in one of the seven sites were conducted to obtain the selected model. A comparison of the basic model from May 2011 to April 2012 in one site showed that the selected model for PM10 displayed better forecasting performance, with Mean Absolute Percentage Error (MAPE values decreasing by 4% and R2 values increasing from 0.53 to 0.68. Evaluations conducted at the six other sites revealed a similar performance. On the whole, the analysis showed that the models presented here could provide local authorities with reliable and precise predictions and alarms about air quality if used at an operational scale.

  13. Development of ion imprinted polymers for the selective extraction of lanthanides from environmental samples

    International Nuclear Information System (INIS)

    Moussa, Manel

    2016-01-01

    The analysis of the lanthanide ions present at trace level in complex environmental matrices requires often a purification and preconcentration step. The solid phase extraction (SPE) is the most used sample preparation technique. To improve the selectivity of this step, Ion Imprinted Polymers (IIPs) can be used as SPE solid supports. The aim of this work was the development of IIPs for the selective extraction of lanthanide ions from environmental samples. In a first part, IIPs were prepared according to the trapping approach using 5,7-dichloroquinoline-8-ol as non-vinylated ligand. For the first time, the loss of the trapped ligand during template ion removal and sedimentation steps was demonstrated by HPLC-UV. Moreover, this loss was not repeatable, which led to a lack of repeatability of the SPE profiles. It was then demonstrated that the trapping approach is not appropriate for the IIPs synthesis. In a second part, IIPs were synthesized by chemical immobilization of methacrylic acid as vinylated monomer. The repeatability of the synthesis and the SPE protocol were confirmed. A good selectivity of the IIPs for all the lanthanide ions was obtained. IIPs were successfully used to selectively extract lanthanide ions from tap and river water. Finally, IIPs were synthesized by chemical immobilization of methacrylic acid and 4-vinylpyridine as functional monomers and either a light (Nd 3+ ) or a heavy (Er 3+ ) lanthanide ion as template. Both kinds of IIPs led to a similar selectivity for all lanthanide ions. Nevertheless, this selectivity can be modified by changing the nature and the pH of the washing solution used in the SPE protocol. (author)

  14. Selective parathyroid venous sampling in primary hyperparathyroidism: A systematic review and meta-analysis.

    Science.gov (United States)

    Ibraheem, Kareem; Toraih, Eman A; Haddad, Antoine B; Farag, Mahmoud; Randolph, Gregory W; Kandil, Emad

    2018-05-14

    Minimally invasive parathyroidectomy requires accurate preoperative localization techniques. There is considerable controversy about the effectiveness of selective parathyroid venous sampling (sPVS) in primary hyperparathyroidism (PHPT) patients. The aim of this meta-analysis is to examine the diagnostic accuracy of sPVS as a preoperative localization modality in PHPT. Studies evaluating the diagnostic accuracy of sPVS for PHPT were electronically searched in the PubMed, EMBASE, Web of Science, and Cochrane Controlled Trials Register databases. Two independent authors reviewed the studies, and revised quality assessment of diagnostic accuracy study tool was used for the quality assessment. Study heterogeneity and pooled estimates were calculated. Two hundred and two unique studies were identified. Of those, 12 studies were included in the meta-analysis. Pooled sensitivity, specificity, and positive likelihood ratio (PLR) of sPVS were 74%, 41%, and 1.55, respectively. The area-under-the-receiver operating characteristic curve was 0.684, indicating an average discriminatory ability of sPVS. On comparison between sPVS and noninvasive imaging modalities, sensitivity, PLR, and positive posttest probability were significantly higher in sPVS compared to noninvasive imaging modalities. Interestingly, super-selective venous sampling had the highest sensitivity, accuracy, and positive posttest probability compared to other parathyroid venous sampling techniques. This is the first meta-analysis to examine the accuracy of sPVS in PHPT. sPVS had higher pooled sensitivity when compared to noninvasive modalities in revision parathyroid surgery. However, the invasiveness of this technique does not favor its routine use for preoperative localization. Super-selective venous sampling was the most accurate among all other parathyroid venous sampling techniques. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

  15. [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.

  16. 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

  17. The Impact of Nutrition and Health Claims on Consumer Perceptions and Portion Size Selection: Results from a Nationally Representative Survey

    Science.gov (United States)

    Benson, Tony; Lavelle, Fiona; McCloat, Amanda; Mooney, Elaine; Egan, Bernadette; Collins, Clare E.; Dean, Moira

    2018-01-01

    Nutrition and health claims on foods can help consumers make healthier food choices. However, claims may have a ‘halo’ effect, influencing consumer perceptions of foods and increasing consumption. Evidence for these effects are typically demonstrated in experiments with small samples, limiting generalisability. The current study aimed to overcome this limitation through the use of a nationally representative survey. In a cross-sectional survey of 1039 adults across the island of Ireland, respondents were presented with three different claims (nutrition claim = “Low in fat”; health claim = “With plant sterols. Proven to lower cholesterol”; satiety claim = “Fuller for longer”) on four different foods (cereal, soup, lasagne, and yoghurt). Participants answered questions on perceived healthiness, tastiness, and fillingness of the products with different claims and also selected a portion size they would consume. Claims influenced fillingness perceptions of some of the foods. However, there was little influence of claims on tastiness or healthiness perceptions or the portion size selected. Psychological factors such as consumers’ familiarity with foods carrying claims and belief in the claims were the most consistent predictors of perceptions and portion size selection. Future research should identify additional consumer factors that may moderate the relationships between claims, perceptions, and consumption. PMID:29789472

  18. The Impact of Nutrition and Health Claims on Consumer Perceptions and Portion Size Selection: Results from a Nationally Representative Survey

    Directory of Open Access Journals (Sweden)

    Tony Benson

    2018-05-01

    Full Text Available Nutrition and health claims on foods can help consumers make healthier food choices. However, claims may have a ‘halo’ effect, influencing consumer perceptions of foods and increasing consumption. Evidence for these effects are typically demonstrated in experiments with small samples, limiting generalisability. The current study aimed to overcome this limitation through the use of a nationally representative survey. In a cross-sectional survey of 1039 adults across the island of Ireland, respondents were presented with three different claims (nutrition claim = “Low in fat”; health claim = “With plant sterols. Proven to lower cholesterol”; satiety claim = “Fuller for longer” on four different foods (cereal, soup, lasagne, and yoghurt. Participants answered questions on perceived healthiness, tastiness, and fillingness of the products with different claims and also selected a portion size they would consume. Claims influenced fillingness perceptions of some of the foods. However, there was little influence of claims on tastiness or healthiness perceptions or the portion size selected. Psychological factors such as consumers’ familiarity with foods carrying claims and belief in the claims were the most consistent predictors of perceptions and portion size selection. Future research should identify additional consumer factors that may moderate the relationships between claims, perceptions, and consumption.

  19. The diagnostic value of CT scan and selective venous sampling in Cushing's syndrome

    International Nuclear Information System (INIS)

    Negoro, Makoto; Kuwayama, Akio; Yamamoto, Naoto; Nakane, Toshichi; Yokoe, Toshio; Kageyama, Naoki; Ichihara, Kaoru; Ishiguchi, Tsuneo; Sakuma, Sadayuki

    1986-01-01

    We studied 24 patients with Cushing's syndrome in order to find the best way to confirm the pituitary adenoma preoperatively. At first, the sellar content was studied by means of a high-resolution CT scan in each patient. Second, by selective catheterization in the bilateral internal jugular vein and the inferior petrosal sinus, venous samples (c) were obtained for ACTH assay. Simultaneously, peripheral blood sampling (P) was made at the anterior cubital vein for the same purpose, and the C/P ratio was carefully calculated in each patient. If the C/P ratio exceeded 2, it was highly suggestive of the presence of pituitary adenoma. Even by an advanced high-resolution CT scan with a thickness of 2 mm, pituitary adenomas were detected in only 32 % of the patients studied. The result of image diagnosis in Cushing disease was discouraging. As for the chemical diagnosis, the results were as follows. At the early stage of this study, the catheterization was terminated in the jugular veins of nine patients. Among these, in five patients the presence of pituitary adenoma was predicted correctly in the preoperative stage. Later, by means of inferior petrosal sinus samplings, pituitary microadenomas were detected in ten patients among the twelve. Selective venous sampling for ACTH in the inferior petrosal sinus or jugular vein proved to be useful for the differential diagnosis of Cushing's syndrome when other diagnostic measures such as CT scan were inconclusive. (author)

  20. Novel joint selection methods can reduce sample size for rheumatoid arthritis clinical trials with ultrasound endpoints.

    Science.gov (United States)

    Allen, John C; Thumboo, Julian; Lye, Weng Kit; Conaghan, Philip G; Chew, Li-Ching; Tan, York Kiat

    2018-03-01

    To determine whether novel methods of selecting joints through (i) ultrasonography (individualized-ultrasound [IUS] method), or (ii) ultrasonography and clinical examination (individualized-composite-ultrasound [ICUS] method) translate into smaller rheumatoid arthritis (RA) clinical trial sample sizes when compared to existing methods utilizing predetermined joint sites for ultrasonography. Cohen's effect size (ES) was estimated (ES^) and a 95% CI (ES^L, ES^U) calculated on a mean change in 3-month total inflammatory score for each method. Corresponding 95% CIs [nL(ES^U), nU(ES^L)] were obtained on a post hoc sample size reflecting the uncertainty in ES^. Sample size calculations were based on a one-sample t-test as the patient numbers needed to provide 80% power at α = 0.05 to reject a null hypothesis H 0 : ES = 0 versus alternative hypotheses H 1 : ES = ES^, ES = ES^L and ES = ES^U. We aimed to provide point and interval estimates on projected sample sizes for future studies reflecting the uncertainty in our study ES^S. Twenty-four treated RA patients were followed up for 3 months. Utilizing the 12-joint approach and existing methods, the post hoc sample size (95% CI) was 22 (10-245). Corresponding sample sizes using ICUS and IUS were 11 (7-40) and 11 (6-38), respectively. Utilizing a seven-joint approach, the corresponding sample sizes using ICUS and IUS methods were nine (6-24) and 11 (6-35), respectively. Our pilot study suggests that sample size for RA clinical trials with ultrasound endpoints may be reduced using the novel methods, providing justification for larger studies to confirm these observations. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

  1. Stability of selected volatile breath constituents in Tedlar, Kynar and Flexfilm sampling bags

    Science.gov (United States)

    Mochalski, Paweł; King, Julian; Unterkofler, Karl; Amann, Anton

    2016-01-01

    The stability of 41 selected breath constituents in three types of polymer sampling bags, Tedlar, Kynar, and Flexfilm, was investigated using solid phase microextraction and gas chromatography mass spectrometry. The tested molecular species belong to different chemical classes (hydrocarbons, ketones, aldehydes, aromatics, sulphurs, esters, terpenes, etc.) and exhibit close-to-breath low ppb levels (3–12 ppb) with the exception of isoprene, acetone and acetonitrile (106 ppb, 760 ppb, 42 ppb respectively). Stability tests comprised the background emission of contaminants, recovery from dry samples, recovery from humid samples (RH 80% at 37 °C), influence of the bag’s filling degree, and reusability. Findings yield evidence of the superiority of Tedlar bags over remaining polymers in terms of background emission, species stability (up to 7 days for dry samples), and reusability. Recoveries of species under study suffered from the presence of high amounts of water (losses up to 10%). However, only heavier volatiles, with molecular masses higher than 90, exhibited more pronounced losses (20–40%). The sample size (the degree of bag filling) was found to be one of the most important factors affecting the sample integrity. To sum up, it is recommended to store breath samples in pre-conditioned Tedlar bags up to 6 hours at the maximum possible filling volume. Among the remaining films, Kynar can be considered as an alternative to Tedlar; however, higher losses of compounds should be expected even within the first hours of storage. Due to the high background emission Flexfilm is not suitable for sampling and storage of samples for analyses aiming at volatiles at a low ppb level. PMID:23323261

  2. Size selective isocyanate aerosols personal air sampling using porous plastic foams

    International Nuclear Information System (INIS)

    Cong Khanh Huynh; Trinh Vu Duc

    2009-01-01

    As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

  3. A Principle Component Analysis of Galaxy Properties from a Large, Gas-Selected Sample

    Directory of Open Access Journals (Sweden)

    Yu-Yen Chang

    2012-01-01

    concluded that this is in conflict with the CDM model. Considering the importance of the issue, we reinvestigate the problem using the principal component analysis on a fivefold larger sample and additional near-infrared data. We use databases from the Arecibo Legacy Fast Arecibo L-band Feed Array Survey for the gas properties, the Sloan Digital Sky Survey for the optical properties, and the Two Micron All Sky Survey for the near-infrared properties. We confirm that the parameters are indeed correlated where a single physical parameter can explain 83% of the variations. When color (g-i is included, the first component still dominates but it develops a second principal component. In addition, the near-infrared color (i-J shows an obvious second principal component that might provide evidence of the complex old star formation. Based on our data, we suggest that it is premature to pronounce the failure of the CDM model and it motivates more theoretical work.

  4. Bulgeless galaxies at intermediate redshift: Sample selection, color properties, and the existence of powerful active galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bizzocchi, Luca; Leonardo, Elvira; Grossi, Marco; Afonso, José; Fernandes, Cristina; Retrê, João [Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisbon (Portugal); Filho, Mercedes E.; Lobo, Catarina [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Griffith, Roger L. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Anton, Sonia [Centro de Investigação em Ciências Geo-Espaciais, Faculdade de Ciências da Universidade do Porto, Porto (Portugal); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Brinchmann, Jarle [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Henriques, Bruno [Max-Planck-Institut für Astrophysik, Karl Schwarzschild Straße 1, D-85748 Garching bei München (Germany); Messias, Hugo [Departamento de astronomía, Av. Esteban Iturra 6to piso, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción (Chile)

    2014-02-10

    We present a catalog of bulgeless galaxies, which includes 19,225 objects selected in four of the deepest, largest multi-wavelength data sets available—COSMOS, AEGIS, GEMS, and GOODS—at intermediate redshift (0.4 ≤ z ≤ 1.0). The morphological classification was provided by the Advanced Camera for Surveys General Catalog (ACS-GC), which used publicly available data obtained with the ACS instrument on the Hubble Space Telescope. Rest-frame photometric quantities were derived using kcorrect. We analyze the properties of the sample and the evolution of pure-disk systems with redshift. Very massive [log (M {sub *}/M {sub ☉}) > 10.5] bulgeless galaxies contribute to ∼30% of the total galaxy population number density at z ≥ 0.7, but their number density drops substantially with decreasing redshift. We show that only a negligible fraction of pure disks appear to be quiescent systems, and red sequence bulgeless galaxies show indications of dust-obscured star formation. X-ray catalogs were used to search for X-ray emission within our sample. After visual inspection and detailed parametric morphological fitting we identify 30 active galactic nuclei (AGNs) that reside in galaxies without a classical bulge. The finding of such peculiar objects at intermediate redshift shows that while AGN growth in merger-free systems is a rare event (0.2% AGN hosts in this sample of bulgeless galaxies), it can indeed happen relatively early in the history of the universe.

  5. Accretion Properties of a Sample of Hard X-Ray (<60 keV) Selected Seyfert 1 Galaxies

    Science.gov (United States)

    Wang, J.; Mao, Y. F.; Wei, J. Y.

    2009-02-01

    We examine the accretion properties in a sample of 42 hard (3-60 keV) X-ray selected nearby broad-line active galactic nuclei (AGNs). The energy range in the sample is harder than that usually used in similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey, and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad Hβ emission line. The tight correlation between the hard X-ray (3-20 keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the Hβ emission line. In addition, all of these hard X-ray AGNs are biased toward luminous objects with a high Eddington ratio (mostly between 0.01 and 0.1) and a low column density (Simbol-X, and NeXT. Finally, the correlation between RFe (= optical Fe II/Hβ) and disk temperature as assessed by T vprop (L/L Edd)M -1 BH leads us to suggest that the strength of the Fe II emission is mainly determined by the shape of the ionizing spectrum.

