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Sample records for random representative sample

  1. Assessing sample representativeness in randomized controlled trials: application to the National Institute of Drug Abuse Clinical Trials Network.

    Science.gov (United States)

    Susukida, Ryoko; Crum, Rosa M; Stuart, Elizabeth A; Ebnesajjad, Cyrus; Mojtabai, Ramin

    2016-07-01

    To compare the characteristics of individuals participating in randomized controlled trials (RCTs) of treatments of substance use disorder (SUD) with individuals receiving treatment in usual care settings, and to provide a summary quantitative measure of differences between characteristics of these two groups of individuals using propensity score methods. Design Analyses using data from RCT samples from the National Institute of Drug Abuse Clinical Trials Network (CTN) and target populations of patients drawn from the Treatment Episodes Data Set-Admissions (TEDS-A). Settings Multiple clinical trial sites and nation-wide usual SUD treatment settings in the United States. A total of 3592 individuals from 10 CTN samples and 1 602 226 individuals selected from TEDS-A between 2001 and 2009. Measurements The propensity scores for enrolling in the RCTs were computed based on the following nine observable characteristics: sex, race/ethnicity, age, education, employment status, marital status, admission to treatment through criminal justice, intravenous drug use and the number of prior treatments. Findings The proportion of those with ≥ 12 years of education and the proportion of those who had full-time jobs were significantly higher among RCT samples than among target populations (in seven and nine trials, respectively, at P difference in the mean propensity scores between the RCTs and the target population was 1.54 standard deviations and was statistically significant at P different from individuals receiving treatment in usual care settings. Notably, RCT participants tend to have more years of education and a greater likelihood of full-time work compared with people receiving care in usual care settings. © 2016 Society for the Study of Addiction.

  2. Representative process sampling - in practice

    DEFF Research Database (Denmark)

    Esbensen, Kim; Friis-Pedersen, Hans Henrik; Julius, Lars Petersen

    2007-01-01

    Didactic data sets representing a range of real-world processes are used to illustrate "how to do" representative process sampling and process characterisation. The selected process data lead to diverse variogram expressions with different systematics (no range vs. important ranges; trends and....../or periodicity; different nugget effects and process variations ranging from less than one lag to full variogram lag). Variogram data analysis leads to a fundamental decomposition into 0-D sampling vs. 1-D process variances, based on the three principal variogram parameters: range, sill and nugget effect...

  3. Representative mass reduction in sampling

    DEFF Research Database (Denmark)

    Petersen, Lars; Esbensen, Harry Kim; Dahl, Casper Kierulf

    2004-01-01

    We here present a comprehensive survey of current mass reduction principles and hardware available in the current market. We conduct a rigorous comparison study of the performance of 17 field and/or laboratory instruments or methods which are quantitatively characterized (and ranked) for accuracy...... dividers, the Boerner Divider, the ??spoon method??, alternate/fractional shoveling and grab sampling. Only devices based on riffle splitting principles (static or rotational) passes the ultimate representativity test (with minor, but significant relative differences). Grab sampling, the overwhelmingly...... most often used mass reduction method, performs appallingly?its use must be discontinued (with the singular exception for completely homogenized fine powders). Only proper mass reduction (i.e. carried out in complete compliance with all appropriate design principles, maintenance and cleaning rules) can...

  4. Reserves Represented by Random Walks

    International Nuclear Information System (INIS)

    Filipe, J A; Ferreira, M A M; Andrade, M

    2012-01-01

    The reserves problem is studied through models based on Random Walks. Random walks are a classical particular case in the analysis of stochastic processes. They do not appear only to study reserves evolution models. They are also used to build more complex systems and as analysis instruments, in a theoretical feature, of other kind of systems. In this work by studying the reserves, the main objective is to see and guarantee that pensions funds get sustainable. Being the use of these models considering this goal a classical approach in the study of pensions funds, this work concluded about the problematic of reserves. A concrete example is presented.

  5. Employing a Multi-level Approach to Recruit a Representative Sample of Women with Recent Gestational Diabetes Mellitus into a Randomized Lifestyle Intervention Trial.

    Science.gov (United States)

    Nicklas, Jacinda M; Skurnik, Geraldine; Zera, Chloe A; Reforma, Liberty G; Levkoff, Sue E; Seely, Ellen W

    2016-02-01

    The postpartum period is a window of opportunity for diabetes prevention in women with recent gestational diabetes (GDM), but recruitment for clinical trials during this period of life is a major challenge. We adapted a social-ecologic model to develop a multi-level recruitment strategy at the macro (high or institutional level), meso (mid or provider level), and micro (individual) levels. Our goal was to recruit 100 women with recent GDM into the Balance after Baby randomized controlled trial over a 17-month period. Participants were asked to attend three in-person study visits at 6 weeks, 6, and 12 months postpartum. They were randomized into a control arm or a web-based intervention arm at the end of the baseline visit at six weeks postpartum. At the end of the recruitment period, we compared population characteristics of our enrolled subjects to the entire population of women with GDM delivering at Brigham and Women's Hospital (BWH). We successfully recruited 107 of 156 (69 %) women assessed for eligibility, with the majority (92) recruited during pregnancy at a mean 30 (SD ± 5) weeks of gestation, and 15 recruited postpartum, at a mean 2 (SD ± 3) weeks postpartum. 78 subjects attended the initial baseline visit, and 75 subjects were randomized into the trial at a mean 7 (SD ± 2) weeks postpartum. The recruited subjects were similar in age and race/ethnicity to the total population of 538 GDM deliveries at BWH over the 17-month recruitment period. Our multilevel approach allowed us to successfully meet our recruitment goal and recruit a representative sample of women with recent GDM. We believe that our most successful strategies included using a dedicated in-person recruiter, integrating recruitment into clinical flow, allowing for flexibility in recruitment, minimizing barriers to participation, and using an opt-out strategy with providers. Although the majority of women were recruited while pregnant, women recruited in the early postpartum period were

  6. Verification of Representative Sampling in RI waste

    International Nuclear Information System (INIS)

    Ahn, Hong Joo; Song, Byung Cheul; Sohn, Se Cheul; Song, Kyu Seok; Jee, Kwang Yong; Choi, Kwang Seop

    2009-01-01

    For evaluating the radionuclide inventories for RI wastes, representative sampling is one of the most important parts in the process of radiochemical assay. Sampling to characterized RI waste conditions typically has been based on judgment or convenience sampling of individual or groups. However, it is difficult to get a sample representatively among the numerous drums. In addition, RI waste drums might be classified into heterogeneous wastes because they have a content of cotton, glass, vinyl, gloves, etc. In order to get the representative samples, the sample to be analyzed must be collected from selected every drum. Considering the expense and time of analysis, however, the number of sample has to be minimized. In this study, RI waste drums were classified by the various conditions of the half-life, surface dose, acceptance date, waste form, generator, etc. A sample for radiochemical assay was obtained through mixing samples of each drum. The sample has to be prepared for radiochemical assay and although the sample should be reasonably uniform, it is rare that a completely homogeneous material is received. Every sample is shredded by a 1 ∼ 2 cm 2 diameter and a representative aliquot taken for the required analysis. For verification of representative sampling, classified every group is tested for evaluation of 'selection of representative drum in a group' and 'representative sampling in a drum'

  7. Representative Sampling for reliable data analysis

    DEFF Research Database (Denmark)

    Petersen, Lars; Esbensen, Kim Harry

    2005-01-01

    regime in order to secure the necessary reliability of: samples (which must be representative, from the primary sampling onwards), analysis (which will not mean anything outside the miniscule analytical volume without representativity ruling all mass reductions involved, also in the laboratory) and data...

  8. Independent random sampling methods

    CERN Document Server

    Martino, Luca; Míguez, Joaquín

    2018-01-01

    This book systematically addresses the design and analysis of efficient techniques for independent random sampling. Both general-purpose approaches, which can be used to generate samples from arbitrary probability distributions, and tailored techniques, designed to efficiently address common real-world practical problems, are introduced and discussed in detail. In turn, the monograph presents fundamental results and methodologies in the field, elaborating and developing them into the latest techniques. The theory and methods are illustrated with a varied collection of examples, which are discussed in detail in the text and supplemented with ready-to-run computer code. The main problem addressed in the book is how to generate independent random samples from an arbitrary probability distribution with the weakest possible constraints or assumptions in a form suitable for practical implementation. The authors review the fundamental results and methods in the field, address the latest methods, and emphasize the li...