  6. An Aerial Radiological Survey of Selected Areas of Area 18 - Nevada Test Site

    International Nuclear Information System (INIS)

    Lyons, Craig

    2009-01-01

    As part of the proficiency training for the Radiological Mapping mission of the Aerial Measuring System (AMS), a survey team from the Remote Sensing Laboratory-Nellis (RSL-Nellis) conducted an aerial radiological survey of selected areas of Area 18 of the Nevada Test Site (NTS) for the purpose of mapping man-made radiation deposited as a result of the Johnnie Boy and Little Feller I tests. The survey area centered over the Johnnie Boy ground zero but also included the ground zero and deposition area of the Little Feller I test, approximately 7,000 feet (2133 meters) southeast of the Johnnie Boy site. The survey was conducted in one flight. The completed survey covered a total of 4.0 square miles. The flight lines (with the turns) over the surveyed areas are presented in Figure 1. One 2.5-hour-long flight was performed at an altitude of 100 ft above ground level (AGL) with 200 foot flight-line spacing. A test-line flight was conducted near the Desert Rock Airstrip to ensure quality control of the data. The test line is not shown in Figure 1. However, Figure 1 does include the flight lines for a ''perimeter'' flight. The path traced by the helicopter flying over distinct roads within the survey area can be used to overlay the survey data on a base map or image. The flight survey lines were flown in an east-west orientation perpendicular to the deposition patterns for both sites. This technique provides better spatial resolution when contouring the data. The data were collected by the AMS data acquisition system (REDAR V) using an array of twelve 2-inch x 4-inch x 16-inch sodium iodide (NaI) detectors flown on-board a twin-engine Bell 412 helicopter. Data, in the form of gamma energy spectra, were collected every second over the course of the survey and were geo-referenced using a differential Global Positioning System. Spectral data allows the system to distinguish between ordinary fluctuations in natural background radiation levels and the signature produced by man

  7. Antibiotic content of selective culture media for isolation of Capnocytophaga species from oral polymicrobial samples.

    Science.gov (United States)

    Ehrmann, E; Jolivet-Gougeon, A; Bonnaure-Mallet, M; Fosse, T

    2013-10-01

    In oral microbiome, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of fastidious Capnocytophaga species. The performances of six culture media (blood agar, chocolate blood agar, VCAT medium, CAPE medium, bacitracin chocolate blood agar and VK medium) were compared with literature data concerning five other media (FAA, LB, TSBV, CapR and TBBP media). To understand variable growth on selective media, the MICs of each antimicrobial agent contained in this different media (colistin, kanamycin, trimethoprim, trimethoprim-sulfamethoxazole, vancomycin, aztreonam and bacitracin) were determined for all Capnocytophaga species. Overall, VCAT medium (Columbia, 10% cooked horse blood, polyvitaminic supplement, 3·75 mg l(-1) of colistin, 1·5 mg l(-1) of trimethoprim, 1 mg l(-1) of vancomycin and 0·5 mg l(-1) of amphotericin B, Oxoid, France) was the more efficient selective medium, with regard to the detection of Capnocytophaga species from oral samples (P culture, a simple blood agar allowed the growth of all Capnocytophaga species. Nonetheless, in oral samples, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of Capnocytophaga species. The demonstrated superiority of VCAT medium made its use essential for the optimal detection of this bacterial genus. This work showed that extreme caution should be exercised when reporting the isolation of Capnocytophaga species from oral polymicrobial samples, because the culture medium is a determining factor. © 2013 The Society for Applied Microbiology.

  8. New journal selection for quantitative survey of infectious disease research: application for Asian trend analysis

    Directory of Open Access Journals (Sweden)

    Okabe Nobuhiko

    2009-10-01

    Full Text Available Abstract Background Quantitative survey of research articles, as an application of bibliometrics, is an effective tool for grasping overall trends in various medical research fields. This type of survey has been also applied to infectious disease research; however, previous studies were insufficient as they underestimated articles published in non-English or regional journals. Methods Using a combination of Scopus™ and PubMed, the databases of scientific literature, and English and non-English keywords directly linked to infectious disease control, we identified international and regional infectious disease journals. In order to ascertain whether the newly selected journals were appropriate to survey a wide range of research articles, we compared the number of original articles and reviews registered in the selected journals to those in the 'Infectious Disease Category' of the Science Citation Index Expanded™ (SCI Infectious Disease Category during 1998-2006. Subsequently, we applied the newly selected journals to survey the number of original articles and reviews originating from 11 Asian countries during the same period. Results One hundred journals, written in English or 7 non-English languages, were newly selected as infectious disease journals. The journals published 14,156 original articles and reviews of Asian origin and 118,158 throughout the world, more than those registered in the SCI Infectious Disease Category (4,621 of Asian origin and 66,518 of the world in the category. In Asian trend analysis of the 100 journals, Japan had the highest percentage of original articles and reviews in the area, and no noticeable increase in articles was revealed during the study period. China, India and Taiwan had relatively large numbers and a high increase rate of original articles among Asian countries. When adjusting the publication of original articles according to the country population and the gross domestic product (GDP, Singapore and

  9. Ground-survey and water-quality data for selected wetlands on or near the Lower Brule Indian Reservation in South Dakota, 2012-13

    Science.gov (United States)

    Neitzert, Kathleen M.; Thompson, Ryan F.

    2015-08-20

    Numerous lakes, ponds, and wetlands are located within the Lower Brule Indian Reservation. Wetlands are an important resource providing aquatic habitat for plants and animals, and acting as a natural water filtration system. Several of the wetlands on or near the reservation are of particular interest, but information on the physical and biological integrity of these wetlands was needed to provide a base-line reference when planning for future water management needs. A reconnaissance-level study of selected wetlands on and near the Lower Brule Indian Reservation was completed in 2012–13 by the U.S. Geological Survey in cooperation with the Lower Brule Sioux Tribe using ground surveys and water-quality analyses. Ground surveys of six wetland areas (Dorman Slough, Little Bend Wetlands, Miller Pond, Potter Slough, an unnamed slough, and West Brule Community wetlands) were completed to map land, water, vegetation, and man-made features of the selected wetland areas using real-time kinematic global navigation satellite systems equipment. Water samples were collected from four of the selected wetlands. Two separate waterbodies were sampled at one of the wetlands for a total of five sampling locations. Water samples were analyzed for physical properties, selected inorganics, metals, nutrients, and suspended sediment. Concentrations of calcium, sodium, and sulfate were greater at the two wetland sites fed by ground water, compared to the wetland sites fed by surface runoff.

  10. Could hypomanic traits explain selective migration? Verifying the hypothesis by the surveys on sardinian migrants.

    Science.gov (United States)

    Giovanni, Carta Mauro; Francesca, Moro Maria; Viviane, Kovess; Brasesco, Maria Veronica; Bhat, Krishna M; Matthias, Angermeyer C; Akiskal, Hagop S

    2012-01-01

    A recent survey put forward the hypothesis that the emigration that occurred from Sardinia from the 1960's to the 1980's, selected people with a hypomanic temperament. The paper aims to verify if the people who migrated from Sardinia in that period have shown a high risk of mood disorders in the surveys carried out in their host countries, and if the results are consistent with this hypothesis. This is systematic review. In the 1970's when examining the attitudes towards migration in Sardinian couples waiting to emigrate, Rudas found that the decision to emigrate was principally taken by males. Female showed lower self-esteem than male emigrants. A study on Sardinian immigrants in Argentina carried out in 2001-02, at the peak of the economic crisis, found a high risk of depressive disorders in women only. These results were opposite to the findings recorded ten years earlier in a survey on Sardinian immigrants in Paris, where the risk of Depressive Episode was higher in young men only. Data point to a bipolar disorder risk for young (probably hypomanic) male migrants in competitive, challenging conditions; and a different kind of depressive episodes for women in trying economic conditions. The results of the survey on Sardinian migrants are partially in agreement with the hypothesis of a selective migration of people with a hypomanic temperament. Early motivations and self-esteem seem related to the ways mood disorders are expressed, and to the vulnerability to specific triggering situations in the host country.

  11. 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

  12. A novel variable selection approach that iteratively optimizes variable space using weighted binary matrix sampling.

    Science.gov (United States)

    Deng, Bai-chuan; Yun, Yong-huan; Liang, Yi-zeng; Yi, Lun-zhao

    2014-10-07

    In this study, a new optimization algorithm called the Variable Iterative Space Shrinkage Approach (VISSA) that is based on the idea of model population analysis (MPA) is proposed for variable selection. Unlike most of the existing optimization methods for variable selection, VISSA statistically evaluates the performance of variable space in each step of optimization. Weighted binary matrix sampling (WBMS) is proposed to generate sub-models that span the variable subspace. Two rules are highlighted during the optimization procedure. First, the variable space shrinks in each step. Second, the new variable space outperforms the previous one. The second rule, which is rarely satisfied in most of the existing methods, is the core of the VISSA strategy. Compared with some promising variable selection methods such as competitive adaptive reweighted sampling (CARS), Monte Carlo uninformative variable elimination (MCUVE) and iteratively retaining informative variables (IRIV), VISSA showed better prediction ability for the calibration of NIR data. In addition, VISSA is user-friendly; only a few insensitive parameters are needed, and the program terminates automatically without any additional conditions. The Matlab codes for implementing VISSA are freely available on the website: https://sourceforge.net/projects/multivariateanalysis/files/VISSA/.

  13. Selection of Sampling Pumps Used for Groundwater Monitoring at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Schalla, Ronald; Webber, William D.; Smith, Ronald M.

    2001-11-05

    The variable frequency drive centrifugal submersible pump, Redi-Flo2a made by Grundfosa, was selected for universal application for Hanford Site groundwater monitoring. Specifications for the selected pump and five other pumps were evaluated against current and future Hanford groundwater monitoring performance requirements, and the Redi-Flo2 was selected as the most versatile and applicable for the range of monitoring conditions. The Redi-Flo2 pump distinguished itself from the other pumps considered because of its wide range in output flow rate and its comparatively moderate maintenance and low capital costs. The Redi-Flo2 pump is able to purge a well at a high flow rate and then supply water for sampling at a low flow rate. Groundwater sampling using a low-volume-purging technique (e.g., low flow, minimal purge, no purge, or micropurgea) is planned in the future, eliminating the need for the pump to supply a high-output flow rate. Under those conditions, the Well Wizard bladder pump, manufactured by QED Environmental Systems, Inc., may be the preferred pump because of the lower capital cost.

  14. Concurrent and Longitudinal Associations Among Temperament, Parental Feeding Styles, and Selective Eating in a Preschool Sample.

    Science.gov (United States)

    Kidwell, Katherine M; Kozikowski, Chelsea; Roth, Taylor; Lundahl, Alyssa; Nelson, Timothy D

    2018-06-01

    To examine the associations among negative/reactive temperament, feeding styles, and selective eating in a sample of preschoolers because preschool eating behaviors likely have lasting implications for children's health. A community sample of preschoolers aged 3-5 years (M = 4.49 years, 49.5% female, 75.7% European American) in the Midwest of the United States was recruited to participate in the study (N = 297). Parents completed measures of temperament and feeding styles at two time points 6 months apart. A series of regressions indicated that children who had temperaments high in negative affectivity were significantly more likely to experience instrumental and emotional feeding styles. They were also significantly more likely to be selective eaters. These associations were present when examined both concurrently and after 6 months. This study provides a novel investigation of child temperament and eating behaviors, allowing for a better understanding of how negative affectivity is associated with instrumental feeding, emotional feeding, and selective eating. These results inform interventions to improve child health.

  15. LOCAL BENCHMARKS FOR THE EVOLUTION OF MAJOR-MERGER GALAXIES-SPITZER OBSERVATIONS OF A K-BAND SELECTED SAMPLE

    International Nuclear Information System (INIS)

    Xu, C. Kevin; Cheng Yiwen; Lu Nanyao; Mazzarella, Joseph M.; Cutri, Roc; Domingue, Donovan; Huang Jiasheng; Gao Yu; Sun, W.-H.; Surace, Jason

    2010-01-01

    We present Spitzer observations for a sample of close major-merger galaxy pairs (KPAIR sample) selected from cross-matches between the Two Micron All Sky Survey and Sloan Digital Sky Survey Data Release 3. The goals are to study the star formation activity in these galaxies and to set a local bench mark for the cosmic evolution of close major mergers. The Spitzer KPAIR sample (27 pairs, 54 galaxies) includes all spectroscopically confirmed spiral-spiral (S+S) and spiral-elliptical (S+E) pairs in a parent sample that is complete for primaries brighter than K = 12.5 mag, projected separations of 5 h -1 kpc ≤ s ≤ 20 h -1 kpc, and mass ratios ≤2.5. The Spitzer data, consisting of images in seven bands (3.6, 4.5, 5.8, 8, 24, 70, 160 μm), show very diversified IR emission properties. Compared to single spiral galaxies in a control sample, only spiral galaxies in S+S pairs show significantly enhanced specific star formation rate (sSFR = SFR/M), whereas spiral galaxies in S+E pairs do not. Furthermore, the SFR enhancement of spiral galaxies in S+S pairs is highly mass-dependent. Only those with M ∼> 10 10.5 M sun show significant enhancement. Relatively low-mass (M ∼ 10 10 M sun ) spirals in S+S pairs have about the same SFR/M compared to their counterparts in the control sample, while those with 10 11 M sun have on average a ∼3 times higher SFR/M than single spirals. There is evidence for a correlation between the global star formation activities (but not the nuclear activities) of the component galaxies in massive S+S major-merger pairs (the H olmberg effect ) . There is no significant difference in the SFR/M between the primaries and the secondaries, nor between spirals of SEP KPAIR =2.54 x 10 -4 (M sun yr -1 Mpc -3 ).

  16. Frequency-Wavenumber (FK)-Based Data Selection in High-Frequency Passive Surface Wave Survey

    Science.gov (United States)

    Cheng, Feng; Xia, Jianghai; Xu, Zongbo; Hu, Yue; Mi, Binbin

    2018-04-01

    Passive surface wave methods have gained much attention from geophysical and civil engineering communities because of the limited application of traditional seismic surveys in highly populated urban areas. Considering that they can provide high-frequency phase velocity information up to several tens of Hz, the active surface wave survey would be omitted and the amount of field work could be dramatically reduced. However, the measured dispersion energy image in the passive surface wave survey would usually be polluted by a type of "crossed" artifacts at high frequencies. It is common in the bidirectional noise distribution case with a linear receiver array deployed along roads or railways. We review several frequently used passive surface wave methods and derive the underlying physics for the existence of the "crossed" artifacts. We prove that the "crossed" artifacts would cross the true surface wave energy at fixed points in the f-v domain and propose a FK-based data selection technique to attenuate the artifacts in order to retrieve the high-frequency information. Numerical tests further demonstrate the existence of the "crossed" artifacts and indicate that the well-known wave field separation method, FK filter, does not work for the selection of directional noise data. Real-world applications manifest the feasibility of the proposed FK-based technique to improve passive surface wave methods by a priori data selection. Finally, we discuss the applicability of our approach.

  17. Frequency-Wavenumber (FK)-Based Data Selection in High-Frequency Passive Surface Wave Survey

    Science.gov (United States)

    Cheng, Feng; Xia, Jianghai; Xu, Zongbo; Hu, Yue; Mi, Binbin

    2018-07-01

    Passive surface wave methods have gained much attention from geophysical and civil engineering communities because of the limited application of traditional seismic surveys in highly populated urban areas. Considering that they can provide high-frequency phase velocity information up to several tens of Hz, the active surface wave survey would be omitted and the amount of field work could be dramatically reduced. However, the measured dispersion energy image in the passive surface wave survey would usually be polluted by a type of "crossed" artifacts at high frequencies. It is common in the bidirectional noise distribution case with a linear receiver array deployed along roads or railways. We review several frequently used passive surface wave methods and derive the underlying physics for the existence of the "crossed" artifacts. We prove that the "crossed" artifacts would cross the true surface wave energy at fixed points in the f- v domain and propose a FK-based data selection technique to attenuate the artifacts in order to retrieve the high-frequency information. Numerical tests further demonstrate the existence of the "crossed" artifacts and indicate that the well-known wave field separation method, FK filter, does not work for the selection of directional noise data. Real-world applications manifest the feasibility of the proposed FK-based technique to improve passive surface wave methods by a priori data selection. Finally, we discuss the applicability of our approach.

  18. 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.