  9. 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.

  10. Sample representativeness verification of the FADN CZ farm business sample

    Directory of Open Access Journals (Sweden)

    Marie Prášilová

    2011-01-01

    Full Text Available Sample representativeness verification is one of the key stages of statistical work. After having joined the European Union the Czech Republic joined also the Farm Accountancy Data Network system of the Union. This is a sample of bodies and companies doing business in agriculture. Detailed production and economic data on the results of farming business are collected from that sample annually and results for the entire population of the country´s farms are then estimated and assessed. It is important hence, that the sample be representative. Representativeness is to be assessed as to the number of farms included in the survey and also as to the degree of accordance of the measures and indices as related to the population. The paper deals with the special statistical techniques and methods of the FADN CZ sample representativeness verification including the necessary sample size statement procedure. The Czech farm population data have been obtained from the Czech Statistical Office data bank.

  11. Towards a representative periphytic diatom sample

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The need to acquire a representative periphytic diatom sample for river water quality monitoring has been recognised in the development of existing diatom indices, important in the development and employment of diatom monitoring tools for the Water Framework Directive. In this study, a nested design with replication is employed to investigate the magnitude of variation in diatom biomass, composition and Trophic Diatom Index at varying scales within a small chalk river. The study shows that the use of artificial substrates may not result in diatom communities that are typical of the surrounding natural substrates. Periphytic diatom biomass and composition varies between artificial and natural substrates, riffles and glides and between two stretches of the river channel. The study also highlights the existence of high variation in diatom frustule frequency and biovolume at the individual replicate scale which may have implications for the use of diatoms in routine monitoring.

  12. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    International Nuclear Information System (INIS)

    Shine, E. P.; Poirier, M. R.

    2013-01-01

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  13. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    Energy Technology Data Exchange (ETDEWEB)

    Shine, E. P.; Poirier, M. R.

    2013-10-29

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  14. Testing a groundwater sampling tool: Are the samples representative?

    International Nuclear Information System (INIS)

    Kaback, D.S.; Bergren, C.L.; Carlson, C.A.; Carlson, C.L.

    1989-01-01

    A ground water sampling tool, the HydroPunch trademark, was tested at the Department of Energy's Savannah River Site in South Carolina to determine if representative ground water samples could be obtained without installing monitoring wells. Chemical analyses of ground water samples collected with the HydroPunch trademark from various depths within a borehole were compared with chemical analyses of ground water from nearby monitoring wells. The site selected for the test was in the vicinity of a large coal storage pile and a coal pile runoff basin that was constructed to collect the runoff from the coal storage pile. Existing monitoring wells in the area indicate the presence of a ground water contaminant plume that: (1) contains elevated concentrations of trace metals; (2) has an extremely low pH; and (3) contains elevated concentrations of major cations and anions. Ground water samples collected with the HydroPunch trademark provide in excellent estimate of ground water quality at discrete depths. Groundwater chemical data collected from various depths using the HydroPunch trademark can be averaged to simulate what a screen zone in a monitoring well would sample. The averaged depth-discrete data compared favorably with the data obtained from the nearby monitoring wells

  15. Representative process sampling for reliable data analysis

    DEFF Research Database (Denmark)

    Julius, Lars Petersen; Esbensen, Kim

    2005-01-01

    (sampling variances) can be reduced greatly however, and sampling biases can be eliminated completely, by respecting a simple set of rules and guidelines provided by TOS. A systematic approach for description of process heterogeneity furnishes in-depth knowledge about the specific variability of any 1-D lot...

  16. 40 CFR Appendix I to Part 261 - Representative Sampling Methods

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Representative Sampling Methods I...—Representative Sampling Methods The methods and equipment used for sampling waste materials will vary with the form and consistency of the waste materials to be sampled. Samples collected using the sampling...

  17. Risk Gambling and Personality: Results from a Representative Swedish Sample.

    Science.gov (United States)

    Sundqvist, Kristina; Wennberg, Peter

    2015-12-01

    The association between personality and gambling has been explored previously. However, few studies are based on representative populations. This study aimed at examining the association between risk gambling and personality in a representative Swedish population. A random Swedish sample (N = 19,530) was screened for risk gambling using the Lie/Bet questionnaire. The study sample (N = 257) consisted of those screening positive on Lie/Bet and completing a postal questionnaire about gambling and personality (measured with the NODS-PERC and the HP5i respectively). Risk gambling was positively correlated with Negative Affectivity (a facet of Neuroticism) and Impulsivity (an inversely related facet of Conscientiousness), but all associations were weak. When taking age and gender into account, there were no differences in personality across game preference groups, though preferred game correlated with level of risk gambling. Risk gamblers scored lower than the population norm data with respect to Negative Affectivity, but risk gambling men scored higher on Impulsivity. The association between risk gambling and personality found in previous studies was corroborated in this study using a representative sample. We conclude that risk and problem gamblers should not be treated as a homogeneous group, and prevention and treatment interventions should be adapted according to differences in personality, preferred type of game and the risk potential of the games.

  18. Sampling problems for randomly broken sticks

    Energy Technology Data Exchange (ETDEWEB)

    Huillet, Thierry [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089 et Universite de Cergy-Pontoise, 5 mail Gay-Lussac, 95031, Neuville sur Oise (France)

    2003-04-11

    Consider the random partitioning model of a population (represented by a stick of length 1) into n species (fragments) with identically distributed random weights (sizes). Upon ranking the fragments' weights according to ascending sizes, let S{sub m:n} be the size of the mth smallest fragment. Assume that some observer is sampling such populations as follows: drop at random k points (the sample size) onto this stick and record the corresponding numbers of visited fragments. We shall investigate the following sampling problems: (1) what is the sample size if the sampling is carried out until the first visit of the smallest fragment (size S{sub 1:n})? (2) For a given sample size, have all the fragments of the stick been visited at least once or not? This question is related to Feller's random coupon collector problem. (3) In what order are new fragments being discovered and what is the random number of samples separating the discovery of consecutive new fragments until exhaustion of the list? For this problem, the distribution of the size-biased permutation of the species' weights, as the sequence of their weights in their order of appearance is needed and studied.

  19. Towards Representative Metallurgical Sampling and Gold Recovery Testwork Programmes

    Directory of Open Access Journals (Sweden)

    Simon C. Dominy

    2018-05-01

    Full Text Available When developing a process flowsheet, the risks in achieving positive financial outcomes are minimised by ensuring representative metallurgical samples and high quality testwork. The quality and type of samples used are as important as the testwork itself. The key characteristic required of any set of samples is that they represent a given domain and quantify its variability. There are those who think that stating a sample(s is representative makes it representative without justification. There is a need to consider both (1 in-situ and (2 testwork sub-sample representativity. Early ore/waste characterisation and domain definition are required, so that sampling and testwork protocols can be designed to suit the style of mineralisation in question. The Theory of Sampling (TOS provides an insight into the causes and magnitude of errors that may occur during the sampling of particulate materials (e.g., broken rock and is wholly applicable to metallurgical sampling. Quality assurance/quality control (QAQC is critical throughout all programmes. Metallurgical sampling and testwork should be fully integrated into geometallurgical studies. Traditional metallurgical testwork is critical for plant design and is an inherent part of geometallurgy. In a geometallurgical study, multiple spatially distributed small-scale tests are used as proxies for process parameters. These will be validated against traditional testwork results. This paper focusses on sampling and testwork for gold recovery determination. It aims to provide the reader with the background to move towards the design, implementation and reporting of representative and fit-for-purpose sampling and testwork programmes. While the paper does not intend to provide a definitive commentary, it critically assesses the hard-rock sampling methods used and their optimal collection and preparation. The need for representative sampling and quality testwork to avoid financial and intangible losses is

  20. Systematic versus random sampling in stereological studies.

    Science.gov (United States)

    West, Mark J

    2012-12-01

    The sampling that takes place at all levels of an experimental design must be random if the estimate is to be unbiased in a statistical sense. There are two fundamental ways by which one can make a random sample of the sections and positions to be probed on the sections. Using a card-sampling analogy, one can pick any card at all out of a deck of cards. This is referred to as independent random sampling because the sampling of any one card is made without reference to the position of the other cards. The other approach to obtaining a random sample would be to pick a card within a set number of cards and others at equal intervals within the deck. Systematic sampling along one axis of many biological structures is more efficient than random sampling, because most biological structures are not randomly organized. This article discusses the merits of systematic versus random sampling in stereological studies.

  1. On the Representativeness of Norming Samples for Aptitude Test

    National Research Council Canada - National Science Library

    Sims, William

    2003-01-01

    ...). We regressed aptitude test scores on demographics and concluded that: ̂ Norming sample for aptitude tests must be representative of the target population with respect to age, race"ethnicity, gender, respondent's education, and mother's...

  2. 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.

  3. Obtaining Samples Representative of Contaminant Distribution in an Aquifer

    International Nuclear Information System (INIS)

    Schalla, Ronald; Spane, Frank A.; Narbutovskih, Susan M.; Conley, Scott F.; Webber, William D.

    2002-01-01

    Historically, groundwater samples collected from monitoring wells have been assumed to provide average indications of contaminant concentrations within the aquifer over the well-screen interval. In-well flow circulation, heterogeneity in the surrounding aquifer, and the sampling method utilized, however, can significantly impact the representativeness of samples as contaminant indicators of actual conditions within the surrounding aquifer. This paper identifies the need and approaches essential for providing cost-effective and technically meaningful groundwater-monitoring results. Proper design of the well screen interval is critical. An accurate understanding of ambient (non-pumping) flow conditions within the monitoring well is essential for determining the contaminant distribution within the aquifer. The ambient in-well flow velocity, flow direction and volumetric flux rate are key to this understanding. Not only do the ambient flow conditions need to be identified for preferential flow zones, but also the probable changes that will be imposed under dynamic conditions that occur during groundwater sampling. Once the in-well flow conditions are understood, effective sampling can be conducted to obtain representative samples for specific depth zones or zones of interest. The question of sample representativeness has become an important issue as waste minimization techniques such as low flow purging and sampling are implemented to combat the increasing cost of well purging and sampling at many hazardous waste sites. Several technical approaches (e.g., well tracer techniques and flowmeter surveys) can be used to determine in-well flow conditions, and these are discussed with respect to both their usefulness and limitations. Proper fluid extraction methods using minimal, (low) volume and no purge sampling methods that are used to obtain representative samples of aquifer conditions are presented

  4. Depression and Suicidality among Bisexual Youth: A Nationally Representative Sample

    Science.gov (United States)

    Taliaferro, Lindsay A.; Gloppen, Kari M.; Muehlenkamp, Jennifer J.; Eisenberg, Marla E.

    2018-01-01

    To address gaps in the literature on bisexual youth, we used the first nationally representative sample of high school students from the United States to determine profiles of behaviors related to depressive symptoms, a suicide attempt, and a medically-serious attempt. We examined the data from 922 bisexual students in grades 9-12 who completed…

  5. k-Means: Random Sampling Procedure

    Indian Academy of Sciences (India)

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

  6. On the representativeness of behavior observation samples in classrooms.

    Science.gov (United States)

    Tiger, Jeffrey H; Miller, Sarah J; Mevers, Joanna Lomas; Mintz, Joslyn Cynkus; Scheithauer, Mindy C; Alvarez, Jessica

    2013-01-01

    School consultants who rely on direct observation typically conduct observational samples (e.g., 1 30-min observation per day) with the hopes that the sample is representative of performance during the remainder of the day, but the representativeness of these samples is unclear. In the current study, we recorded the problem behavior of 3 referred students for 4 consecutive school days between 9:30 a.m. and 2:30 p.m. using duration recording in consecutive 10-min sessions. We then culled 10-min, 20-min, 30-min, and 60-min observations from the complete record and compared these observations to the true daily mean to assess their accuracy (i.e., how well individual observations represented the daily occurrence of target behaviors). The results indicated that when behavior occurred with low variability, the majority of brief observations were representative of the overall levels; however, when behavior occurred with greater variability, even 60-min observations did not accurately capture the true levels of behavior. © Society for the Experimental Analysis of Behavior.

  7. 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.

  8. Early menarche and childhood adversities in a nationally representative sample

    OpenAIRE

    Henrichs, Kimberly L; McCauley, Heather L; Miller, Elizabeth; Styne, Dennis M; Saito, Naomi; Breslau, Joshua

    2014-01-01

    Background Epidemiological evidence suggests that early menarche, defined as onset of menses at age 11 or earlier, has increased in prevalence in recent birth cohorts and is associated with multiple poor medical and mental health outcomes in adulthood. There is evidence that childhood adversities occurring prior to menarche contribute to early menarche. Methods Data collected in face-to-face interviews with a nationally representative sample of women age 18 and over (N = 3288), as part of the...

  9. In search of a representative sample of residential building work.

    Science.gov (United States)

    Lobb, Brenda; Woods, Gregory R

    2012-09-01

    Most research investigating injuries in construction work is limited by reliance on work samples unrepresentative of the multiple, variable-cycle tasks involved, resulting in incomplete characterisation of ergonomic exposures. In this case study, a participatory approach was used including hierarchical task analysis and site observations of a typical team of house builders in New Zealand, over several working days, to obtain a representative work sample. The builders' work consisted of 14 goal-defined jobs using varying subsets of 15 task types, each taking from less than 1 s to more than 1 h and performed in a variety of postures. Task type and duration varied within and between participants and days, although all participants spent at least 25% of the time moving from place to place, mostly carrying materials, and more than half the time either reaching up or bending down to work. This research has provided a description of residential building work based on a work sample more nearly representative than those previously published and has demonstrated a simple, low-cost but robust field observation method that can provide a valid basis for further study of hazard exposures. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. An unbiased estimator of the variance of simple random sampling using mixed random-systematic sampling

    OpenAIRE

    Padilla, Alberto

    2009-01-01

    Systematic sampling is a commonly used technique due to its simplicity and ease of implementation. The drawback of this simplicity is that it is not possible to estimate the design variance without bias. There are several ways to circumvent this problem. One method is to suppose that the variable of interest has a random order in the population, so the sample variance of simple random sampling without replacement is used. By means of a mixed random - systematic sample, an unbiased estimator o...

  11. Spatiotemporally Representative and Cost-Efficient Sampling Design for Validation Activities in Wanglang Experimental Site

    Directory of Open Access Journals (Sweden)

    Gaofei Yin

    2017-11-01

    Full Text Available Spatiotemporally representative Elementary Sampling Units (ESUs are required for capturing the temporal variations in surface spatial heterogeneity through field measurements. Since inaccessibility often coexists with heterogeneity, a cost-efficient sampling design is mandatory. We proposed a sampling strategy to generate spatiotemporally representative and cost-efficient ESUs based on the conditioned Latin hypercube sampling scheme. The proposed strategy was constrained by multi-temporal Normalized Difference Vegetation Index (NDVI imagery, and the ESUs were limited within a sampling feasible region established based on accessibility criteria. A novel criterion based on the Overlapping Area (OA between the NDVI frequency distribution histogram from the sampled ESUs and that from the entire study area was used to assess the sampling efficiency. A case study in Wanglang National Nature Reserve in China showed that the proposed strategy improves the spatiotemporally representativeness of sampling (mean annual OA = 74.7% compared to the single-temporally constrained (OA = 68.7% and the random sampling (OA = 63.1% strategies. The introduction of the feasible region constraint significantly reduces in-situ labour-intensive characterization necessities at expenses of about 9% loss in the spatiotemporal representativeness of the sampling. Our study will support the validation activities in Wanglang experimental site providing a benchmark for locating the nodes of automatic observation systems (e.g., LAINet which need a spatially distributed and temporally fixed sampling design.