  19. Correlations Between Life-Detection Techniques and Implications for Sampling Site Selection in Planetary Analog Missions

    Science.gov (United States)

    Gentry, Diana M.; Amador, Elena S.; Cable, Morgan L.; Chaudry, Nosheen; Cullen, Thomas; Jacobsen, Malene B.; Murukesan, Gayathri; Schwieterman, Edward W.; Stevens, Adam H.; Stockton, Amanda; Tan, George; Yin, Chang; Cullen, David C.; Geppert, Wolf

    2017-10-01

    We conducted an analog sampling expedition under simulated mission constraints to areas dominated by basaltic tephra of the Eldfell and Fimmvörðuháls lava fields (Iceland). Sites were selected to be "homogeneous" at a coarse remote sensing resolution (10-100 m) in apparent color, morphology, moisture, and grain size, with best-effort realism in numbers of locations and replicates. Three different biomarker assays (counting of nucleic-acid-stained cells via fluorescent microscopy, a luciferin/luciferase assay for adenosine triphosphate, and quantitative polymerase chain reaction (qPCR) to detect DNA associated with bacteria, archaea, and fungi) were characterized at four nested spatial scales (1 m, 10 m, 100 m, and >1 km) by using five common metrics for sample site representativeness (sample mean variance, group F tests, pairwise t tests, and the distribution-free rank sum H and u tests). Correlations between all assays were characterized with Spearman's rank test. The bioluminescence assay showed the most variance across the sites, followed by qPCR for bacterial and archaeal DNA; these results could not be considered representative at the finest resolution tested (1 m). Cell concentration and fungal DNA also had significant local variation, but they were homogeneous over scales of >1 km. These results show that the selection of life detection assays and the number, distribution, and location of sampling sites in a low biomass environment with limited a priori characterization can yield both contrasting and complementary results, and that their interdependence must be given due consideration to maximize science return in future biomarker sampling expeditions.

  20. Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Kim, Pil-Gon; Roh, Ji-Yeon; Hong, Yongseok; Kwon, Jung-Hwan

    2017-10-01

    Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K sampler/soil ) and the uptake rate constant (k u ) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K sampler/soil and k u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K sampler/soil and k u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 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.

  2. 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.

  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. Composition of Trace Metals in Dust Samples Collected from Selected High Schools in Pretoria, South Africa

    Directory of Open Access Journals (Sweden)

    J. O. Olowoyo

    2016-01-01

    Full Text Available Potential health risks associated with trace metal pollution have necessitated the importance of monitoring their levels in the environment. The present study investigated the concentrations and compositions of trace metals in dust samples collected from classrooms and playing ground from the selected high schools In Pretoria. Schools were selected from Pretoria based on factors such as proximity to high traffic ways, industrial areas, and residential areas. Thirty-two dust samples were collected from inside and outside the classrooms, where learners often stay during recess period. The dust samples were analysed for trace metal concentrations using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS. The composition of the elements showed that the concentrations of Zn were more than all other elements except from one of the schools. There were significant differences in the concentrations of trace metals from the schools (p<0.05. Regular cleaning, proximity to busy road, and well maintained gardens seem to have positive effects on the concentrations of trace metals recorded from the classrooms dust. The result further revealed a positive correlation for elements such as Pb, Cu, Zn, Mn, and Sb, indicating that the dust might have a common source.

  5. Detection of Salmonella spp. in veterinary samples by combining selective enrichment and real-time PCR.

    Science.gov (United States)

    Goodman, Laura B; McDonough, Patrick L; Anderson, Renee R; Franklin-Guild, Rebecca J; Ryan, James R; Perkins, Gillian A; Thachil, Anil J; Glaser, Amy L; Thompson, Belinda S

    2017-11-01

    Rapid screening for enteric bacterial pathogens in clinical environments is essential for biosecurity. Salmonella found in veterinary hospitals, particularly Salmonella enterica serovar Dublin, can pose unique challenges for culture and testing because of its poor growth. Multiple Salmonella serovars including Dublin are emerging threats to public health given increasing prevalence and antimicrobial resistance. We adapted an automated food testing method to veterinary samples and evaluated the performance of the method in a variety of matrices including environmental samples ( n = 81), tissues ( n = 52), feces ( n = 148), and feed ( n = 29). A commercial kit was chosen as the basis for this approach in view of extensive performance characterizations published by multiple independent organizations. A workflow was established for efficiently and accurately testing veterinary matrices and environmental samples by use of real-time PCR after selective enrichment in Rappaport-Vassiliadis soya (RVS) medium. Using this method, the detection limit for S. Dublin improved by 100-fold over subculture on selective agars (eosin-methylene blue, brilliant green, and xylose-lysine-deoxycholate). Overall, the procedure was effective in detecting Salmonella spp. and provided next-day results.

  6. Selective removal of phosphate for analysis of organic acids in complex samples.

    Science.gov (United States)

    Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

    2015-04-03

    Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Acrylamide exposure among Turkish toddlers from selected cereal-based baby food samples.

    Science.gov (United States)

    Cengiz, Mehmet Fatih; Gündüz, Cennet Pelin Boyacı

    2013-10-01

    In this study, acrylamide exposure from selected cereal-based baby food samples was investigated among toddlers aged 1-3 years in Turkey. The study contained three steps. The first step was collecting food consumption data and toddlers' physical properties, such as gender, age and body weight, using a questionnaire given to parents by a trained interviewer between January and March 2012. The second step was determining the acrylamide levels in food samples that were reported on by the parents in the questionnaire, using a gas chromatography-mass spectrometry (GC-MS) method. The last step was combining the determined acrylamide levels in selected food samples with individual food consumption and body weight data using a deterministic approach to estimate the acrylamide exposure levels. The mean acrylamide levels of baby biscuits, breads, baby bread-rusks, crackers, biscuits, breakfast cereals and powdered cereal-based baby foods were 153, 225, 121, 604, 495, 290 and 36 μg/kg, respectively. The minimum, mean and maximum acrylamide exposures were estimated to be 0.06, 1.43 and 6.41 μg/kg BW per day, respectively. The foods that contributed to acrylamide exposure were aligned from high to low as bread, crackers, biscuits, baby biscuits, powdered cereal-based baby foods, baby bread-rusks and breakfast cereals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. 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

  9. Polymer platforms for selective detection of cocaine in street samples adulterated with levamisole.

    Science.gov (United States)

    Florea, Anca; Cowen, Todd; Piletsky, Sergey; De Wael, Karolien

    2018-08-15

    Accurate drug detection is of utmost importance for fighting against drug abuse. With a high number of cutting agents and adulterants being added to cut or mask drugs in street powders the number of false results is increasing. We demonstrate for the first time the usefulness of employing polymers readily synthesized by electrodeposition to selectively detect cocaine in the presence of the commonly used adulterant levamisole. The polymers were selected by computational modelling to exhibit high binding affinity towards cocaine and deposited directly on the surface of graphene-modified electrodes via electropolymerization. The resulting platforms allowed a distinct electrochemical signal for cocaine, which is otherwise suppressed by levamisole. Square wave voltammetry was used to quantify cocaine alone and in the presence of levamisole. The usefulness of the platforms was demonstrated in the screening of real street samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Rapid determination of trace level copper in tea infusion samples by solid contact ion selective electrode

    Directory of Open Access Journals (Sweden)

    Aysenur Birinci

    2016-07-01

    Full Text Available A new solid contact copper selective electrode with a poly (vinyl chloride (PVC membrane consisting of o-xylylenebis(N,N-diisobutyldithiocarbamate as ionophore has been prepared. The main novelties of constructed ion selective electrode concept are the enhanced robustness, cheapness, and fastness due to the use of solid contacts. The electrode exhibits a rapid (< 10 seconds and near-Nernstian response to Cu2+ activity from 10−1 to 10−6 mol/L at the pH range of 4.0–6.0. No serious interference from common ions was found. The electrode characterizes by high potential stability, reproducibility, and full repeatability. The electrode was used as an indicator electrode in potentiometric titration of Cu(II ions with EDTA and for the direct assay of tea infusion samples by means of the calibration graph technique. The results compared favorably with those obtained by the atomic absorption spectroscopy (AAS.

  11. Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. isolated from chicken samples.

    Science.gov (United States)

    Er, Buket; Demirhan, Burak; Onurdag, Fatma Kaynak; Ozgacar, Selda Özgen; Oktem, Aysel Bayhan

    2014-03-01

    Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food

  12. Pesticides, selected elements, and other chemicals in adult total diet samples October 1979-September 1980

    International Nuclear Information System (INIS)

    Gartrell, M.J.; Craun, J.C.; Podrebarac, D.S.; Gunderson, E.L.

    1985-01-01

    The US Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for adult Total Diet samples collected in 20 cities between October 1979 and September 1980. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and are within acceptable limits. The results for samples collected during the same period that represent the diets of infants and toddlers are reported separately

  13. A genetic algorithm-based framework for wavelength selection on sample categorization.

    Science.gov (United States)

    Anzanello, Michel J; Yamashita, Gabrielli; Marcelo, Marcelo; Fogliatto, Flávio S; Ortiz, Rafael S; Mariotti, Kristiane; Ferrão, Marco F

    2017-08-01

    In forensic and pharmaceutical scenarios, the application of chemometrics and optimization techniques has unveiled common and peculiar features of seized medicine and drug samples, helping investigative forces to track illegal operations. This paper proposes a novel framework aimed at identifying relevant subsets of attenuated total reflectance Fourier transform infrared (ATR-FTIR) wavelengths for classifying samples into two classes, for example authentic or forged categories in case of medicines, or salt or base form in cocaine analysis. In the first step of the framework, the ATR-FTIR spectra were partitioned into equidistant intervals and the k-nearest neighbour (KNN) classification technique was applied to each interval to insert samples into proper classes. In the next step, selected intervals were refined through the genetic algorithm (GA) by identifying a limited number of wavelengths from the intervals previously selected aimed at maximizing classification accuracy. When applied to Cialis®, Viagra®, and cocaine ATR-FTIR datasets, the proposed method substantially decreased the number of wavelengths needed to categorize, and increased the classification accuracy. From a practical perspective, the proposed method provides investigative forces with valuable information towards monitoring illegal production of drugs and medicines. In addition, focusing on a reduced subset of wavelengths allows the development of portable devices capable of testing the authenticity of samples during police checking events, avoiding the need for later laboratorial analyses and reducing equipment expenses. Theoretically, the proposed GA-based approach yields more refined solutions than the current methods relying on interval approaches, which tend to insert irrelevant wavelengths in the retained intervals. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. The Important Selection Criteria in Choosing Islamic Banks: A Survey in Bahrain

    Directory of Open Access Journals (Sweden)

    Abdullah Hamzah Al-Hadrami

    2017-05-01

    Full Text Available Selection criteria of banks in general and Islamic banks in particular have been given high attention by the marketing researchers nowadays. But this kind of research is still insufficient in numbers especially in the developing countries. Therefore, this study aims to identify the important selection criteria that are considered by customers in selecting Islamic banks in the Kingdom of Bahrain. A 5-Likert scale survey questionnaire and ANOVA were used as the research method. The results indicate that the religious factors were ranked as the most important selection criteria for selecting Islamic banks. The study also found service quality factors as the second important selection criteria. This study is expected to provide Islamic banks in Bahrain with some inputs in setting up their marketing strategies in order to attract new customers and retain their existing customers. This study is also expected to add value to the literature by providing the updated empirical study in the area. DOI: 10.15408/aiq9i2.4635

  15. Cold Spray Deposition of Freestanding Inconel Samples and Comparative Analysis with Selective Laser Melting

    Science.gov (United States)

    Bagherifard, Sara; Roscioli, Gianluca; Zuccoli, Maria Vittoria; Hadi, Mehdi; D'Elia, Gaetano; Demir, Ali Gökhan; Previtali, Barbara; Kondás, Ján; Guagliano, Mario

    2017-10-01

    Cold spray offers the possibility of obtaining almost zero-porosity buildups with no theoretical limit to the thickness. Moreover, cold spray can eliminate particle melting, evaporation, crystallization, grain growth, unwanted oxidation, undesirable phases and thermally induced tensile residual stresses. Such characteristics can boost its potential to be used as an additive manufacturing technique. Indeed, deposition via cold spray is recently finding its path toward fabrication of freeform components since it can address the common challenges of powder-bed additive manufacturing techniques including major size constraints, deposition rate limitations and high process temperature. Herein, we prepared nickel-based superalloy Inconel 718 samples with cold spray technique and compared them with similar samples fabricated by selective laser melting method. The samples fabricated using both methods were characterized in terms of mechanical strength, microstructural and porosity characteristics, Vickers microhardness and residual stresses distribution. Different heat treatment cycles were applied to the cold-sprayed samples in order to enhance their mechanical characteristics. The obtained data confirm that cold spray technique can be used as a complementary additive manufacturing method for fabrication of high-quality freestanding components where higher deposition rate, larger final size and lower fabrication temperatures are desired.

  16. 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.

  17. 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.

  18. 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.

  19. X-Ray Temperatures, Luminosities, and Masses from XMM-Newton Follow-up of the First Shear-selected Galaxy Cluster Sample

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, Amruta J.; Hughes, John P. [Department of Physics and Astronomy, Rutgers the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Wittman, David, E-mail: amrejd@physics.rutgers.edu, E-mail: jph@physics.rutgers.edu, E-mail: dwittman@physics.ucdavis.edu [Department of Physics, University of California, Davis, One Shields Avenue, Davis, CA 95616 (United States)

    2017-04-20

    We continue the study of the first sample of shear-selected clusters from the initial 8.6 square degrees of the Deep Lens Survey (DLS); a sample with well-defined selection criteria corresponding to the highest ranked shear peaks in the survey area. We aim to characterize the weak lensing selection by examining the sample’s X-ray properties. There are multiple X-ray clusters associated with nearly all the shear peaks: 14 X-ray clusters corresponding to seven DLS shear peaks. An additional three X-ray clusters cannot be definitively associated with shear peaks, mainly due to large positional offsets between the X-ray centroid and the shear peak. Here we report on the XMM-Newton properties of the 17 X-ray clusters. The X-ray clusters display a wide range of luminosities and temperatures; the L {sub X} − T {sub X} relation we determine for the shear-associated X-ray clusters is consistent with X-ray cluster samples selected without regard to dynamical state, while it is inconsistent with self-similarity. For a subset of the sample, we measure X-ray masses using temperature as a proxy, and compare to weak lensing masses determined by the DLS team. The resulting mass comparison is consistent with equality. The X-ray and weak lensing masses show considerable intrinsic scatter (∼48%), which is consistent with X-ray selected samples when their X-ray and weak lensing masses are independently determined.

  20. 40 CFR Appendix A to Subpart F of... - Sampling Plans for Selective Enforcement Auditing of Nonroad Engines

    Science.gov (United States)

    2010-07-01

    ... Enforcement Auditing of Nonroad Engines A Appendix A to Subpart F of Part 89 Protection of Environment... NONROAD COMPRESSION-IGNITION ENGINES Selective Enforcement Auditing Pt. 89, Subpt. F, App. A Appendix A to Subpart F of Part 89—Sampling Plans for Selective Enforcement Auditing of Nonroad Engines Table 1—Sampling...

  1. 40 CFR Appendix A to Subpart G of... - Sampling Plans for Selective Enforcement Auditing of Marine Engines

    Science.gov (United States)

    2010-07-01

    ... Enforcement Auditing of Marine Engines A Appendix A to Subpart G of Part 91 Protection of Environment...-IGNITION ENGINES Selective Enforcement Auditing Regulations Pt. 91, Subpt. G, App. A Appendix A to Subpart G of Part 91—Sampling Plans for Selective Enforcement Auditing of Marine Engines Table 1—Sampling...

  2. Parameter selection for peak alignment in chromatographic sample profiling: Objective quality indicators and use of control samples

    NARCIS (Netherlands)

    Peters, S.; van Velzen, E.; Janssen, H.-G.

    2009-01-01

    In chromatographic profiling applications, peak alignment is often essential as most chromatographic systems exhibit small peak shifts over time. When using currently available alignment algorithms, there are several parameters that determine the outcome of the alignment process. Selecting the

  3. OBJECTS IN KEPLER'S MIRROR MAY BE LARGER THAN THEY APPEAR: BIAS AND SELECTION EFFECTS IN TRANSITING PLANET SURVEYS

    International Nuclear Information System (INIS)

    Gaidos, Eric; Mann, Andrew W.