  12. Examination of Hydrate Formation Methods: Trying to Create Representative Samples

    Energy Technology Data Exchange (ETDEWEB)

    Kneafsey, T.J.; Rees, E.V.L.; Nakagawa, S.; Kwon, T.-H.

    2011-04-01

    Forming representative gas hydrate-bearing laboratory samples is important so that the properties of these materials may be measured, while controlling the composition and other variables. Natural samples are rare, and have often experienced pressure and temperature changes that may affect the property to be measured [Waite et al., 2008]. Forming methane hydrate samples in the laboratory has been done a number of ways, each having advantages and disadvantages. The ice-to-hydrate method [Stern et al., 1996], contacts melting ice with methane at the appropriate pressure to form hydrate. The hydrate can then be crushed and mixed with mineral grains under controlled conditions, and then compacted to create laboratory samples of methane hydrate in a mineral medium. The hydrate in these samples will be part of the load-bearing frame of the medium. In the excess gas method [Handa and Stupin, 1992], water is distributed throughout a mineral medium (e.g. packed moist sand, drained sand, moistened silica gel, other porous media) and the mixture is brought to hydrate-stable conditions (chilled and pressurized with gas), allowing hydrate to form. This method typically produces grain-cementing hydrate from pendular water in sand [Waite et al., 2004]. In the dissolved gas method [Tohidi et al., 2002], water with sufficient dissolved guest molecules is brought to hydrate-stable conditions where hydrate forms. In the laboratory, this is can be done by pre-dissolving the gas of interest in water and then introducing it to the sample under the appropriate conditions. With this method, it is easier to form hydrate from more soluble gases such as carbon dioxide. It is thought that this method more closely simulates the way most natural gas hydrate has formed. Laboratory implementation, however, is difficult, and sample formation is prohibitively time consuming [Minagawa et al., 2005; Spangenberg and Kulenkampff, 2005]. In another version of this technique, a specified quantity of gas

  13. Sampling device for withdrawing a representative sample from single and multi-phase flows

    Science.gov (United States)

    Apley, Walter J.; Cliff, William C.; Creer, James M.

    1984-01-01

    A fluid stream sampling device has been developed for the purpose of obtaining a representative sample from a single or multi-phase fluid flow. This objective is carried out by means of a probe which may be inserted into the fluid stream. Individual samples are withdrawn from the fluid flow by sampling ports with particular spacings, and the sampling parts are coupled to various analytical systems for characterization of the physical, thermal, and chemical properties of the fluid flow as a whole and also individually.

  14. Examining the "Veggie" personality: Results from a representative German sample.

    Science.gov (United States)

    Pfeiler, Tamara M; Egloff, Boris

    2018-01-01

    An increasing proportion of people choose to follow a vegetarian diet. To date, however, little is known about if and how individual differences in personality relate to following a vegetarian diet. In the two studies presented here, we aimed to (1) estimate the prevalence of self-defined vegetarians in two waves of a German representative sample (N = 4496 and 5125, respectively), (2) analyze the effect of socio-demographic variables on dietary behavior, and (3) examine individual differences between vegetarians and meat eaters in personality traits, political attitudes, and health-related variables. In Study 1, a strict definition of vegetarians was used, while in Study 2 the definition was laxer, to include also individuals who only predominantly followed a vegetarian diet. The prevalence of self-defined vegetarians was 2.74% in Study 1, and 5.97% in Study 2. Participants who were female, younger, and more educated were more likely to report following a vegetarian diet in both studies, and vegetarians had higher income as compared to meat eaters in Study 2. We also found differences between vegetarians and meat eaters with regard to personality traits, political attitudes, and health-related variables. Stepwise logistic regression analyses showed a unique effect beyond socio-demographic variables for openness (Studies 1 and 2), conscientiousness (Study 1), trust (Study 2), conservatism (Studies 1 and 2), and level of interest in politics (Study 1) on diet: Individuals with higher scores in openness and political interest had a higher probability of being vegetarian, whereas people with higher scores in conscientiousness and conservatism had a smaller likelihood of being vegetarian. We conclude that there are individual differences between vegetarians and meat eaters in socio-demographics, personality traits, and political attitudes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Early menarche and childhood adversities in a nationally representative sample.

    Science.gov (United States)

    Henrichs, Kimberly L; McCauley, Heather L; Miller, Elizabeth; Styne, Dennis M; Saito, Naomi; Breslau, Joshua

    2014-01-01

    Epidemiological evidence suggests that early menarche, defined as onset of menses at age 11 or earlier, has increased in prevalence in recent birth cohorts and is associated with multiple poor medical and mental health outcomes in adulthood. There is evidence that childhood adversities occurring prior to menarche contribute to early menarche. Data collected in face-to-face interviews with a nationally representative sample of women age 18 and over (N = 3288), as part of the National Comorbidity Survey-Replication, were analyzed. Associations between pre-menarchal childhood adversities and menarche at age 11 or earlier were estimated in discrete time survival models with statistical adjustment for age at interview, ethnicity, and body mass index. Adversities investigated included physical abuse, sexual abuse, neglect, biological father absence from the home, other parent loss, parent mental illness, parent substance abuse, parent criminality, inter-parental violence, serious physical illness in childhood, and family economic adversity. Mean age at menarche varied across decadal birth cohorts (χ(2)₍₄₎ = 21.41, p Childhood adversities were also more common in younger than older cohorts. Of the 11 childhood adversities, 5 were associated with menarche at age 11 or earlier, with OR of 1.3 or greater. Each of these five adversities is associated with a 26% increase in the odds of early menarche (OR = 1.26, 95% CI 1.14-1.39). The relationship between childhood sexual abuse and early menarche was sustained after adjustment for co-occurring adversities. (OR = 1.77, 95% CI 1.21-2.6). Evidence from this study is consistent with hypothesized physiological effects of early childhood family environment on endocrine development. Childhood sexual abuse is the adversity most strongly associated with early menarche. However, because of the complex way that childhood adversities cluster within families, the more generalized influence of highly dysfunctional

  16. Generation and Analysis of Constrained Random Sampling Patterns

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas

    2016-01-01

    Random sampling is a technique for signal acquisition which is gaining popularity in practical signal processing systems. Nowadays, event-driven analog-to-digital converters make random sampling feasible in practical applications. A process of random sampling is defined by a sampling pattern, which...... indicates signal sampling points in time. Practical random sampling patterns are constrained by ADC characteristics and application requirements. In this paper, we introduce statistical methods which evaluate random sampling pattern generators with emphasis on practical applications. Furthermore, we propose...... algorithm generates random sampling patterns dedicated for event-driven-ADCs better than existed sampling pattern generators. Finally, implementation issues of random sampling patterns are discussed....

  17. Associated factors of obesity in Spanish representative samples.

    Science.gov (United States)

    Ortega Anta, Rosa M; López-Solaber, Ana M; Pérez-Farinós, Napoleón

    2013-09-01

    Given the dramatic increase in the prevalence of obesity and the serious health and economic consequences, the scientific community, health professionals and health agencies are looking for the best strategies to prevent/ fight this trend. In order to plan the most appropriate intervention measures the first step is to identify the associated factors of obesity. This paper presents the results of research conducted/coordinated by our research team and promoted by the Spanish Food Safety Agency (AESAN), in the last five years. These studies were focussed on representative samples of the Spanish population, paying attention to the condition of overweight/obesity and their associated factors. The first study, FANPE ("Fuentes alimentarias de nutrientes de la población española") (2009), was centered in 418 adults (18-60 years) from 15 provinces (30 sampling points). Its aim was to analyze the dietary sources of nutrients, paying particular attention to sodium. This research showed that the risk of overweight/obesity increa ses with age, in people who have follow weight control diets, in ex-smokers, married people and those who slept less than 8.5 hours per day, while the risk is lower in women, people who make sport and those with a University degree. It was also found that overweight people had higher sodium intake and urine excretion. Therefore, and having in mind that 88.2% of the subjects took more than 2 g/day of sodium (the maximum recommended), it is advised to lower the sodium intake not only from the health point of view but also as a probably strategy against obesity. The study ALADINO (Estudio de Alimentación, Actividad física, Desarrollo Infantil y Obesidad--Study of the Diet, Physical Activity, Child Development and Obesity) (2010-2011) was focused on 7659 children (6-9 years) from 19 autonomous communities. We founded a higher percentage of overweight/obesity in boys than in girls, and a significant increase in the figures from the age of 7. Being

  18. 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.