    2013-01-01

    Statistical analyses of large surveys for transiting planets such as the Kepler mission must account for systematic errors and biases. Transit detection depends not only on the planet's radius and orbital period, but also on host star properties. Thus, a sample of stars with transiting planets may not accurately represent the target population. Moreover, targets are selected using criteria such as a limiting apparent magnitude. These selection effects, combined with uncertainties in stellar radius, lead to biases in the properties of transiting planets and their host stars. We quantify possible biases in the Kepler survey. First, Eddington bias produced by a steep planet radius distribution and uncertainties in stellar radius results in a 15%-20% overestimate of planet occurrence. Second, the magnitude limit of the Kepler target catalog induces Malmquist bias toward large, more luminous stars and underestimation of the radii of about one-third of candidate planets, especially those larger than Neptune. Third, because metal-poor stars are smaller, stars with detected planets will be very slightly (<0.02 dex) more metal-poor than the target average. Fourth, uncertainties in stellar radii produce correlated errors in planet radius and stellar irradiation. A previous finding, that highly irradiated giants are more likely to have 'inflated' radii, remains significant, even accounting for this effect. In contrast, transit depth is negatively correlated with stellar metallicity even in the absence of any intrinsic correlation, and a previous claim of a negative correlation between giant planet transit depth and stellar metallicity is probably an artifact.

  4. 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.

  5. Selective extraction of dimethoate from cucumber samples by use of molecularly imprinted microspheres

    Directory of Open Access Journals (Sweden)

    Jiao-Jiao Du

    2015-06-01

    Full Text Available Molecularly imprinted polymers for dimethoate recognition were synthesized by the precipitation polymerization technique using methyl methacrylate (MMA as the functional monomer and ethylene glycol dimethacrylate (EGDMA as the cross-linker. The morphology, adsorption and recognition properties were investigated by scanning electron microscopy (SEM, static adsorption test, and competitive adsorption test. To obtain the best selectivity and binding performance, the synthesis and adsorption conditions of MIPs were optimized through single factor experiments. Under the optimized conditions, the resultant polymers exhibited uniform size, satisfactory binding capacity and significant selectivity. Furthermore, the imprinted polymers were successfully applied as a specific solid-phase extractants combined with high performance liquid chromatography (HPLC for determination of dimethoate residues in the cucumber samples. The average recoveries of three spiked samples ranged from 78.5% to 87.9% with the relative standard deviations (RSDs less than 4.4% and the limit of detection (LOD obtained for dimethoate as low as 2.3 μg/mL. Keywords: Molecularly imprinted polymer, Precipitation polymerization, Dimethoate, Cucumber, HPLC

  6. A MID-INFRARED IMAGING SURVEY OF SUBMILLIMETER-SELECTED GALAXIES WITH THE SPITZER SPACE TELESCOPE

    International Nuclear Information System (INIS)

    Hainline, Laura J.; Blain, A. W.; Smail, Ian; Frayer, D. T.; Chapman, S. C.; Ivison, R. J.; Alexander, D. M.

    2009-01-01

    We present Spitzer-IRAC and MIPS mid-IR observations of a sample of 73 radio-detected submillimeter-selected galaxies (SMGs) with spectroscopic redshifts, the largest such sample published to date. From our data, we find that IRAC colors of SMGs are much more uniform as compared with rest-frame UV and optical colors, and z>1.5 SMGs tend to be redder in their mid-IR colors than both field galaxies and lower-z SMGs. However, the IRAC colors of the SMGs overlap those of field galaxies sufficiently that color-magnitude and color-color selection criteria suggested in the literature to identify SMG counterparts produce ambiguous counterparts within an 8'' radius in 20%-35% of cases. We use a rest-frame J-H versus H-K color-color diagram and a S 24 /S 8.0 versus S 8.0 /S 4.5 color-color diagram to determine that 13%-19% of our sample are likely to contain active galactic nuclei which dominate their mid-IR emission. We observe in the rest-frame JHK colors of our sample that the rest-frame near-IR emission of SMGs does not resemble that of the compact nuclear starburst observed in local ultraluminous IR galaxies and is consistent with more widely distributed star formation. We take advantage of the fact that many high-z galaxy populations selected at different wavelengths are detected by Spitzer to carry out a brief comparison of mid-IR properties of SMGs to UV-selected high-z galaxies, 24 μm-selected galaxies, and high-z radio galaxies, and find that SMGs have mid-IR fluxes and colors which are consistent with being more massive and more reddened than UV-selected galaxies, while the IRAC colors of SMGs are most similar to powerful high-z radio galaxies.

  7. A quick method based on SIMPLISMA-KPLS for simultaneously selecting outlier samples and informative samples for model standardization in near infrared spectroscopy

    Science.gov (United States)

    Li, Li-Na; Ma, Chang-Ming; Chang, Ming; Zhang, Ren-Cheng

    2017-12-01

    A novel method based on SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) and Kernel Partial Least Square (KPLS), named as SIMPLISMA-KPLS, is proposed in this paper for selection of outlier samples and informative samples simultaneously. It is a quick algorithm used to model standardization (or named as model transfer) in near infrared (NIR) spectroscopy. The NIR experiment data of the corn for analysis of the protein content is introduced to evaluate the proposed method. Piecewise direct standardization (PDS) is employed in model transfer. And the comparison of SIMPLISMA-PDS-KPLS and KS-PDS-KPLS is given in this research by discussion of the prediction accuracy of protein content and calculation speed of each algorithm. The conclusions include that SIMPLISMA-KPLS can be utilized as an alternative sample selection method for model transfer. Although it has similar accuracy to Kennard-Stone (KS), it is different from KS as it employs concentration information in selection program. This means that it ensures analyte information is involved in analysis, and the spectra (X) of the selected samples is interrelated with concentration (y). And it can be used for outlier sample elimination simultaneously by validation of calibration. According to the statistical data results of running time, it is clear that the sample selection process is more rapid when using KPLS. The quick algorithm of SIMPLISMA-KPLS is beneficial to improve the speed of online measurement using NIR spectroscopy.

  8. 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

  9. Selective whole genome amplification for resequencing target microbial species from complex natural samples.

    Science.gov (United States)

    Leichty, Aaron R; Brisson, Dustin

    2014-10-01

    Population genomic analyses have demonstrated power to address major questions in evolutionary and molecular microbiology. Collecting populations of genomes is hindered in many microbial species by the absence of a cost effective and practical method to collect ample quantities of sufficiently pure genomic DNA for next-generation sequencing. Here we present a simple method to amplify genomes of a target microbial species present in a complex, natural sample. The selective whole genome amplification (SWGA) technique amplifies target genomes using nucleotide sequence motifs that are common in the target microbe genome, but rare in the background genomes, to prime the highly processive phi29 polymerase. SWGA thus selectively amplifies the target genome from samples in which it originally represented a minor fraction of the total DNA. The post-SWGA samples are enriched in target genomic DNA, which are ideal for population resequencing. We demonstrate the efficacy of SWGA using both laboratory-prepared mixtures of cultured microbes as well as a natural host-microbe association. Targeted amplification of Borrelia burgdorferi mixed with Escherichia coli at genome ratios of 1:2000 resulted in >10(5)-fold amplification of the target genomes with genomic extracts from Wolbachia pipientis-infected Drosophila melanogaster resulted in up to 70% of high-throughput resequencing reads mapping to the W. pipientis genome. By contrast, 2-9% of sequencing reads were derived from W. pipientis without prior amplification. The SWGA technique results in high sequencing coverage at a fraction of the sequencing effort, thus allowing population genomic studies at affordable costs. Copyright © 2014 by the Genetics Society of America.

  10. Selective reporting of antibiotic susceptibility test results in European countries: an ESCMID cross-sectional survey.

    Science.gov (United States)

    Pulcini, Céline; Tebano, Gianpiero; Mutters, Nico T; Tacconelli, Evelina; Cambau, Emmanuelle; Kahlmeter, Gunnar; Jarlier, Vincent

    2017-02-01

    Selective reporting of antibiotic susceptibility test (AST) results is one possible laboratory-based antibiotic stewardship intervention. The primary aim of this study was to identify where and how selective reporting of AST results is implemented in Europe both in inpatient and in outpatient settings. An ESCMID cross-sectional, self-administered, internet-based survey was conducted among all EUCIC (European Committee on Infection Control) or EUCAST (European Committee on Antimicrobial Susceptibility Testing) national representatives in Europe and Israel. Of 38 countries, 36 chose to participate in the survey. Selective reporting of AST results was implemented in 11/36 countries (31%), was partially implemented in 4/36 (11%) and was limited to local initiatives or was not adopted in 21/36 (58%). It was endorsed as standard of care by health authorities in only three countries. The organisation of selective reporting was everywhere discretionally managed by each laboratory, with a pronounced intra- and inter-country variability. The most frequent application was in uncomplicated community-acquired infections, particularly urinary tract and skin and soft-tissue infections. The list of reported antibiotics ranged from a few first-line options, to longer reports where only last-resort antibiotics were hidden. Several barriers to implementation were reported, mainly lack of guidelines, poor system support, insufficient resources, and lack of professionals' capability. In conclusion, selective reporting of AST results is poorly implemented in Europe and is applied with a huge heterogeneity of practices. Development of an international framework, based on existing initiatives and identified barriers, could favour its dissemination as one important element of antibiotic stewardship programmes. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  11. Geophysical survey aimed at selecting the radioactive waste repository site (Czech republic

    Directory of Open Access Journals (Sweden)

    Dušan Dostál

    2007-01-01

    Full Text Available G IMPULS Praha has been executing a set of geophysical measurements for the Radioactive Waste Repository Authority of the Czech Republic from 2001 (the work continues to be carried out. The measurements are aimed at studying the behaviour of the rock massif, focusing on the Excavation Damaged or Disturbed Zone (EDZ and on selecting an appropriate area for the radioactive material repository site. The geophysical studies use a complex of methods as follows: Airborne geophysical measurement (regional studies, Seismic measurement (detailed studies, G.P.R. (detailed studies, Resistivity tomography (detailed studies, Geoelectric measurement and magnetic survey (stray earth currents. The paper informs about first results and conclusions. The airborne work was executed as a part of the complex study of „GEOBARIERA“ the group and the geophysical measurements of EDZ were executed in co-operation with the Czech Geological Survey.

  12. Determination of specific activity of americium and plutonium in selected environmental samples

    International Nuclear Information System (INIS)

    Trebunova, T.

    1999-01-01

    The aim of this work was development of method for determination of americium and plutonium in environmental samples. Developed method was evaluated on soil samples and after they was applied on selected samples of fishes (smoked mackerel, herring and fillet from Alaska hake). The method for separation of americium is based on liquid separation with Aliquate-336, precipitation with oxalic acid and using of chromatographic material TRU-Spec TM .The intervals of radiochemical yields were from 13.0% to 80.9% for plutonium-236 and from 10.5% to 100% for americium-241. Determined specific activities of plutonium-239,240 were from (2.3 ± 1.4) mBq/kg to (82 ± 29) mBq/kg, the specific activities of plutonium-238 were from (14.2 ± 3.7) mBq/kg to (708 ± 86) mBq/kg. The specific activities of americium-241 were from (1.4 ± 0.9) mBq/kg to (3360 ± 210) mBq/kg. The fishes from Baltic Sea as well as from North Sea show highest specific activities then fresh-water fishes from Slovakia. Therefore the monitoring of alpha radionuclides in foods imported from territories with nuclear testing is recommended

  13. 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

  14. Spectral Characterization of H2020/PTAL Mineral Samples: Implications for In Situ Martian Exploration and Mars Sample Selection

    Science.gov (United States)

    Lantz, C.; Pilorget, C.; Poulet, F.; Riu, L.; Dypvik, H.; Hellevang, H.; Rull Perez, F.; Veneranda, M.; Cousin, A.; Viennet, J.-C.; Werner, S. C.

    2018-04-01

    We present combined analysis performed in the framework of the Planetary Terrestrial Analogues Library (H2020 project). XRD, NIR, Raman, and LIBS spectroscopies are used to characterise samples to prepare ExoMars/ESA and Mars2020/NASA observations.

  15. 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.

  16. A survey of variable selection methods in two Chinese epidemiology journals

    Directory of Open Access Journals (Sweden)

    Lynn Henry S

    2010-09-01

    Full Text Available Abstract Background Although much has been written on developing better procedures for variable selection, there is little research on how it is practiced in actual studies. This review surveys the variable selection methods reported in two high-ranking Chinese epidemiology journals. Methods Articles published in 2004, 2006, and 2008 in the Chinese Journal of Epidemiology and the Chinese Journal of Preventive Medicine were reviewed. Five categories of methods were identified whereby variables were selected using: A - bivariate analyses; B - multivariable analysis; e.g. stepwise or individual significance testing of model coefficients; C - first bivariate analyses, followed by multivariable analysis; D - bivariate analyses or multivariable analysis; and E - other criteria like prior knowledge or personal judgment. Results Among the 287 articles that reported using variable selection methods, 6%, 26%, 30%, 21%, and 17% were in categories A through E, respectively. One hundred sixty-three studies selected variables using bivariate analyses, 80% (130/163 via multiple significance testing at the 5% alpha-level. Of the 219 multivariable analyses, 97 (44% used stepwise procedures, 89 (41% tested individual regression coefficients, but 33 (15% did not mention how variables were selected. Sixty percent (58/97 of the stepwise routines also did not specify the algorithm and/or significance levels. Conclusions The variable selection methods reported in the two journals were limited in variety, and details were often missing. Many studies still relied on problematic techniques like stepwise procedures and/or multiple testing of bivariate associations at the 0.05 alpha-level. These deficiencies should be rectified to safeguard the scientific validity of articles published in Chinese epidemiology journals.

  17. 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.

  18. Star formation rates in isolated galaxies selected from the Two-Micron All-Sky Survey

    Science.gov (United States)

    Melnyk, O.; Karachentseva, V.; Karachentsev, I.

    2015-08-01

    We have considered the star formation properties of 1616 isolated galaxies from the 2MASS XSC (Extended Source Catalog) selected sample (2MIG) with the far-ultraviolet GALEX magnitudes. This sample was then compared with corresponding properties of isolated galaxies from the Local Orphan Galaxies (LOG) catalogue and paired galaxies. We found that different selection algorithms define different populations of isolated galaxies. The population of the LOG catalogue, selected from non-clustered galaxies in the Local Supercluster volume, mostly consists of low-mass spiral and late-type galaxies. The specific star formation rate (SSFR) upper limit in isolated and paired galaxies does not exceed the value of ˜dex(-9.4). This is probably common for galaxies of differing activity and environment (at least at z processes is the galaxy mass. However, the environmental influence is notable: paired massive galaxies with logM* > 11.5 have higher (S)SFR than isolated galaxies. Our results suggest that the environment helps to trigger the star formation in the highest mass galaxies. We found that the fraction of AGN in the paired sample is only a little higher than in our isolated galaxy sample. We assume that AGN phenomenon is probably defined by secular galaxy evolution.

  19. 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.

  20. Concentration of ions in selected bottled water samples sold in Malaysia

    Science.gov (United States)

    Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

    2013-03-01

    Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

  1. 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.

  2. 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.

  3. 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.

  4. Calibration model maintenance in melamine resin production: Integrating drift detection, smart sample selection and model adaptation.

    Science.gov (United States)

    Nikzad-Langerodi, Ramin; Lughofer, Edwin; Cernuda, Carlos; Reischer, Thomas; Kantner, Wolfgang; Pawliczek, Marcin; Brandstetter, Markus

    2018-07-12

    selection of samples by active learning (AL) used for subsequent model adaptation is advantageous compared to passive (random) selection in case that a drift leads to persistent prediction bias allowing more rapid adaptation at lower reference measurement rates. Fully unsupervised adaptation using FLEXFIS-PLS could improve predictive accuracy significantly for light drifts but was not able to fully compensate for prediction bias in case of significant lack of fit w.r.t. the latent variable space. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. The Selected Method and Tools for Performance Measurement in the Green Supply Chain—Survey Analysis in Poland

    Directory of Open Access Journals (Sweden)

    Blanka Tundys

    2018-02-01

    Full Text Available The methods and tools for the performance measurement and evaluation of the green supply chain management are very important elements for the construction and function of this type of supply chain. The result is a presentation of the considerations underlying a very general model, which presents some selected tools, but no breakdown of individual industries. The considerations undertaken are important and have scientific added value as usually in practice, a very large number of tools are used to assess the supply chain, which are not always correlated or adapted to the specificity of the chain. It is worth pointing out which of the already used or completely new tools and methods will be most useful for assessing the green supply chain. The structure of the paper covers the theoretical and empirical. It includes an introduction, our goals and hypotheses, state of the art, methodology, empirical findings, and discussion. We present the definitional differences between green and sustainable supply chains and focus on the selection and identification of methods for the framework model for evaluating the green supply chain. In the next step, the theoretical and selected method and tools were compared to a survey of Poland. On the basis of the survey, we present the findings and discussions found in this area. The main methodology used includes a literature review, a survey analysis using a questionnaire and statistical tools. The survey was carried out in 2015 in sample organizations in Poland. The research results showed that organizations were aware of the environmental elements of measuring and assessing the supply chain from an environmental point of view, but their use depended on many factors: the area, size of the organization, or the industry. If certain boundary conditions are met and the organizations are aware of the essence of environmental aspects in the chain, then they are applying green measures to the supply chain. These findings

  6. The Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected Via the Sunyaev-Zel'Dovich Effect

    Science.gov (United States)

    Menanteau, Felipe; Gonzalez, Jorge; Juin, Jean-Baptiste; Marriage, Tobias; Reese, Erik D.; Acquaviva, Viviana; Aguirre, Paula; Appel, John Willam; Baker, Andrew J.; Barrientos, L. Felipe; hide

    2010-01-01

    We present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich Effect from 148 GHz maps over 455 square degrees of sky made with the Atacama Cosmology Telescope. These maps. coupled with multi-band imaging on 4-meter-class optical telescopes, have yielded a sample of 23 galaxy clusters with redshifts between 0.118 and 1.066. Of these 23 clusters, 10 are newly discovered. The selection of this sample is approximately mass limited and essentially independent of redshift. We provide optical positions, images, redshifts and X-ray fluxes and luminosities for the full sample, and X-ray temperatures of an important subset. The mass limit of the full sample is around 8.0 x 10(exp 14) Stellar Mass. with a number distribution that peaks around a redshift of 0.4. For the 10 highest significance SZE-selected cluster candidates, all of which are optically confirmed, the mass threshold is 1 x 10(exp 15) Stellar Mass and the redshift range is 0.167 to 1.066. Archival observations from Chandra, XMM-Newton. and ROSAT provide X-ray luminosities and temperatures that are broadly consistent with this mass threshold. Our optical follow-up procedure also allowed us to assess the purity of the ACT cluster sample. Eighty (one hundred) percent of the 148 GHz candidates with signal-to-noise ratios greater than 5.1 (5.7) are confirmed as massive clusters. The reported sample represents one of the largest SZE-selected sample of massive clusters over all redshifts within a cosmologically-significant survey volume, which will enable cosmological studies as well as future studies on the evolution, morphology, and stellar populations in the most massive clusters in the Universe.

  7. Source selection for cluster weak lensing measurements in the Hyper Suprime-Cam survey

    Science.gov (United States)

    Medezinski, Elinor; Oguri, Masamune; Nishizawa, Atsushi J.; Speagle, Joshua S.; Miyatake, Hironao; Umetsu, Keiichi; Leauthaud, Alexie; Murata, Ryoma; Mandelbaum, Rachel; Sifón, Cristóbal; Strauss, Michael A.; Huang, Song; Simet, Melanie; Okabe, Nobuhiro; Tanaka, Masayuki; Komiyama, Yutaka

    2018-03-01

    We present optimized source galaxy selection schemes for measuring cluster weak lensing (WL) mass profiles unaffected by cluster member dilution from the Subaru Hyper Suprime-Cam Strategic Survey Program (HSC-SSP). The ongoing HSC-SSP survey will uncover thousands of galaxy clusters to z ≲ 1.5. In deriving cluster masses via WL, a critical source of systematics is contamination and dilution of the lensing signal by cluster members, and by foreground galaxies whose photometric redshifts are biased. Using the first-year CAMIRA catalog of ˜900 clusters with richness larger than 20 found in ˜140 deg2 of HSC-SSP data, we devise and compare several source selection methods, including selection in color-color space (CC-cut), and selection of robust photometric redshifts by applying constraints on their cumulative probability distribution function (P-cut). We examine the dependence of the contamination on the chosen limits adopted for each method. Using the proper limits, these methods give mass profiles with minimal dilution in agreement with one another. We find that not adopting either the CC-cut or P-cut methods results in an underestimation of the total cluster mass (13% ± 4%) and the concentration of the profile (24% ± 11%). The level of cluster contamination can reach as high as ˜10% at R ≈ 0.24 Mpc/h for low-z clusters without cuts, while employing either the P-cut or CC-cut results in cluster contamination consistent with zero to within the 0.5% uncertainties. Our robust methods yield a ˜60 σ detection of the stacked CAMIRA surface mass density profile, with a mean mass of M200c = [1.67 ± 0.05(stat)] × 1014 M⊙/h.

  8. Report on the achievements in the Sunshine Project in fiscal 1987. Surveys on coal selection and coal types (Surveys on coal resources for liquefaction); 1987 nendo tanshu sentei chosa tanshu chosa seika hokokusho. Ekikayo sekitan shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-03-01

    The survey purpose is to identify availability of coal resources for liquefaction in major coal producing countries in the Pacific basin area. Therefore, collection is carried out on such data as coal existing conditions, coal qualities, production quantities, and infrastructures on coal mines being operated and projects under development or investigation. Coal samples are collected in wide range and exhaustively unbiased to particular coal fields and mines to acquire data to perform selection and evaluation of coals that can be fed to coal liquefying plants. The present survey was intended to acquire fundamental data for the liquefying coal selection, such as coal existing conditions, natures, and infrastructures for the coal resources, taking up as the survey object countries the State of Alaska, U.S.A. and Indonesia. The coal types as the object of the survey are mainly sub-bituminous coal, and additionally brown coal and partly bituminous coal. The amount of coal deposit as the subject of the investigation is 100 million tons or more as the verified reserve. The subject areas cover coal mines in the State of Alaska, U.S.A. (Northern Alaska, Nenana, Beluga, and Matanuska coal fields), and Indonesia (the Sumatra and Kalimantan islands). The survey items are made up of 14 items (see the coal mine survey tables in JN0040851). (NEDO)

  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. Dietary trace element intakes of a selected sample of Canadian elderly women

    International Nuclear Information System (INIS)

    Gibson, R.S.; MacDonald, A.C.; Martinez, O.B.

    1984-01-01

    Energy, and selected trace intakes of a sample of 90 noninstitutionalized Canadian women (mean age 66.2 +/- 6.2 years) living in a University community and consuming self-selected diets were assessed by chemical analysis of one-day duplicate diets and via 1-day dietary records collected by the subjects. Mean gross energy intake (determined via bomb calorimetry was 6.0 +/- 2.4 MJ (1435 +/- 580 kcal) and mean intakes of Cu and Mn (determined via atomic absorption spectrophotometry) were 1.2 +/- 0.6 mg and 3.8 +/- 2.1 mg/day, respectively. Instrumental neutron activation analysis was used for Cr - median = 77.4 μg/day; Se - median = 69.6 μg/day; Zn - mean + SD = 7.7 +/- 3.6 mg/day; Ag - median = 26.9 μg/day; Cs - median = 4.8 μg/day; Rb - median = 1.6 mg/day; Sb - median = 1.8 μg/day; Sc - median = 0.3 μg/day. Dietary intakes of Cr, Mn and Se for the majority of the subjects fell within the US safe and adequate range. In contrast, a high proportion of subjects had apparently low intakes of dietary Cu and Zn in relation to current US dietary recommendations

  11. Determination of Nd3+ Ions in Solution Samples by a Coated Wire Ion-Selective Sensor

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2012-01-01

    Full Text Available A new coated wire electrode (CWE using 5-(methylsulfanyl-3-phenyl-1H-1,2,4-triazole (MPT as an ionophore has been developed as a neodymium ion-selective sensor. The sensor exhibits Nernstian response for the Nd3+ ions in the concentration range of 1.0×10−6-1.0×10−2 M with detection limit of 3.7×10−7 M. It displays a Nernstian slope of 20.2±0.2 mV/decade in the pH range of 2.7–8.1. The proposed sensor also exhibits a fast response time of ∼5 s. The sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The electrode was used as an indicator electrode in the potentiometric titration of Nd(III ions with EDTA. The electrode was also employed for the determination of the Nd3+ ions concentration in water solution samples.

  12. Semi-selective medium for Fusarium graminearum detection in seed samples

    Directory of Open Access Journals (Sweden)

    Marivane Segalin

    2010-12-01

    Full Text Available Fungi of the genus Fusarium cause a variety of difficult to control diseases in different crops, including winter cereals and maize. Among the species of this genus Fusarium graminearum deserves attention. The aim of this work was to develop a semi-selective medium to study this fungus. In several experiments, substrates for fungal growth were tested, including fungicides and antibiotics such as iprodiona, nystatin and triadimenol, and the antibacterial agents streptomycin and neomycin sulfate. Five seed samples of wheat, barley, oat, black beans and soybeans for F. graminearum detection by using the media Nash and Snyder agar (NSA, Segalin & Reis agar (SRA and one-quarter dextrose agar (1/4PDA; potato 50g; dextrose 5g and agar 20g, either unsupplemented or supplemented with various concentrations of the antimicrobial agents cited above. The selected components and concentrations (g.L-1 of the proposed medium, Segalin & Reis agar (SRA-FG, were: iprodiona 0.05; nystatin 0,025; triadimenol 0.015; neomycin sulfate 0.05; and streptomycin sulfate, 0.3 added of ¼ potato sucrose agar. In the isolation from seeds of cited plant species, the sensitivity of this medium was similar to that of NSA but with de advantage of maintaining the colony morphological aspects similar to those observed in potato-dextrose-agar medium.

  13. A boy or a girl? A Hungarian survey regarding gender selection.

    Science.gov (United States)

    Fejes, Imre; Szöllosi, János; Závaczki, Zoltán; Koloszár, Sándor; Pál, Attila

    2006-01-01

    Infertile Hungarian couples were surveyed with regard to their opinion of preconception gender selection by the separation of X- and Y-bearing sperm populations. Self-completion of a questionnaire. Group 1: subjects presenting for infertility examination; Group 2: presenting for homologous intrauterine insemination. As concerns the gender of the firstborn, 13.8% of those in Group 1 preferred a boy and 10.3% a girl, while 75.9% had no preference. The male preference was higher in Group 2: 33.3% preferred a boy and 7.4% a girl while 59.3% had no preference (chi 2, p gender. In Group 2, 30.8% were willing to pay the extra costs for a gender selection procedure as compared with only 10.8% of the couples in Group 1 (chi 2, p equal numbers of male and female children. The utilization of preconception gender selection, therefore, would not seem to appreciably affect the natural male/female ratio. Genetic indications exert significant effects on the decision regarding sex selection procedures.

  14. Probing BL Lac and Cluster Evolution via a Wide-angle, Deep X-ray Selected Sample

    Science.gov (United States)

    Perlman, E.; Jones, L.; White, N.; Angelini, L.; Giommi, P.; McHardy, I.; Wegner, G.

    1994-12-01

    The WARPS survey (Wide-Angle ROSAT Pointed Survey) has been constructed from the archive of all public ROSAT PSPC observations, and is a subset of the WGACAT catalog. WARPS will include a complete sample of >= 100 BL Lacs at F_x >= 10(-13) erg s(-1) cm(-2) . A second selection technique will identify ~ 100 clusters at 0.15 = 0.304 +/- 0.062 for XBLs but = 0.60 +/- 0.05 for RBLs. Models of the X-ray luminosity function (XLF) are also poorly constrained. WARPS will allow us to compute an accurate XLF, decreasing the error bars above by over a factor of two. We will also test for low-luminosity BL Lacs, whose non-thermal nuclear sources are dim compared to the host galaxy. Browne and Marcha (1993) claim the EMSS missed most of these objects and is incomplete. If their predictions are correct, 20-40% of the BL Lacs we find will fall in this category, enabling us to probe the evolution and internal workings of BL Lacs at lower luminosities than ever before. By removing likely QSOs before optical spectroscopy, WARPS requires only modest amounts of telescope time. It will extend measurement of the cluster XLF both to higher redshifts (z>0.5) and lower luminosities (LX<1x10(44) erg s(-1) ) than previous measurements, confirming or rejecting the 3sigma detection of negative evolution found in the EMSS, and constraining Cold Dark Matter cosmologies. Faint NELGs are a recently discovered major contributor to the X-ray background. They are a mixture of Sy2s, starbursts and galaxies of unknown type. Detailed classification and evolution of their XLF will be determined for the first time.

  15. [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.

  16. 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

  17. Correcting Classifiers for Sample Selection Bias in Two-Phase Case-Control Studies

    Science.gov (United States)

    Theis, Fabian J.

    2017-01-01

    Epidemiological studies often utilize stratified data in which rare outcomes or exposures are artificially enriched. This design can increase precision in association tests but distorts predictions when applying classifiers on nonstratified data. Several methods correct for this so-called sample selection bias, but their performance remains unclear especially for machine learning classifiers. With an emphasis on two-phase case-control studies, we aim to assess which corrections to perform in which setting and to obtain methods suitable for machine learning techniques, especially the random forest. We propose two new resampling-based methods to resemble the original data and covariance structure: stochastic inverse-probability oversampling and parametric inverse-probability bagging. We compare all techniques for the random forest and other classifiers, both theoretically and on simulated and real data. Empirical results show that the random forest profits from only the parametric inverse-probability bagging proposed by us. For other classifiers, correction is mostly advantageous, and methods perform uniformly. We discuss consequences of inappropriate distribution assumptions and reason for different behaviors between the random forest and other classifiers. In conclusion, we provide guidance for choosing correction methods when training classifiers on biased samples. For random forests, our method outperforms state-of-the-art procedures if distribution assumptions are roughly fulfilled. We provide our implementation in the R package sambia. PMID:29312464

  18. Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

    Science.gov (United States)

    Venturini, Elisa; Vassura, Ivano; Raffo, Simona; Ferroni, Laura; Bernardi, Elena; Passarini, Fabrizio

    2014-10-01

    In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.

  19. Characteristic of selected frequency luminescence for samples collected in deserts north to Beijing

    International Nuclear Information System (INIS)

    Li Dongxu; Wei Mingjian; Wang Junping; Pan Baolin; Zhao Shiyuan; Liu Zhaowen

    2009-01-01

    Surface sand samples were collected in eight sites of the Horqin and Otindag deserts located in north to Beijing. BG2003 luminescence spectrograph was used to analyze the emitted photons and characteristic spectra of the selected frequency luminescence were obtained. It was found that high intensities of emitted photons stimulated by heat from 85 degree C-135 degree C and 350 degree C-400 degree C. It belong to the traps of 4.13 eV (300 nm), 4.00 eV (310 nm), 3.88 eV (320 nm) and 2.70 eV (460 nm), and the emitted photons belong to traps of 4.00 eV (310 nm), 3.88 eV (320 nm) and 2.70 eV (460 nm) were stimulated by green laser. And sand samples of the eight sites can respond to the increase of definite radiological dose at each wavelength, which is the characteristic spectrum to provide radiation dosimetry basis for dating. There are definite district characteristic in their characteristic spectra. (authors)

  20. Clinical impact of strict criteria for selectivity and lateralization in adrenal vein sampling.

    Science.gov (United States)

    Gasparetto, Alessandro; Angle, John F; Darvishi, Pasha; Freeman, Colbey W; Norby, Ray G; Carey, Robert M

    2015-04-01

    Selectivity index (SI) and lateralization index (LI) thresholds determine the adequacy of adrenal vein sampling (AVS) and the degree of lateralization. The purpose of this study was investigate the clinical outcome of patients whose adrenal vein sampling was interpreted using "strict criteria" (SC) (SIpre-stimuli≥3, SIpost-stimuli≥5 and LIpre-stimuli≥4, LIpost-stimuli≥4). A retrospective review of 73 consecutive AVS procedures was performed and 67 were technically successful. Forty-three patients showed lateralization and underwent surgery, while 24 did not lateralize and were managed conservatively. Systolic blood pressure (SBP), diastolic blood pressure (DBP), kalemia (K(+)), and the change in number of blood pressure (BP) medications were recorded for each patient before and after AVS and potential surgery were performed. In the surgery group, BP and K(+) changed respectively from 160±5.3/100±2.0 mmHg to 127±3.3/80±1.9 (p blood pressure medications were six (14.0%) in the lateralized group and 22 (91.7%) in the non-lateralized group (p <0.001). AVS interpretation with SC leads to significant clinical improvement in both patients who underwent surgery and those managed conservatively.