  19. A random sampling procedure for anisotropic distributions

    International Nuclear Information System (INIS)

    Nagrajan, P.S.; Sethulakshmi, P.; Raghavendran, C.P.; Bhatia, D.P.

    1975-01-01

    A procedure is described for sampling the scattering angle of neutrons as per specified angular distribution data. The cosine of the scattering angle is written as a double Legendre expansion in the incident neutron energy and a random number. The coefficients of the expansion are given for C, N, O, Si, Ca, Fe and Pb and these elements are of interest in dosimetry and shielding. (author)

  20. Studying the sampling representativeness in the NPP ventilation ducts

    International Nuclear Information System (INIS)

    Sosnovskij, R.I.; Fedchenko, T.K.; Minin, S.A.

    2000-01-01

    Measurements of the gas and aerosol voluminous activity in the NPP ventilation ducts are an important source of information on the radiation contaminants ingress into the environmental medium. These measurements include sampling, samples transport and proper measurements. The work is devoted to calculation of metrological characteristics of the sampling systems for the NPP gas-aerosol releases by different parameters of these systems and ventilation ducts. The results obtained are intended for application by designing such systems and their metrological certification [ru

  1. Systematic random sampling of the comet assay.

    Science.gov (United States)

    McArt, Darragh G; Wasson, Gillian R; McKerr, George; Saetzler, Kurt; Reed, Matt; Howard, C Vyvyan

    2009-07-01

    The comet assay is a technique used to quantify DNA damage and repair at a cellular level. In the assay, cells are embedded in agarose and the cellular content is stripped away leaving only the DNA trapped in an agarose cavity which can then be electrophoresed. The damaged DNA can enter the agarose and migrate while the undamaged DNA cannot and is retained. DNA damage is measured as the proportion of the migratory 'tail' DNA compared to the total DNA in the cell. The fundamental basis of these arbitrary values is obtained in the comet acquisition phase using fluorescence microscopy with a stoichiometric stain in tandem with image analysis software. Current methods deployed in such an acquisition are expected to be both objectively and randomly obtained. In this paper we examine the 'randomness' of the acquisition phase and suggest an alternative method that offers both objective and unbiased comet selection. In order to achieve this, we have adopted a survey sampling approach widely used in stereology, which offers a method of systematic random sampling (SRS). This is desirable as it offers an impartial and reproducible method of comet analysis that can be used both manually or automated. By making use of an unbiased sampling frame and using microscope verniers, we are able to increase the precision of estimates of DNA damage. Results obtained from a multiple-user pooled variation experiment showed that the SRS technique attained a lower variability than that of the traditional approach. The analysis of a single user with repetition experiment showed greater individual variances while not being detrimental to overall averages. This would suggest that the SRS method offers a better reflection of DNA damage for a given slide and also offers better user reproducibility.

  2. BWIP-RANDOM-SAMPLING, Random Sample Generation for Nuclear Waste Disposal

    International Nuclear Information System (INIS)

    Sagar, B.

    1989-01-01

    1 - Description of program or function: Random samples for different distribution types are generated. Distribution types as required for performance assessment modeling of geologic nuclear waste disposal are provided. These are: - Uniform, - Log-uniform (base 10 or natural), - Normal, - Lognormal (base 10 or natural), - Exponential, - Bernoulli, - User defined continuous distribution. 2 - Method of solution: A linear congruential generator is used for uniform random numbers. A set of functions is used to transform the uniform distribution to the other distributions. Stratified, rather than random, sampling can be chosen. Truncated limits can be specified on many distributions, whose usual definition has an infinite support. 3 - Restrictions on the complexity of the problem: Generation of correlated random variables is not included

  3. STATISTICAL LANDMARKS AND PRACTICAL ISSUES REGARDING THE USE OF SIMPLE RANDOM SAMPLING IN MARKET RESEARCHES

    Directory of Open Access Journals (Sweden)

    CODRUŢA DURA

    2010-01-01

    Full Text Available The sample represents a particular segment of the statistical populationchosen to represent it as a whole. The representativeness of the sample determines the accuracyfor estimations made on the basis of calculating the research indicators and the inferentialstatistics. The method of random sampling is part of probabilistic methods which can be usedwithin marketing research and it is characterized by the fact that it imposes the requirementthat each unit belonging to the statistical population should have an equal chance of beingselected for the sampling process. When the simple random sampling is meant to be rigorouslyput into practice, it is recommended to use the technique of random number tables in order toconfigure the sample which will provide information that the marketer needs. The paper alsodetails the practical procedure implemented in order to create a sample for a marketingresearch by generating random numbers using the facilities offered by Microsoft Excel.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  5. 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.

  6. Correlated random sampling for multivariate normal and log-normal distributions

    International Nuclear Information System (INIS)

    Žerovnik, Gašper; Trkov, Andrej; Kodeli, Ivan A.

    2012-01-01

    A method for correlated random sampling is presented. Representative samples for multivariate normal or log-normal distribution can be produced. Furthermore, any combination of normally and log-normally distributed correlated variables may be sampled to any requested accuracy. Possible applications of the method include sampling of resonance parameters which are used for reactor calculations.

  7. Prevalence and correlates of bullying victimisation and perpetration in a nationally representative sample of Australian youth.

    Science.gov (United States)

    Thomas, Hannah J; Connor, Jason P; Lawrence, David M; Hafekost, Jennifer M; Zubrick, Stephen R; Scott, James G

    2017-09-01

    Bullying prevalence studies are limited by varied measurement methods and a lack of representative samples. This study estimated the national prevalence of bullying victimisation, perpetration and combined victim-perpetration experiences in a representative population-based sample of Australian youth. The relationships between the three types of bullying involvement with a range of mental health symptoms and diagnoses were also examined. A randomly selected nationally representative sample aged 11-17 years ( N = 2967, M age = 14.6 years; 51.6% male) completed the youth component of the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing (Young Minds Matter). Parents or carers also completed a structured face-to-face interview that asked questions about a single randomly selected child in the household. The youth survey comprised self-reported bullying victimisation and perpetration (Olweus Bully-Victim Questionnaire-adapted), psychological distress (K10), emotional and behavioural problems (Strengths and Difficulties Questionnaire), as well as self-harm, suicide attempts and substance use. Modules from the Diagnostic Interview Schedule for Children Version IV were administered to all youth and parents to assess for mental disorder diagnoses (major depressive disorder, any anxiety disorder and any externalising disorder [attention-deficit hyperactivity disorder, oppositional defiant disorder and conduct disorder]). The 12-month prevalence of bullying victimisation was 13.3%, perpetration 1.6% and victim-perpetration 1.9%. Logistic regression models showed all forms of involvement in bullying were associated with increased risk of psychological distress, emotional and behavioural problems, substance use, self-harm and attempted suicide. Victimisation and victim-perpetration were associated with youth-reported major depressive disorder. There were also significant associations between bullying involvement and parent-reported diagnoses of major

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

    Science.gov (United States)

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

    2014-01-01

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

  9. Power Spectrum Estimation of Randomly Sampled Signals

    DEFF Research Database (Denmark)

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

    algorithms; sample and-hold and the direct spectral estimator without residence time weighting. The computer generated signal is a Poisson process with a sample rate proportional to velocity magnitude that consist of well-defined frequency content, which makes bias easy to spot. The idea...