  1. Wetland survey of selected areas in the K-24 Site Area of responsibility

    Energy Technology Data Exchange (ETDEWEB)

    Rosensteel, B.A.; Awl, D.J. [JAYCOR, Environmental Division, Oak Ridge, TN (United States)

    1995-07-01

    In accordance with DOE Regulations for Compliance with Floodplain/Wetlands Environmental Review Requirements, wetland surveys were conducted in selected areas within the K-25 Area of Responsibility during the summer of 1994. These areas are Mitchell Branch, Poplar Creek, the K-770 OU, Duct Island Peninsula, the Powerhouse area, and the K-25 South Corner. Previously surveyed areas included in this report are the main plant area of the K-25 Site, the K-901 OU, the AVLIS site, and the K-25 South Site. Wetland determinations were based on the USACE methodology. Forty-four separate wetland areas, ranging in size from 0.13 to 4.23 ha, were identified. Wetlands were identified in all of the areas surveyed with the exception of the interior of the Duct Island Peninsula and the main plant area of the K-25 Site. Wetlands perform functions such as floodflow alteration, sediment stabilization, sediment and toxicant retention, nutrient transformation, production export, and support of aquatic species and wildlife diversity and abundance. The forested, scrub-shrub, and emergent wetlands identified in the K-25 area perform some or all of these functions to varying degrees.

  2. Wetland survey of selected areas in the K-24 Site Area of responsibility

    International Nuclear Information System (INIS)

    Rosensteel, B.A.; Awl, D.J.

    1995-07-01

    In accordance with DOE Regulations for Compliance with Floodplain/Wetlands Environmental Review Requirements, wetland surveys were conducted in selected areas within the K-25 Area of Responsibility during the summer of 1994. These areas are Mitchell Branch, Poplar Creek, the K-770 OU, Duct Island Peninsula, the Powerhouse area, and the K-25 South Corner. Previously surveyed areas included in this report are the main plant area of the K-25 Site, the K-901 OU, the AVLIS site, and the K-25 South Site. Wetland determinations were based on the USACE methodology. Forty-four separate wetland areas, ranging in size from 0.13 to 4.23 ha, were identified. Wetlands were identified in all of the areas surveyed with the exception of the interior of the Duct Island Peninsula and the main plant area of the K-25 Site. Wetlands perform functions such as floodflow alteration, sediment stabilization, sediment and toxicant retention, nutrient transformation, production export, and support of aquatic species and wildlife diversity and abundance. The forested, scrub-shrub, and emergent wetlands identified in the K-25 area perform some or all of these functions to varying degrees

  3. 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.

  4. Multiwavelength diagnostics of accretion in an X-ray selected sample of CTTSs

    Science.gov (United States)

    Curran, R. L.; Argiroffi, C.; Sacco, G. G.; Orlando, S.; Peres, G.; Reale, F.; Maggio, A.

    2011-02-01

    Context. High resolution X-ray spectroscopy has revealed soft X-rays from high density plasma in classical T Tauri stars (CTTSs), probably arising from the accretion shock region. However, the mass accretion rates derived from the X-ray observations are consistently lower than those derived from UV/optical/NIR studies. Aims: We aim to test the hypothesis that the high density soft X-ray emission originates from accretion by analysing, in a homogeneous manner, optical accretion indicators for an X-ray selected sample of CTTSs. Methods: We analyse optical spectra of the X-ray selected sample of CTTSs and calculate the accretion rates based on measuring the Hα, Hβ, Hγ, He ii 4686 Å, He i 5016 Å, He i 5876 Å, O i 6300 Å, and He i 6678 Å equivalent widths. In addition, we also calculate the accretion rates based on the full width at 10% maximum of the Hα line. The different optical tracers of accretion are compared and discussed. The derived accretion rates are then compared to the accretion rates derived from the X-ray spectroscopy. Results: We find that, for each CTTS in our sample, the different optical tracers predict mass-accretion rates that agree within the errors, albeit with a spread of ≈ 1 order of magnitude. Typically, mass-accretion rates derived from Hα and He i 5876 Å are larger than those derived from Hβ, Hγ, and O i. In addition, the Hα full width at 10%, whilst a good indicator of accretion, may not accurately measure the mass-accretion rate. When the optical mass-accretion rates are compared to the X-ray derived mass-accretion rates, we find that: a) the latter are always lower (but by varying amounts); b) the latter range within a factor of ≈ 2 around 2 × 10-10 M⊙ yr-1, despite the former spanning a range of ≈ 3 orders of magnitude. We suggest that the systematic underestimate of the X-ray derived mass-accretion rates could depend on the density distribution inside the accretion streams, where the densest part of the stream is

  5. Soil sampling intercomparison exercise by selected laboratories of the ALMERA Network

    International Nuclear Information System (INIS)

    2009-01-01

    The IAEA's Seibersdorf Laboratories in Austria have the programmatic responsibility to provide assistance to Member State laboratories in maintaining and improving the reliability of analytical measurement results, both in radionuclide and trace element determinations. This is accomplished through the provision of reference materials of terrestrial origin, validated analytical procedures, training in the implementation of internal quality control, and through the evaluation of measurement performance by the organization of worldwide and regional interlaboratory comparison exercises. The IAEA is mandated to support global radionuclide measurement systems related to accidental or intentional releases of radioactivity in the environment. To fulfil this obligation and ensure a reliable, worldwide, rapid and consistent response, the IAEA coordinates an international network of analytical laboratories for the measurement of environmental radioactivity (ALMERA). The network was established by the IAEA in 1995 and makes available to Member States a world-wide network of analytical laboratories capable of providing reliable and timely analysis of environmental samples in the event of an accidental or intentional release of radioactivity. A primary requirement for the ALMERA members is participation in the IAEA interlaboratory comparison exercises, which are specifically organized for ALMERA on a regular basis. These exercises are designed to monitor and demonstrate the performance and analytical capabilities of the network members, and to identify gaps and problem areas where further development is needed. In this framework, the IAEA organized a soil sampling intercomparison exercise (IAEA/SIE/01) for selected laboratories of the ALMERA network. The main objective of this exercise was to compare soil sampling procedures used by different participating laboratories. The performance evaluation results of the interlaboratory comparison exercises performed in the framework of

  6. 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.

  7. The Relationship between Multiple Substance Use, Perceived Academic Achievements, and Selected Socio-Demographic Factors in a Polish Adolescent Sample

    Science.gov (United States)

    Mazur, Joanna; Tabak, Izabela; Dzielska, Anna; Wąż, Krzysztof; Oblacińska, Anna

    2016-01-01

    Predictors of high-risk patterns of substance use are often analysed in relation to demographic and school-related factors. The interaction between these factors and the additional impact of family wealth are still new areas of research. The aim of this study was to find determinants of the most common patterns of psychoactive substance use in mid-adolescence, compared to non-users. A sample of 1202 Polish students (46.1% boys, mean age of 15.6 years) was surveyed in 2013/2014. Four patterns of psychoactive substance use were defined using cluster analysis: non-users—71.9%, mainly tobacco and alcohol users—13.7%, high alcohol and cannabis users—7.2%, poly-users—7.2%. The final model contained the main effects of gender and age, and one three-way (perceived academic achievement × gender × family affluence) interaction. Girls with poor perception of school performance (as compared to girls with better achievements) were at significantly higher risk of being poly-users, in both less and more affluent families (adjusted odds ratio (OR) = 5.55 and OR = 3.60, respectively). The impact of family affluence was revealed only in interaction with other factors. Patterns of substance use in mid-adolescence are strongly related to perceived academic achievements, and these interact with selected socio-demographic factors. PMID:28009806

  8. The Relationship between Multiple Substance Use, Perceived Academic Achievements, and Selected Socio-Demographic Factors in a Polish Adolescent Sample

    Directory of Open Access Journals (Sweden)

    Joanna Mazur

    2016-12-01

    Full Text Available Predictors of high-risk patterns of substance use are often analysed in relation to demographic and school-related factors. The interaction between these factors and the additional impact of family wealth are still new areas of research. The aim of this study was to find determinants of the most common patterns of psychoactive substance use in mid-adolescence, compared to non-users. A sample of 1202 Polish students (46.1% boys, mean age of 15.6 years was surveyed in 2013/2014. Four patterns of psychoactive substance use were defined using cluster analysis: non-users—71.9%, mainly tobacco and alcohol users—13.7%, high alcohol and cannabis users—7.2%, poly-users—7.2%. The final model contained the main effects of gender and age, and one three-way (perceived academic achievement × gender × family affluence interaction. Girls with poor perception of school performance (as compared to girls with better achievements were at significantly higher risk of being poly-users, in both less and more affluent families (adjusted odds ratio (OR = 5.55 and OR = 3.60, respectively. The impact of family affluence was revealed only in interaction with other factors. Patterns of substance use in mid-adolescence are strongly related to perceived academic achievements, and these interact with selected socio-demographic factors.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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...

  14. 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

  15. Analysing home-ownership of couples: the effect of selecting couples at the time of the survey.

    Science.gov (United States)

    Mulder, C H

    1996-09-01

    "The analysis of events encountered by couple and family households may suffer from sample selection bias when data are restricted to couples existing at the moment of interview. The paper discusses the effect of sample selection bias on event history analyses of buying a home [in the Netherlands] by comparing analyses performed on a sample of existing couples with analyses of a more complete sample including past as well as current partner relationships. The results show that, although home-buying in relationships that have ended differs clearly from behaviour in existing relationships, sample selection bias is not alarmingly large." (SUMMARY IN FRE) excerpt

  16. 40 CFR Appendix A to Subpart F of... - Sampling Plans for Selective Enforcement Auditing of Small Nonroad Engines

    Science.gov (United States)

    2010-07-01

    ... Enforcement Auditing of Small Nonroad Engines A Appendix A to Subpart F of Part 90 Protection of Environment...-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Selective Enforcement Auditing Pt. 90, Subpt. F, App. A Appendix A to Subpart F of Part 90—Sampling Plans for Selective Enforcement Auditing of Small Nonroad Engines...

  17. A survey on selection, use, maintenance, and management of chemical protective gloves at workplaces in Japan.

    Science.gov (United States)

    Kabe, Isamu; Tsuruoka, Hiroko; Kochi, Takeshi; Koga, Yasuo; Eguchi, Masafumi; Matsui, Tomomi; Ito, Rie; Tokujitani, Yoko; Miyauchi, Hiroyuki; Tanaka, Shigeru

    2017-10-05

    The aim of this study was to survey the selection, use, and maintenance of chemical protective gloves (CPGs) at real workplaces. Subjects comprised 817 workers using CPGs at seven domestic manufacturing plants in Japan. We administered an anonymous questionnaire survey comprising the following aspect related to CPGs: environment of use, conditions of use, method of selection, knowledge/awareness pertaining to their use, method of use, precautionary measures associated with their use, maximum time of use, and maintenance. We compared responses provided by management staff and field workers. Chi square test was used for the analysis. Respondents included 661 (80.9%) manufacturing workers, 121 (14.8%) managers or supervisors, and 35 (4.3%) others. In total, 70.5% organic solvents, 28.9% acid or/and alkali, 18.1% dust, and 10.3% carcinogenic substances were the chemical substances handled using CPGs. The reason for deciding to wear CPGs was "the use of chemical substances" for 46.5%, "notice in safety data sheet (SDS) " for 29.8%, and "management staffs' guidance" for 21.4% respondents. "The grasp of chemical substances" was 70.1% (91.1% excluding "not applicable" ). "Warning of caution on skin and eyes" was indicated by 69.5% (91.0%) and "educational reasons for use of CPGs" was accepted by 68.1% (90.7%) respondents. On the other hand, the rate of responses such as "obtaining permeability test results of target substances" and "mixed substances are selected considering substances with short permeation time" was 25.2% (38.4%) and 29.2% (48.4%), respectively. The rate of "yes" as a response in the item concerning "permeation test" was low. On comparing the response provided by the management staff and field workers, the rate of "the permeation test result of the target substance was obtained" was 27.7% for management staff and 41.2% for field workers (p = 0.022). Regarding the cuffs of CPGs, the rate of "to fold back and to prevent sagging" and "mounted with tape" were

  18. 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...

  19. 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.

  20. A field survey on parasites and antibodies against selected pathogens in owned dogs in Lilongwe, Malawi

    Directory of Open Access Journals (Sweden)

    Karin Alvåsen

    2016-07-01

    Full Text Available The aim of this study was to screen for selected parasites and antibody levels against vectorborne pathogens in owned dogs in Lilongwe, Malawi. The study population consisted of 100 dogs; 80 participating in vaccination–spaying campaigns and 20 visiting a veterinary clinic as paying clients. All dogs went through a general physical examination including visual examination for signs of ectoparasites. A total of 100 blood samples were analysed using commercial snap tests and 40 faecal samples by egg flotation in saturated sodium chloride. The sampled dogs had a seroprevalence of 12% for Anaplasma spp., 22% for Ehrlichia spp., 4% for Dirofilaria immitis and 1% for Leishmania spp. Eggs from Ancylostoma spp. were found in 80% of the faecal samples, whereas eggs of Trichuris vulpis, Toxocara canis and Toxascaris leonina were only present in 3%, 8% and 13% of the samples, respectively. Ectoparasites such as Ctenocephalides sp., Trichodectes sp. and ticks were present on 98%, 25% and 11%, respectively, of the campaign dogs. Among client dogs, 35% had Ctenocephalides fleas, 10% had Trichodectes lice and none had ticks. Public education and prophylactic treatment could be used to improve the animal welfare of dogs; this would most likely also have positive impact on public health.

  1. Gamma radiation measurement in select sand samples from Camburi beach - Vitoria, Espirito Santo, Brazil: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Livia F.; Pecequilo, Brigitte R.S.; Aquino, Reginaldo R., E-mail: lfbarros@ipen.b, E-mail: brigitte@ipen.b, E-mail: raquino@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The variation of natural radioactivity along the surface of the beach sands of Camburi, located in Vitoria, capital of Espirito Santo, southeastern Brazil, was determined from the contents of {sup 226}Ra, {sup 232}Th and {sup 40}K. Eleven collecting points was selected along all the 6 km extension of the Camburi beach. Sand samples collected from all established points on January 2011 were dried and sealed in standard 100 mL polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the {sup 238}U and {sup 232}Th series. The {sup 226}Ra concentration was determined from the weighted average concentrations of {sup 214}Pb and {sup 214}Bi. The {sup 232}Th concentration was determined from the weighted average concentrations of {sup 228}Ac, {sup 212}Pb and {sup 212}Bi and the {sup 40}K from its single gamma transition. Preliminary results show activity concentrations varying from 5 Bq.kg{sup -1} to {sup 222} Bq.kg{sup -1} for {sup 226}Ra and from 14 Bq.kg{sup -1} to 1074 Bq.kg{sup -'}1 for {sup 232}Th, both with the highest values for Camburi South and Central. For {sup 40}K, the activity concentrations ranged from 14 Bq.kg{sup -1} to 179 Bq.kg{sup -1} and the highest values were obtained for Camburi South. (author)

  2. Crude protein, fibre and phytic acid in vitro digestibility of selected legume and buckwheat samples

    Directory of Open Access Journals (Sweden)

    Petra Vojtíšková

    2013-01-01

    Full Text Available The aim of this study was to determine crude protein, fibre and phytic acid in vitro digestibility of selected legumes and buckwheat products. All analyses except the phytic acid contents were performed in the line with the Commission Regulation (EC No. 152/2009. A modified version of Holt’s Method was used for phytic acid (phytate determination. None of all samples contained more than 11% of moisture. Soybeans are rich in crude protein; they contain nearly 40% of this compound. The content of crude protein in buckwheat flours was about 14%. The highest amount of phytate was found in common beans and soybeans-about 2 g/100 g of dry matter. On the other hand, the lowest phytate content was observed in buckwheat pasta (F. esculentum groats was 1.9 g per 100 g of dry matter. In vitro digestibility was determined using an incubator Daisy and pepsin enzymes and the combination of pepsin and pancreatin. The highest coefficient of crude protein digestibility was discovered to be in peels and wholemeal flour. The greatest fibre digestibility coefficients were obtained for peels, which contain about 65% of fibre in their dry matter. When pepsin was used, a higher phytic acid digestibility coefficient for G. max, Ph. vulgaris, peels, flour, groats and broken groats was observed; while when the combination of pepsin and pancreatin was used, higher phytic acid digestibility coefficients for peas, lentil and wholemeal flour were observed.

  3. Gamma radiation measurement in select sand samples from Camburi beach - Vitoria, Espirito Santo, Brazil: preliminary results

    International Nuclear Information System (INIS)

    Barros, Livia F.; Pecequilo, Brigitte R.S.; Aquino, Reginaldo R.

    2011-01-01

    The variation of natural radioactivity along the surface of the beach sands of Camburi, located in Vitoria, capital of Espirito Santo, southeastern Brazil, was determined from the contents of 226 Ra, 232 Th and 40 K. Eleven collecting points was selected along all the 6 km extension of the Camburi beach. Sand samples collected from all established points on January 2011 were dried and sealed in standard 100 mL polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks ingrowth period, in order to allow the secular equilibrium in the 238 U and 232 Th series. The 226 Ra concentration was determined from the weighted average concentrations of 214 Pb and 214 Bi. The 232 Th concentration was determined from the weighted average concentrations of 228 Ac, 212 Pb and 212 Bi and the 40 K from its single gamma transition. Preliminary results show activity concentrations varying from 5 Bq.kg -1 to 222 Bq.kg -1 for 226 Ra and from 14 Bq.kg -1 to 1074 Bq.kg -' 1 for 232 Th, both with the highest values for Camburi South and Central. For 40 K, the activity concentrations ranged from 14 Bq.kg -1 to 179 Bq.kg -1 and the highest values were obtained for Camburi South. (author)

  4. Analysis of a selected sample of RR Lyrae stars in the LMC from OGLE-III

    International Nuclear Information System (INIS)

    Chen Bing-Qiu; Jiang Bi-Wei; Yang Ming

    2013-01-01

    A systematic study of RR Lyrae stars is performed using a selected sample of 655 objects in the Large Magellanic Cloud (LMC) with long-term observations and numerous measurements from the Optical Gravitational Lensing Experiment III project. The phase dispersion method and linear superposition of the harmonic oscillations are used to derive the pulsation frequency and properties of light variation. It is found that a dichotomy exists in Oosterhoff Type I and Oosterhoff Type II for RR Lyrae stars in the LMC. Due to our strict criteria for identifying a frequency, a lower limit for the incidence rate of Blazhko modulation in the LMC is estimated in various subclasses of RR Lyrae stars. For fundamental-mode RR Lyrae stars, the rate of 7.5% is smaller than the previous result. In the case of the first-overtone RR Lyrae variables, the rate of 9.1% is relatively high. In addition to the Blazhko variables, 15 objects are identified to pulsate in the fundamental/first-overtone double mode. Furthermore, four objects show a period ratio around 0.6, which makes them very likely to be rare pulsators in the fundamental/second-overtone double mode. (research papers)

  5. 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

  6. 40 CFR Appendix Xi to Part 86 - Sampling Plans for Selective Enforcement Auditing of Light-Duty Vehicles

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Sampling Plans for Selective Enforcement Auditing of Light-Duty Vehicles XI Appendix XI to Part 86 Protection of Environment ENVIRONMENTAL... Enforcement Auditing of Light-Duty Vehicles 40% AQL Table 1—Sampling Plan Code Letter Annual sales of...

  7. Survey and analysis of materials research and development at selected federal laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J.E.; Fink, C.R.

    1984-04-01

    This document presents the results of an effort to transfer existing, but relatively unknown, materials R and D from selected federal laboratories to industry. More specifically, recent materials-related work at seven federal laboratories potentially applicable to improving process energy efficiency and overall productiviy in six energy-intensive manufacturing industries was evaluated, catalogued, and distributed to industry representatives to gauge their reaction. Laboratories surveyed include: Air Force Wright Aeronautical Laboratories Material Laboratory (AFWAL). Pacific Northwest Laboratory (PNL), National Aeronautics and Space Administration Marshall Flight Center (NASA Marshall), Oak Ridge National Laboratory (ORNL), Brookhaven National Laboratory (BNL), Idaho National Engineering Laboratory (INEL), and Jet Propulsion Laboratory (JPL). Industries included in the effort are: aluminum, cement, paper and allied products, petroleum, steel and textiles.

  8. An HI selected sample of galaxies : The HI mass function and the surface brightness distribution

    NARCIS (Netherlands)

    Zwaan, M; Briggs, F; Sprayberry, D

    Results from the Arecibo HI Strip Survey, an unbiased extragalactic HI survey, combined with optical and 21 cm follow-up observations, determine the HI mass function and the cosmological mass density of HI at the present epoch. Both are consistent with earlier estimates, computed for the population

  9. 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.

  10. Survey of siting practices for selected management projects in seven countries

    International Nuclear Information System (INIS)

    Hardin, E.; Aahagen, H.

    1992-06-01

    This paper surveys siting practices for deep geologic disposal in seven countries, and attempts to formulate generalizations which could be useful for the upcoming review of the Swedish plan for siting the SFL repository (R and D 92). Comparison of projects in different countries is done with full appreciation of the technical, legal, and cultural differences. The seven countries were selected for experience with siting in crystalline rock, similarity of siting practices to Sweden, and the availability of published information. Local governments have demonstrated effective veto power in each of the seven countries surveyed, although this power is exercised in different ways. This paper shows how the siting strategy itself affects the ability and the inclination of localities to block the project. It shows by example that public involvement, parallel vs. sequential characterization, schedule for siting activities, and the existence of interim waste storage capability have an impact on the success of siting. The focus of this paper is deep geologic disposal. Shallow land disposal and non-radioactive wastes are not discussed in detail, with three exceptions: LLW disposal siting in the U.S. and Canada, and the SAKAB incinerator projects in Sweden. These provide insight into siting approaches and demonstrate that conclusions regarding deep geologic disposal are supported by other experience. (114 refs.) (au)

  11. Serologic survey for selected arboviruses and other potential pathogens in wildlife from Mexico.

    Science.gov (United States)

    Aguirre, A A; McLean, R G; Cook, R S; Quan, T J

    1992-07-01

    During 1988 and 1989, a serologic survey of wildlife was conducted in northeastern Mexico to determine the presence, prevalence, and distribution of arboviruses and other selected disease agents. Eighty mammal specimens were tested. Antibodies to vesicular stomatitis-Indiana, Venezuelan equine encephalitis-Mena II, Rio Grande virus, and vesicular stomatitis-New Jersey were detected predominantly in small mammals. Deer and mouflon (Ovis musimon) had antibodies to bluetongue and epizootic hemorrhagic disease. Two species had serologic evidence of recent exposure to Francisella tularensis. A white-tailed deer (Odocoileus virginianus) had antibodies to Anaplasma marginale. All specimens tested for antibodies against Yersinia pestis and Brucella abortus were negative. Sera from 315 birds were tested for antibody against five equine encephalitis viruses and six avian pathogens. During 1988, antibodies to Venezuelan equine encephalitis-Mena II, Venezuelan equine encephalitis-TC83, St. Louis encephalitis, eastern equine encephalitis, and western equine encephalitis were detected in birds of several species. Antibodies to Pasteurella multocida and Newcastle disease virus were also detected. Birds from five species presented antibodies to Mycoplasma meleagridis. Specimens tested for M. gallisepticum, M. synoviae, and Chlamydia psittaci were negative. To the best of our knowledge, this survey represents the first serologic evidence of bluetongue, Cache Valley virus, epizootic hemorrhagic disease, Jamestown Canyon virus, vesicular stomatitis-Indiana, vesicular stomatitis-New Jersey, Rio Grande virus, and tularemia reported among wildlife in Mexico.

  12. Report on the Survey on Regulation of Site Selection and Preparation

    International Nuclear Information System (INIS)

    Webster, Philip

    2010-01-01

    At its first meeting in May 2008, the Working Group discussed a task to 'Prepare a report reviewing the various practices used by regulators in the regulation of nuclear power plant siting. The report should consider regulator practices on sites where a mixture of activities are taking place (e.g. operating units, new construction, decommissioning, etc) including organization of the regulators organisation, methods, systems, etc.'. Following discussion, the Working Group assigned an Action 1-5 to 'develop a survey on the regulation of nuclear sites including seismicity issues, security issues, multi-units aspects and regulator practices on sites where a mixture of activities are taking place (e.g. operating units, new construction, decommissioning, etc.)'. The Survey was prepared and issued by the NEA in July 2008 with a request to the member states to provide their responses by the next meeting of the Working Group in October 2008. In addition to addressing the specific topics actioned by the Working Group, the Survey also investigated the broader context of siting, in order to address the Mandate that had been approved by the CNRA. The questions in the survey therefore covered the topics of site evaluation, site selection, regulatory approval, site preparation and regulatory oversight. A topic of particular interest was to what extent IAEA guidance on site evaluation was followed. The survey considered the possibility that a body other than the safety regulator may approve the choice of site or permit the applicant to start to prepare it. The survey also investigated the existence of formal requirements and informal expectations, recognizing that these both form part of the regulatory tool-kit. Responses were received from all twelve member states that were then members of the Working Group. The responses were reviewed at the second meeting of the Working Group in October 2008. In general, it could be stated that new reactors are licensed in

  13. Molecularly imprinted membrane extraction combined with high-performance liquid chromatography for selective analysis of cloxacillin from shrimp samples.

    Science.gov (United States)

    Du, Wei; Sun, Min; Guo, Pengqi; Chang, Chun; Fu, Qiang

    2018-09-01

    Nowadays, the abuse of antibiotics in aquaculture has generated considerable problems for food safety. Therefore, it is imperative to develop a simple and selective method for monitoring illegal use of antibiotics in aquatic products. In this study, a method combined molecularly imprinted membranes (MIMs) extraction and liquid chromatography was developed for the selective analysis of cloxacillin from shrimp samples. The MIMs was synthesized by UV photopolymerization, and characterized by scanning electron microscope, Fourier transform infrared spectra, thermo-gravimetric analysis and swelling test. The results showed that the MIMs exhibited excellent permselectivity, high adsorption capacity and fast adsorption rate for cloxacillin. Finally, the method was utilized to determine cloxacillin from shrimp samples, with good accuracies and acceptable relative standard deviation values for precision. The proposed method was a promising alternative for selective analysis of cloxacillin in shrimp samples, due to the easy-operation and excellent selectivity. Copyright © 2018. Published by Elsevier Ltd.

  14. THE HOST GALAXY PROPERTIES OF VARIABILITY SELECTED AGN IN THE PAN-STARRS1 MEDIUM DEEP SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Heinis, S.; Gezari, S.; Kumar, S. [Department of Astronomy, University of Maryland, College Park, MD (United States); Burgett, W. S.; Flewelling, H.; Huber, M. E.; Kaiser, N.; Wainscoat, R. J.; Waters, C. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2016-07-20

    We study the properties of 975 active galactic nuclei (AGNs) selected by variability in the Pan-STARRS1 Medium deep Survey. Using complementary multi-wavelength data from the ultraviolet to the far-infrared, we use spectral energy distribution fitting to determine the AGN and host properties at z < 1 and compare to a well-matched control sample. We confirm the trend previously observed: that the variability amplitude decreases with AGN luminosity, but we also observe that the slope of this relation steepens with wavelength, resulting in a “redder when brighter” trend at low luminosities. Our results show that AGNs are hosted by more massive hosts than control sample galaxies, while the rest frame dust-corrected NUV r color distribution of AGN hosts is similar to control galaxies. We find a positive correlation between the AGN luminosity and star formation rate (SFR), independent of redshift. AGN hosts populate the entire range of SFRs within and outside of the Main Sequence of star-forming galaxies. Comparing the distribution of AGN hosts and control galaxies, we show that AGN hosts are less likely to be hosted by quiescent galaxies and more likely to be hosted by Main Sequence or starburst galaxies.

  15. 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

  16. Detailed geochemical survey for east-central Minnesota, geology and geochemistry of selected uranium targets

    International Nuclear Information System (INIS)

    Morey, G.B.; Lively, R.S.

    1980-01-01

    Results of a detailed geochemical survey of approximately 6820 km 2 in parts of Aitkin, Carlton, Kanabec, and Pine Counties, east-central Minnesota are reported. Geochemical data are presented for 883 groundwater samples and 200 bedrock samples. Although all of the groundwaters in the study area have similar major-element concentrations and therefore presumably a common ancestry, small differences in the minor-element concentrations serve to characterize various aquifers, both in the Quaternary deposits and in the bedrock. All of the aquifers locally yield waters having statistically anomalous concentrations of uranium or radon, but these anomalies are spatially coincident only in a few places and particularly in three geologic environments considered favorable for uranium mineralization. These include the following: (1) Thomson Formation near the unconformably overlying Fond du Lac Formation, (2) Hinckley Sandstone near a major fault system, and (3) Denham Formation near the unconformity with the McGrath Gneiss, particularly where these rocks are faulted and overlain by the Fond du Lac Formation. One additional uranium environment characterized by thin laminae of uraniferous apatite was located in the Thomson Formation during outcrop reconnaissance and sampling. The coincidence of this and other anomalously high uranium values in the bedrock with specific uranium and radon anomalies in the groundwater confirms the usefulness of the hydrogeochemical data to uranium exploration in this glaciated terrane

  17. 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,

  18. Chemical and X-ray diffraction analysis on selected samples from the TMI-2 reactor core

    International Nuclear Information System (INIS)

    Kleykamp, H.; Pejsa, R.

    1991-05-01

    Selected samples from different positions of the damaged TMI-2 reactor core were investigated by X-ray microanalysis and X-ray diffraction. The measurements yield the following resolidified phases after cooling: Cd and In depleted Ag absorber material, intermetallic Zr-steel compounds, fully oxidized Zircaloy, UO 2 -ZrO 2 solid solutions and their decomposed phases, and Fe-Al-Cr-Zr spinels. The composition of the phases and their lattice parameters as well as the eutectic and monotectic character can serve as indicators of local temperatures of the core. The reaction sequences are estimated from the heterogeneous equilibria of these phases. The main conclusions are: (1) Liquefaction onset is locally possible by Inconel-Zircaloy and steel-Zircaloy reactions of spacers and absorber guide tubes at 930deg C. However, increased rates of dissolution occur above 1200deg C. (2) UO 2 dissolution in the Inconel-steel-Zircaloy melt starts at 1300deg C with increased rates above 1900deg C. (3) Fuel temperatures in the core centre are increased above 2550deg C, liquid (U,Zr)O 2 is generated. (4) Square UO 2 particles are reprecipitated from the Incoloy-steel-Zircaloy-UO 2 melt during cooling, the remaining metallic melt is oxygen poor; two types of intermetallic phases are formed. (5) Oxidized Fe and Zr and Al 2 O 3 from burnable absorber react to spinels which form a low melting eutectic with the fuel at 1500deg C. The spinel acts as lubricant for fuel transport to the lower reactor plenum above 1500deg C. (6) Ruthenium (Ru-106) is dissolved in the steel phase, antimony (Sb-125) in the α-Ag absorber during liquefaction. (7) Oxidation of the Zircaloy-steel phases takes place mainly in the reflood stage 3 of the accident scenario. (orig.) [de

  19. Investigation of selected trace elements in hair samples of eczema patients

    International Nuclear Information System (INIS)

    Osman, N. O.

    2010-12-01

    The aim of this case-control study was to investigate the relationship between selected trace elements and skin diseases, namely eczema. Fifty five patients affected by the most frequent eczema types were recruited at the onset of disease at the hospital of dermatology in Khartoum together with thirty healthy controls. Fe, Zn, Cu, and Ni were measured in hair samples obtained from both patients and control group using Atomic Absorption Spectrometry (AAS). Data analysis was performed using the T-test. Partial correlation was used to study the relationship between the elemental concentration. Certified reference material (IAEA-85) Hair Powder) produced by the International Atomic Energy Agency (IAEA) was used as a quality control to check the accuracy and precision of the analytical technique, good agreement was achieved for all elements under investigation. Significant variations (p<0.05) in the concentrations of Fe, Zn, Cu, and Ni in the hair of the patients compared to the control group, and this difference was a decrease of iron, zinc and copper, therefore, should be given to the patient doses of these elements, while there was an increase in the nickel. So it is not included in the treatment. These interesting associations between the levels the of trace elements could be used as an indication for the disease as well as to monitor the treatment. Comparisons of the results obtained in the present study with those conducted for other population in the literature showed very close agreement. The levels of the elements under investigation are comparable with the data obtained from the literature for other populations with exception of Fe which was found to be very high in Sudanese population. (Author)

  20. Electron microprobe analyses of selected samples from deep rock disposal experiment No. 1

    International Nuclear Information System (INIS)

    Hlava, P.F.; Chambers, W.F.