  10. Are Video Games a Gateway to Gambling? A Longitudinal Study Based on a Representative Norwegian Sample.

    Science.gov (United States)

    Molde, Helge; Holmøy, Bjørn; Merkesdal, Aleksander Garvik; Torsheim, Torbjørn; Mentzoni, Rune Aune; Hanns, Daniel; Sagoe, Dominic; Pallesen, Ståle

    2018-06-05

    The scope and variety of video games and monetary gambling opportunities are expanding rapidly. In many ways, these forms of entertainment are converging on digital and online video games and gambling sites. However, little is known about the relationship between video gaming and gambling. The present study explored the possibility of a directional relationship between measures of problem gaming and problem gambling, while also controlling for the influence of sex and age. In contrast to most previous investigations which are based on cross-sectional designs and non-representative samples, the present study utilized a longitudinal design conducted over 2 years (2013, 2015) and comprising 4601 participants (males 47.2%, age range 16-74) drawn from a random sample from the general population. Video gaming and gambling were assessed using the Gaming Addiction Scale for Adolescents and the Canadian Problem Gambling Index, respectively. Using an autoregressive cross-lagged structural equation model, we found a positive relationship between scores on problematic gaming and later scores on problematic gambling, whereas we found no evidence of the reverse relationship. Hence, video gaming problems appear to be a gateway behavior to problematic gambling behavior. In future research, one should continue to monitor the possible reciprocal behavioral influences between gambling and video gaming.

  11. Assessing terpene content variability of whitebark pine in order to estimate representative sample size

    Directory of Open Access Journals (Sweden)

    Stefanović Milena

    2013-01-01

    Full Text Available In studies of population variability, particular attention has to be paid to the selection of a representative sample. The aim of this study was to assess the size of the new representative sample on the basis of the variability of chemical content of the initial sample on the example of a whitebark pine population. Statistical analysis included the content of 19 characteristics (terpene hydrocarbons and their derivates of the initial sample of 10 elements (trees. It was determined that the new sample should contain 20 trees so that the mean value calculated from it represents a basic set with a probability higher than 95 %. Determination of the lower limit of the representative sample size that guarantees a satisfactory reliability of generalization proved to be very important in order to achieve cost efficiency of the research. [Projekat Ministarstva nauke Republike Srbije, br. OI-173011, br. TR-37002 i br. III-43007

  12. Assessing representativeness of sampling methods for reaching men who have sex with men: a direct comparison of results obtained from convenience and probability samples.

    Science.gov (United States)

    Schwarcz, Sandra; Spindler, Hilary; Scheer, Susan; Valleroy, Linda; Lansky, Amy

    2007-07-01

    Convenience samples are used to determine HIV-related behaviors among men who have sex with men (MSM) without measuring the extent to which the results are representative of the broader MSM population. We compared results from a cross-sectional survey of MSM recruited from gay bars between June and October 2001 to a random digit dial telephone survey conducted between June 2002 and January 2003. The men in the probability sample were older, better educated, and had higher incomes than men in the convenience sample, the convenience sample enrolled more employed men and men of color. Substance use around the time of sex was higher in the convenience sample but other sexual behaviors were similar. HIV testing was common among men in both samples. Periodic validation, through comparison of data collected by different sampling methods, may be useful when relying on survey data for program and policy development.

  13. 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.

  14. Patterns of Childhood Abuse and Neglect in a Representative German Population Sample.

    Directory of Open Access Journals (Sweden)

    Christoph Schilling

    Full Text Available Different types of childhood maltreatment, like emotional abuse, emotional neglect, physical abuse, physical neglect and sexual abuse are interrelated because of their co-occurrence. Different patterns of childhood abuse and neglect are associated with the degree of severity of mental disorders in adulthood. The purpose of this study was (a to identify different patterns of childhood maltreatment in a representative German community sample, (b to replicate the patterns of childhood neglect and abuse recently found in a clinical German sample, (c to examine whether participants reporting exposure to specific patterns of child maltreatment would report different levels of psychological distress, and (d to compare the results of the typological approach and the results of a cumulative risk model based on our data set.In a cross-sectional survey conducted in 2010, a representative random sample of 2504 German participants aged between 14 and 92 years completed the Childhood Trauma Questionnaire (CTQ. General anxiety and depression were assessed by standardized questionnaires (GAD-2, PHQ-2. Cluster analysis was conducted with the CTQ-subscales to identify different patterns of childhood maltreatment.Three different patterns of childhood abuse and neglect could be identified by cluster analysis. Cluster one showed low values on all CTQ-scales. Cluster two showed high values in emotional and physical neglect. Only cluster three showed high values in physical and sexual abuse. The three patterns of childhood maltreatment showed different degrees of depression (PHQ-2 and anxiety (GAD-2. Cluster one showed lowest levels of psychological distress, cluster three showed highest levels of mental distress.The results show that different types of childhood maltreatment are interrelated and can be grouped into specific patterns of childhood abuse and neglect, which are associated with differing severity of psychological distress in adulthood. The results

  15. Patterns of Childhood Abuse and Neglect in a Representative German Population Sample

    Science.gov (United States)

    Schilling, Christoph; Weidner, Kerstin; Brähler, Elmar; Glaesmer, Heide; Häuser, Winfried; Pöhlmann, Karin

    2016-01-01

    Background Different types of childhood maltreatment, like emotional abuse, emotional neglect, physical abuse, physical neglect and sexual abuse are interrelated because of their co-occurrence. Different patterns of childhood abuse and neglect are associated with the degree of severity of mental disorders in adulthood. The purpose of this study was (a) to identify different patterns of childhood maltreatment in a representative German community sample, (b) to replicate the patterns of childhood neglect and abuse recently found in a clinical German sample, (c) to examine whether participants reporting exposure to specific patterns of child maltreatment would report different levels of psychological distress, and (d) to compare the results of the typological approach and the results of a cumulative risk model based on our data set. Methods In a cross-sectional survey conducted in 2010, a representative random sample of 2504 German participants aged between 14 and 92 years completed the Childhood Trauma Questionnaire (CTQ). General anxiety and depression were assessed by standardized questionnaires (GAD-2, PHQ-2). Cluster analysis was conducted with the CTQ-subscales to identify different patterns of childhood maltreatment. Results Three different patterns of childhood abuse and neglect could be identified by cluster analysis. Cluster one showed low values on all CTQ-scales. Cluster two showed high values in emotional and physical neglect. Only cluster three showed high values in physical and sexual abuse. The three patterns of childhood maltreatment showed different degrees of depression (PHQ-2) and anxiety (GAD-2). Cluster one showed lowest levels of psychological distress, cluster three showed highest levels of mental distress. Conclusion The results show that different types of childhood maltreatment are interrelated and can be grouped into specific patterns of childhood abuse and neglect, which are associated with differing severity of psychological distress in

  16. Sleepiness and Motor Vehicle Crashes in a Representative Sample of Portuguese Drivers: The Importance of Epidemiological Representative Surveys.

    Science.gov (United States)

    Gonçalves, M; Peralta, A R; Monteiro Ferreira, J; Guilleminault, Christian

    2015-01-01

    Sleepiness is considered to be a leading cause of crashes. Despite the huge amount of information collected in questionnaire studies, only some are based on representative samples of the population. Specifics of the populations studied hinder the generalization of these previous findings. For the Portuguese population, data from sleep-related car crashes/near misses and sleepiness while driving are missing. The objective of this study is to determine the prevalence of near-miss and nonfatal motor vehicle crashes related to sleepiness in a representative sample of Portuguese drivers. Structured phone interviews regarding sleepiness and sleep-related crashes and near misses, driving habits, demographic data, and sleep quality were conducted using the Pittsburgh Sleep Quality Index and sleep apnea risk using the Berlin questionnaire. A multivariate regression analysis was used to determine the associations with sleepy driving (feeling sleepy or falling asleep while driving) and sleep-related near misses and crashes. Nine hundred subjects, representing the Portuguese population of drivers, were included; 3.1% acknowledged falling asleep while driving during the previous year and 0.67% recalled sleepiness-related crashes. Higher education, driving more than 15,000 km/year, driving more frequently between 12:00 a.m. and 6 a.m., fewer years of having a driver's license, less total sleep time per night, and higher scores on the Epworth Sleepiness Scale (ESS) were all independently associated with sleepy driving. Sleepiness-related crashes and near misses were associated only with falling asleep at the wheel in the previous year. Sleep-related crashes occurred more frequently in drivers who had also had sleep-related near misses. Portugal has lower self-reported sleepiness at the wheel and sleep-related near misses than most other countries where epidemiological data are available. Different population characteristics and cultural, social, and road safety specificities may