    1976-04-01

    Deep Rock Disposal Experiment No. 1 was designed to provide information about the interaction between a molten, glass-based, nuclear waste simulant and rock material. Selected samples from this experiment were examined by optical microscopy and electron probe microanalysis. Analysis of the homogenized material in the convection cell that was created in the central portion of the melt region shows that an amount of rock equal to about one-half of the original amount of waste simulant was incorporated in the melt during the experiment. Stagnant melt at the sides of the cell formed a glass with large compositional gradients. A white band separated the convected and stagnant materials. The color of the band is attributed to light scattering by small crystallites formed during cooling. Four types of crystallites grew from the melt: two oxides, a Mg--Fe borate, and a silicate. Spinel (MgO, Cr 2 O 3 , FeO (Fe 2 O 3 ), and NiO) was the most common crystallite in the glass. The spinel crystallites found within the convection cell displayed skeletal morphology and oscillatory zoning which indicates growth at varying temperatures as they were carried along by convection. A single cluster of nonskeletal (Fe,Cr) 2 O 3 crystallites was found at the bottom of the melt zone where convection did not occur. Mg--Fe borate crystallites grew in clusters in the central portion of the convection cell after convection ceased. A silicate similar to Fe-rich diopside (CaMgSi 2 O 6 ) with unusual amounts of Ce 2 O 3 and other heavy metal oxides formed as larger crystallites in the stagnant melt at the side of the convection cell and as many very small crystallites in the white band

  1. Investigation of selected trace elements in hair samples of eczema patients

    Energy Technology Data Exchange (ETDEWEB)

    Osman, N O [Atomic Energy Council, Sudan Academy of Sciences (SAS), Khartoum (Sudan)

    2010-12-15

    The aim of this case-control study was to investigate the relationship between selected trace elements and skin diseases, namely eczema. Fifty five patients affected by the most frequent eczema types were recruited at the onset of disease at the hospital of dermatology in Khartoum together with thirty healthy controls. Fe, Zn, Cu, and Ni were measured in hair samples obtained from both patients and control group using Atomic Absorption Spectrometry (AAS). Data analysis was performed using the T-test. Partial correlation was used to study the relationship between the elemental concentration. Certified reference material (IAEA-85) Hair Powder) produced by the International Atomic Energy Agency (IAEA) was used as a quality control to check the accuracy and precision of the analytical technique, good agreement was achieved for all elements under investigation. Significant variations (p<0.05) in the concentrations of Fe, Zn, Cu, and Ni in the hair of the patients compared to the control group, and this difference was a decrease of iron, zinc and copper, therefore, should be given to the patient doses of these elements, while there was an increase in the nickel. So it is not included in the treatment. These interesting associations between the levels the of trace elements could be used as an indication for the disease as well as to monitor the treatment. Comparisons of the results obtained in the present study with those conducted for other population in the literature showed very close agreement. The levels of the elements under investigation are comparable with the data obtained from the literature for other populations with exception of Fe which was found to be very high in Sudanese population. (Author)

  2. 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.

  3. 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.

  4. 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

  5. Re-Emergence of Under-Selected Stimuli, after the Extinction of Over-Selected Stimuli in an Automated Match to Samples Procedure

    Science.gov (United States)

    Broomfield, Laura; McHugh, Louise; Reed, Phil

    2008-01-01

    Stimulus over-selectivity occurs when one of potentially many aspects of the environment comes to control behaviour. In two experiments, adults with no developmental disabilities, were trained and tested in an automated match to samples (MTS) paradigm. In Experiment 1, participants completed two conditions, in one of which the over-selected…

  6. Towards the harmonization between National Forest Inventory and Forest Condition Monitoring. Consistency of plot allocation and effect of tree selection methods on sample statistics in Italy.

    Science.gov (United States)

    Gasparini, Patrizia; Di Cosmo, Lucio; Cenni, Enrico; Pompei, Enrico; Ferretti, Marco

    2013-07-01

    In the frame of a process aiming at harmonizing National Forest Inventory (NFI) and ICP Forests Level I Forest Condition Monitoring (FCM) in Italy, we investigated (a) the long-term consistency between FCM sample points (a subsample of the first NFI, 1985, NFI_1) and recent forest area estimates (after the second NFI, 2005, NFI_2) and (b) the effect of tree selection method (tree-based or plot-based) on sample composition and defoliation statistics. The two investigations were carried out on 261 and 252 FCM sites, respectively. Results show that some individual forest categories (larch and stone pine, Norway spruce, other coniferous, beech, temperate oaks and cork oak forests) are over-represented and others (hornbeam and hophornbeam, other deciduous broadleaved and holm oak forests) are under-represented in the FCM sample. This is probably due to a change in forest cover, which has increased by 1,559,200 ha from 1985 to 2005. In case of shift from a tree-based to a plot-based selection method, 3,130 (46.7%) of the original 6,703 sample trees will be abandoned, and 1,473 new trees will be selected. The balance between exclusion of former sample trees and inclusion of new ones will be particularly unfavourable for conifers (with only 16.4% of excluded trees replaced by new ones) and less for deciduous broadleaves (with 63.5% of excluded trees replaced). The total number of tree species surveyed will not be impacted, while the number of trees per species will, and the resulting (plot-based) sample composition will have a much larger frequency of deciduous broadleaved trees. The newly selected trees have-in general-smaller diameter at breast height (DBH) and defoliation scores. Given the larger rate of turnover, the deciduous broadleaved part of the sample will be more impacted. Our results suggest that both a revision of FCM network to account for forest area change and a plot-based approach to permit statistical inference and avoid bias in the tree sample

  7. 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

  8. 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…

  9. The VISTA Carina Nebula Survey. II. Spatial distribution of the infrared-excess-selected young stellar population

    Science.gov (United States)

    Zeidler, P.; Preibisch, T.; Ratzka, T.; Roccatagliata, V.; Petr-Gotzens, M. G.

    2016-01-01

    We performed a deep wide-field (6.76 sq. deg) near-infrared survey with the VISTA telescope that covers the entire extent of the Carina nebula complex (CNC). The point-source catalog created from these data contains around four million individual objects down to masses of 0.1 M⊙. We present a statistical study of the large-scale spatial distribution and an investigation of the clustering properties of infrared-excesses objects, which are used to trace disk-bearing young stellar objects (YSOs). A selection based on a near-infrared (J-H) versus (H-Ks) color-color diagram shows an almost uniform distribution over the entire observed area. We interpret this as a result of the very high degree of background contamination that arises from the Carina Nebula's location close to the Galactic plane. Complementing the VISTA near-infrared catalog with Spitzer IRAC mid-infrared photometry improves the situation of the background contamination considerably. We find that a (J-H) versus (Ks- [4.5]) color-color diagram is well suited to tracing the population of YSO-candidates (cYSOs) by their infrared excess. We identify 8781 sources with strong infrared excess, which we consider as cYSOs. This sample is used to investigate the spatial distribution of the cYSOs with a nearest-neighbor analysis. The surface density distribution of cYSOs agrees well with the shape of the clouds as seen in our Herschel far-infrared survey. The strong decline in the surface density of excess sources outside the area of the clouds supports the hypothesis that our excess-selected sample consists predominantly of cYSOs with a low level of background contamination. This analysis allows us to identify 14 groups of cYSOs outside the central area.Our results suggest that the total population of cYSOs in the CNC comprises about 164 000 objects, with a substantial fraction (~35%) located in the northern, still not well studied parts. Our cluster analysis suggests that roughly half of the cYSOs constitute a

  10. Mineralogy, petrology and whole-rock chemistry data compilation for selected samples of Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Connolly, J.R.

    1991-12-01

    Petrologic, bulk chemical, and mineralogic data are presented for 49 samples of tuffaceous rocks from core holes USW G-1 and UE-25a number-sign 1 at Yucca Mountain, Nevada. Included, in descending stratigraphic order, are 11 samples from the Topopah Spring Member of the Paintbrush Tuff, 12 samples from the Tuffaceous Beds of Calico Hills, 3 samples from the Prow Pass Member of the Crater Flat Tuff, 20 samples from the Bullfrog Member of the Crater Flat Tuff and 3 samples from the Tram Member of the Crater Flat Tuff. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data vary considerably between groups of samples, and include thin section descriptions (some with modal analyses for which uncertainties are estimated), electron microprobe analyses of mineral phases and matrix, mineral identifications by X-ray diffraction, and major element analyses with uncertainty estimates

  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. Income Expectations of University Students: Sample of Selected Economic Universities in the Czech Republic, England and Poland

    Directory of Open Access Journals (Sweden)

    Kateřina Maršíková

    2012-12-01

    Full Text Available The objective of the paper is to analyze students’ perceptions and expectations of their future incomes. By doing so, authors bring a possible quantitative argument about the rate of return of investment into higher education based on data from selected economic universities, and thus open space for discussion about financing of Czech public universities from public or private sources. The authors used data from a large survey among students of selected faculties of economics and compared the results from Czech, Polish and English respondents. All the performed tests have indicated and identified one critical finding that confirmed results of previous surveys:the value of the spot expected rates of return on investment to tertiary education for the Czech Republic never falls below 8.45 per cent, even when allowed for gender of respondents, knowledge about income of respondents’ friends, or level of education of respondents’ parents.

  13. A quantitative method to detect explosives and selected semivolatiles in soil samples by Fourier transform infrared spectroscopy

    International Nuclear Information System (INIS)

    Clapper-Gowdy, M.; Dermirgian, J.; Robitaille, G.

    1995-01-01

    This paper describes a novel Fourier transform infrared (FTIR) spectroscopic method that can be used to rapidly screen soil samples from potentially hazardous waste sites. Samples are heated in a thermal desorption unit and the resultant vapors are collected and analyzed in a long-path gas cell mounted in a FTIR. Laboratory analysis of a soil sample by FTIR takes approximately 10 minutes. This method has been developed to identify and quantify microgram concentrations of explosives in soil samples and is directly applicable to the detection of selected volatile organics, semivolatile organics, and pesticides

  14. Determination of selected metals in coal samples from Lafia-Obi and ...

    African Journals Online (AJOL)

    coal samples were determined using atomic absorption spectroscopy (AAS). All the samples have comparable chromium and copper contents, while iron, aluminum, magnesium and potassium content vary to some extent. Metals concentrations in both Lafia-Obi and Chikila coal samples are within the limits allowed by the ...

  15. A PCR-based survey of selected Babesia and Theileria parasites in cattle in Sri Lanka.

    Science.gov (United States)

    Sivakumar, Thillaiampalam; Kothalawala, Hemal; Abeyratne, Sembukutti Arachchige Eranga; Vimalakumar, Singarayar Caniciyas; Meewewa, Asela Sanjeewa; Hadirampela, Dilhani Thilanka; Puvirajan, Thamotharampillai; Sukumar, Subramaniyam; Kuleswarakumar, Kulanayagam; Chandrasiri, Alawattage Don Nimal; Igarashi, Ikuo; Yokoyama, Naoaki

    2012-11-23

    Hemoprotozoan parasites are responsible for significant economic losses in cattle. We screened Sri Lankan cattle populations for the presence of Babesia bovis, Babesia bigemina, Theileria annulata, and Theileria orientalis, using species-specific PCR assays. Out of 316 samples collected from animals in four different districts of Sri Lanka (Nuwara Eliya, Polonnaruwa, Ampara, and Jaffna), 231 (73.1%) were positive for at least one parasite species. All four parasite species were detected among the study groups from all of the districts surveyed. The first and second commonest hemoprotozoan parasites identified were T. orientalis (53.5%) and B. bigemina (30.1%), respectively. We found that the dry zones (Polonnaruwa, Ampara, and Jaffna) had more Babesia-positive animals than the hill country wet zone (Nuwara Eliya). In contrast, T. orientalis was the predominant species detected in Nuwara Eliya, while infection with T. annulata was more common in the dry zones. In addition, 81 (35.1%) of the 231 positive samples were infected with more than one parasite species. The presence of multiple parasite species among the different cattle populations is of clinical and economic significance. Therefore, island-wide control and prevention programs against bovine babesiosis and theileriosis are needed to minimize the financial burden caused by these parasites. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. 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'…

  17. DNA barcoding of selected UAE medicinal plant species: a comparative assessment of herbarium and fresh samples.

    Science.gov (United States)

    Enan, Mohamed Rizk; Palakkott, Abdul Rasheed; Ksiksi, Taoufik Saleh

    2017-01-01

    It is commonly difficult to extract and amplify DNA from herbarium samples as they are old and preserved using different compounds. In addition, such samples are subjected to the accumulation of intrinsically produced plant substances over long periods (up to hundreds of years). DNA extraction from desert flora may pause added difficulties as many contain high levels of secondary metabolites. Herbarium samples from the Biology Department (UAE University) plant collection and fresh plant samples, collected from around Al-Ain (UAE), were used in this study. The three barcode loci for the coding genes matK, rbcL and rpoC1-were amplified. Our results showed that T. terresteris , H. robustum , T. pentandrus and Z. qatarense were amplified using all three primers for both fresh and herbaium samples. Both fresh and herbarium samples of C. comosum , however, were not amplified at all, using the three primers. Herbarium samples from A. javanica , C. imbricatum , T. aucherana and Z. simplex were not amplified with any of the three primers. For fresh samples 90, 90 and 80% of the samples were amplified using matK, rbcL and rpoC1, respectively. In short, fresh samples were significantly better amplified than those from herbarium sources, using the three primers. Both fresh and herbarium samples from one species ( C. comosum ), however, were not successfully amplified. It is also concluded that the rbcL regions showed real potentials to distinguish the UAE species under investigation into the appropriate family and genus.

  18. Selection bias in population-based cancer case-control studies due to incomplete sampling frame coverage.

    Science.gov (United States)

    Walsh, Matthew C; Trentham-Dietz, Amy; Gangnon, Ronald E; Nieto, F Javier; Newcomb, Polly A; Palta, Mari

    2012-06-01

    Increasing numbers of individuals are choosing to opt out of population-based sampling frames due to privacy concerns. This is especially a problem in the selection of controls for case-control studies, as the cases often arise from relatively complete population-based registries, whereas control selection requires a sampling frame. If opt out is also related to risk factors, bias can arise. We linked breast cancer cases who reported having a valid driver's license from the 2004-2008 Wisconsin women's health study (N = 2,988) with a master list of licensed drivers from the Wisconsin Department of Transportation (WDOT). This master list excludes Wisconsin drivers that requested their information not be sold by the state. Multivariate-adjusted selection probability ratios (SPR) were calculated to estimate potential bias when using this driver's license sampling frame to select controls. A total of 962 cases (32%) had opted out of the WDOT sampling frame. Cases age <40 (SPR = 0.90), income either unreported (SPR = 0.89) or greater than $50,000 (SPR = 0.94), lower parity (SPR = 0.96 per one-child decrease), and hormone use (SPR = 0.93) were significantly less likely to be covered by the WDOT sampling frame (α = 0.05 level). Our results indicate the potential for selection bias due to differential opt out between various demographic and behavioral subgroups of controls. As selection bias may differ by exposure and study base, the assessment of potential bias needs to be ongoing. SPRs can be used to predict the direction of bias when cases and controls stem from different sampling frames in population-based case-control studies.

  19. Microbiological sampling plan based on risk classification to verify supplier selection and production of served meals in food service operation.

    Science.gov (United States)

    Lahou, Evy; Jacxsens, Liesbeth; Van Landeghem, Filip; Uyttendaele, Mieke

    2014-08-01

    Food service operations are confronted with a diverse range of raw materials and served meals. The implementation of a microbial sampling plan in the framework of verification of suppliers and their own production process (functionality of their prerequisite and HACCP program), demands selection of food products and sampling frequencies. However, these are often selected without a well described scientifically underpinned sampling plan. Therefore, an approach on how to set-up a focused sampling plan, enabled by a microbial risk categorization of food products, for both incoming raw materials and meals served to the consumers is presented. The sampling plan was implemented as a case study during a one-year period in an institutional food service operation to test the feasibility of the chosen approach. This resulted in 123 samples of raw materials and 87 samples of meal servings (focused on high risk categorized food products) which were analyzed for spoilage bacteria, hygiene indicators and food borne pathogens. Although sampling plans are intrinsically limited in assessing the quality and safety of sampled foods, it was shown to be useful to reveal major non-compliances and opportunities to improve the food safety management system in place. Points of attention deduced in the case study were control of Listeria monocytogenes in raw meat spread and raw fish as well as overall microbial quality of served sandwiches and salads. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. 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