  17. Determinants of Childhood Obesity in Representative Sample of Children in North East of Iran

    Directory of Open Access Journals (Sweden)

    Fereshteh Baygi

    2012-01-01

    Full Text Available Childhood obesity has become, a global public health problem, and epidemiological studies are important to identify its determinants in different populations. This study aimed to investigate factors associated with obesity in a representative sample of children in Neishabour, Iran. This study was conducted among 1500 randomly selected 6–12-year-old students from urban areas of Neishabour, northeast of Iran. Then, through a case-control study, 114 obese (BMI≥95th percentile of Iranian reference children were selected as the case group and were compared with 102 controls (15th≤BMI<85th percentile. Factors suggested to be associated with weight status were investigated, for example, parental obesity, child physical activity levels, socio-economic status (SES, and so forth. The analysis was conducted using univariate and multivariate logistic regression (MLR in SPSS version 16. In univariate logistic regression model, birth weight, birth order, family extension, TV watching, sleep duration, physical activity, parents’ job, parents’ education, parental obesity history, and SES were significantly associated with children’s obesity. After MLR analysis, physical activity and parental obesity history remained statistically significant in the model. Our findings showed that physical activity and parental obesity history are the most important determinants for childhood obesity in our population. This finding should be considered in implementation of preventive interventions.

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

    Science.gov (United States)

    Biro, Peter A

    2013-02-01

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

  19. Difficulties in obtaining representative samples for compliance with the Ballast Water Management Convention

    Digital Repository Service at National Institute of Oceanography (India)

    Carney, K.J; Basurko, O.C; Pazouki, K.; Marsham, S.; Delany, J; Desai, D.V.; Anil, A.C; Mesbahi, E.

    water, the shape, size and number of ballast tanks and the heterogeneous distribution of organisms within tanks. These factors hinder efforts to obtain samples that truly represent the total ballast water onboard a vessel. A known cell density...

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

    DEFF Research Database (Denmark)

    Schou, Mads Fristrup

    2013-01-01

    When obtaining samples for population genetic studies, it is essential that the sampling is random. For Drosophila, one of the crucial steps in sampling experimental flies is the collection of eggs. Here an egg collection method is presented, which randomizes the eggs in a water column...... and diminishes environmental variance. This method was compared with a traditional egg collection method where eggs are collected directly from the medium. Within each method the observed and expected standard deviations of egg-to-adult viability were compared, whereby the difference in the randomness...... and to obtain a representative collection of genotypes, the method presented here is strongly recommended when collecting eggs from Drosophila....

  1. 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...

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

    Science.gov (United States)

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

    2018-02-01

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

  3. Representativeness-based sampling network design for the State of Alaska

    Science.gov (United States)

    Forrest M. Hoffman; Jitendra Kumar; Richard T. Mills; William W. Hargrove

    2013-01-01

    Resource and logistical constraints limit the frequency and extent of environmental observations, particularly in the Arctic, necessitating the development of a systematic sampling strategy to maximize coverage and objectively represent environmental variability at desired scales. A quantitative methodology for stratifying sampling domains, informing site selection,...

  4. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2009-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6 - 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  5. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2008-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6- 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  6. Recruiting a representative sample in adherence research-The MALT multisite prospective cohort study experience.

    Science.gov (United States)

    Shemesh, Eyal; Mitchell, Jeffrey; Neighbors, Katie; Feist, Susan; Hawkins, Andre; Brown, Amanda; Wanrong, Yin; Anand, Ravinder; Stuber, Margaret L; Annunziato, Rachel A

    2017-12-01

    Medication adherence is an important determinant of transplant outcomes. Attempts to investigate adherence are frequently undermined by selection bias: It is very hard to recruit and retain non-adherent patients in research efforts. This manuscript presents recruitment strategies and results from the MALT (Medication Adherence in children who had a Liver Transplant) multisite prospective cohort study. MALT sites recruited 400 pediatric liver transplant patients who agreed to be followed for 2 years. The primary purpose was to determine whether a marker of adherence, the Medication Level Variability Index (MLVI), predicts rejection outcomes. The present manuscript describes methods used in MALT to ensure that a representative sample was recruited, and presents detailed recruitment results. MALT sites were able to recruit a nationally representative sample, as determined by a comparison between the MALT cohort and a national sample of transplant recipients. Strategies that helped ensure that the sample was representative included monitoring of the outcome measure in comparison with a national sample, drastically limiting patient burden, and specific recruitment methods. We discuss the importance of a representative sample in adherence research and recommend that future efforts to study adherence pay special attention to sample characteristics. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Sampling large random knots in a confined space

    International Nuclear Information System (INIS)

    Arsuaga, J; Blackstone, T; Diao, Y; Hinson, K; Karadayi, E; Saito, M

    2007-01-01

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

  8. Sampling large random knots in a confined space

    Science.gov (United States)

    Arsuaga, J.; Blackstone, T.; Diao, Y.; Hinson, K.; Karadayi, E.; Saito, M.

    2007-09-01

    DNA knots formed under extreme conditions of condensation, as in bacteriophage P4, are difficult to analyze experimentally and theoretically. In this paper, we propose to use the uniform random polygon model as a supplementary method to the existing methods for generating random knots in confinement. The uniform random polygon model allows us to sample knots with large crossing numbers and also to generate large diagrammatically prime knot diagrams. We show numerically that uniform random polygons sample knots with large minimum crossing numbers and certain complicated knot invariants (as those observed experimentally). We do this in terms of the knot determinants or colorings. Our numerical results suggest that the average determinant of a uniform random polygon of n vertices grows faster than O(e^{n^2}) . We also investigate the complexity of prime knot diagrams. We show rigorously that the probability that a randomly selected 2D uniform random polygon of n vertices is almost diagrammatically prime goes to 1 as n goes to infinity. Furthermore, the average number of crossings in such a diagram is at the order of O(n2). Therefore, the two-dimensional uniform random polygons offer an effective way in sampling large (prime) knots, which can be useful in various applications.

  9. Sampling large random knots in a confined space

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-28

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

  10. Prevalence of Childhood Physical Abuse in a Representative Sample of College Students in Samsun, Turkey

    Science.gov (United States)

    Turla, Ahmet; Dundar, Cihad; Ozkanli, Caglar

    2010-01-01

    The main objective of this article is to obtain the prevalence of childhood physical abuse experiences in college students. This cross-sectional study was performed on a gender-stratified random sample of 988 participants studying at Ondokuz Mayis University, with self-reported anonymous questionnaires. It included questions on physical abuse in…

  11. SOME SYSTEMATIC SAMPLING STRATEGIES USING MULTIPLE RANDOM STARTS

    OpenAIRE

    Sampath Sundaram; Ammani Sivaraman

    2010-01-01

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

  12. Phylogenetic representativeness: a new method for evaluating taxon sampling in evolutionary studies

    Directory of Open Access Journals (Sweden)

    Passamonti Marco

    2010-04-01

    Full Text Available Abstract Background Taxon sampling is a major concern in phylogenetic studies. Incomplete, biased, or improper taxon sampling can lead to misleading results in reconstructing evolutionary relationships. Several theoretical methods are available to optimize taxon choice in phylogenetic analyses. However, most involve some knowledge about the genetic relationships of the group of interest (i.e., the ingroup, or even a well-established phylogeny itself; these data are not always available in general phylogenetic applications. Results We propose a new method to assess taxon sampling developing Clarke and Warwick statistics. This method aims to measure the "phylogenetic representativeness" of a given sample or set of samples and it is based entirely on the pre-existing available taxonomy of the ingroup, which is commonly known to investigators. Moreover, our method also accounts for instability and discordance in taxonomies. A Python-based script suite, called PhyRe, has been developed to implement all analyses we describe in this paper. Conclusions We show that this method is sensitive and allows direct discrimination between representative and unrepresentative samples. It is also informative about the addition of taxa to improve taxonomic coverage of the ingroup. Provided that the investigators' expertise is mandatory in this field, phylogenetic representativeness makes up an objective touchstone in planning phylogenetic studies.

  13. Associations among School Characteristics and Foodservice Practices in a Nationally Representative Sample of United States Schools

    Science.gov (United States)

    Thomson, Jessica L.; Tussing-Humphreys, Lisa M.; Martin, Corby K.; LeBlanc, Monique M.; Onufrak, Stephen J.

    2012-01-01

    Objective: Determine school characteristics associated with healthy/unhealthy food service offerings or healthy food preparation practices. Design: Secondary analysis of cross-sectional data. Setting: Nationally representative sample of public and private elementary, middle, and high schools. Participants: Data from the 2006 School Health Policies…

  14. 76 FR 69585 - Testing and Labeling Pertaining to Product Certification Regarding Representative Samples for...

    Science.gov (United States)

    2011-11-08

    ... 1107 Testing and Labeling Pertaining to Product Certification Regarding Representative Samples for... [CPSC Docket No. CPSC-2011-0082] Testing and Labeling Pertaining to Product Certification Regarding... to Product Certification.'' The proposed rule was intended to implement what was then known as...

  15. Age Differences in Personality: Evidence from a Nationally Representative Australian Sample

    Science.gov (United States)

    Lucas, Richard E.; Donnellan, M. Brent

    2009-01-01

    Cross-sectional age differences in the Big Five personality traits were examined in a nationally representative sample of Australians (N = 12,618; age range = 15-84). Extraversion, Neuroticism, and Openness were negatively associated with age, whereas Agreeableness and Conscientiousness were positively associated with age. Effect sizes comparing…

  16. Stuttering Attitudes among Turkish Family Generations and Neighbors from Representative Samples

    Science.gov (United States)

    Ozdemir, R. Sertan; St. Louis, Kenneth O.; Topbas, Seyhun

    2011-01-01

    Purpose: Attitudes toward stuttering, measured by the "Public Opinion Survey of Human Attributes-Stuttering" ("POSHA-S"), are compared among (a) two different representative samples; (b) family generations (children, parents, and either grandparents or uncles and aunts) and neighbors; (c) children, parents, grandparents/adult…

  17. Investigating sex differences in psychological predictors of snack intake among a large representative sample

    NARCIS (Netherlands)

    Adriaanse, M.A.; Evers, C.; Verhoeven, A.A.C.; de Ridder, D.T.D.

    It is often assumed that there are substantial sex differences in eating behaviour (e.g. women are more likely to be dieters or emotional eaters than men). The present study investigates this assumption in a large representative community sample while incorporating a comprehensive set of

  18. Ethnic Variations of Pathways Linking Socioeconomic Status, Parenting, and Preacademic Skills in a Nationally Representative Sample

    Science.gov (United States)

    Iruka, Iheoma U.; Dotterer, Aryn M.; Pungello, Elizabeth P.

    2014-01-01

    Research Findings: Grounded in the investment model and informed by the integrative theory of the study of minority children, this study used the Early Childhood Longitudinal Study-Birth Cohort data set, a nationally representative sample of young children, to investigate whether the association between socioeconomic status (family income and…

  19. Psychiatric disorders in a representative sample of incarcerated boys in the Netherlands

    NARCIS (Netherlands)

    Vreugdenhil, Coby; Doreleijers, Theo A. H.; Vermeiren, Robert; Wouters, Luuk F. J. M.; van den Brink, Wim

    2004-01-01

    Objective: To determine the prevalence of psychiatric disorders among incarcerated male adolescents and to investigate the influence of psychopathology on allocation to either plain detention or detention with compulsory treatment. Method: A cross-sectional study of a representative sample (N = 204)

  20. Disentangling the Relationship between Child Maltreatment and Violent Delinquency: Using a Nationally Representative Sample

    Science.gov (United States)

    Yun, Ilhong; Ball, Jeremy D.; Lim, Hyeyoung

    2011-01-01

    This study uses the National Longitudinal Study of Adolescents (Add Health) data, a nationally representative sample of adolescents, to disentangle the relationship between child maltreatment and violent delinquency. Also examined are potential moderating effects of gender, socioeconomic status (SES), and religiosity on the association between…

  1. Determination of geostatistically representative sampling locations in Porsuk Dam Reservoir (Turkey)

    Science.gov (United States)

    Aksoy, A.; Yenilmez, F.; Duzgun, S.

    2013-12-01

    Several factors such as wind action, bathymetry and shape of a lake/reservoir, inflows, outflows, point and diffuse pollution sources result in spatial and temporal variations in water quality of lakes and reservoirs. The guides by the United Nations Environment Programme and the World Health Organization to design and implement water quality monitoring programs suggest that even a single monitoring station near the center or at the deepest part of a lake will be sufficient to observe long-term trends if there is good horizontal mixing. In stratified water bodies, several samples can be required. According to the guide of sampling and analysis under the Turkish Water Pollution Control Regulation, a minimum of five sampling locations should be employed to characterize the water quality in a reservoir or a lake. The European Union Water Framework Directive (2000/60/EC) states to select a sufficient number of monitoring sites to assess the magnitude and impact of point and diffuse sources and hydromorphological pressures in designing a monitoring program. Although existing regulations and guidelines include frameworks for the determination of sampling locations in surface waters, most of them do not specify a procedure in establishment of monitoring aims with representative sampling locations in lakes and reservoirs. In this study, geostatistical tools are used to determine the representative sampling locations in the Porsuk Dam Reservoir (PDR). Kernel density estimation and kriging were used in combination to select the representative sampling locations. Dissolved oxygen and specific conductivity were measured at 81 points. Sixteen of them were used for validation. In selection of the representative sampling locations, care was given to keep similar spatial structure in distributions of measured parameters. A procedure was proposed for that purpose. Results indicated that spatial structure was lost under 30 sampling points. This was as a result of varying water

  2. Two-dimensional structure and kinematics of a representative sample of low-z ULIRGs

    International Nuclear Information System (INIS)

    Garcia-Marin, M; Colina, L; Arribas, S

    2008-01-01

    We present the optical INTEGRAL integral field spectroscopy data and Hubble Space Telescope archive images obtained for a representative sample of 22 local Ultraluminous Infrared Galaxies (ULIRGs L IR >10 12 L o-dot ). The sample has been designed for fulfilling a program aimed at studying the internal structure and kinematics of this type of galaxies. Taking advantage of the two-dimensional nature of the data, we study the structure of the stellar and ionized gas, the internal ionization state and the gas kinematics. In this contribution we present the sample and the most important results obtained so far.

  3. Selection of representative calibration sample sets for near-infrared reflectance spectroscopy to predict nitrogen concentration in grasses

    DEFF Research Database (Denmark)

    Shetty, Nisha; Rinnan, Åsmund; Gislum, René

    2012-01-01

    ) algorithm were used and compared. Both Puchwein and CADEX methods provide a calibration set equally distributed in space, and both methods require a minimum prior of knowledge. The samples were also selected randomly using complete random, cultivar random (year fixed), year random (cultivar fixed......) and interaction (cultivar × year fixed) random procedures to see the influence of different factors on sample selection. Puchwein's method performed best with lowest RMSEP followed by CADEX, interaction random, year random, cultivar random and complete random. Out of 118 samples of the complete calibration set...... effectively enhance the cost-effectiveness of NIR spectral analysis by reducing the number of analyzed samples in the calibration set by more than 80%, which substantially reduces the effort of laboratory analyses with no significant loss in prediction accuracy....

  4. Random sampling of evolution time space and Fourier transform processing

    International Nuclear Information System (INIS)

    Kazimierczuk, Krzysztof; Zawadzka, Anna; Kozminski, Wiktor; Zhukov, Igor

    2006-01-01

    Application of Fourier Transform for processing 3D NMR spectra with random sampling of evolution time space is presented. The 2D FT is calculated for pairs of frequencies, instead of conventional sequence of one-dimensional transforms. Signal to noise ratios and linewidths for different random distributions were investigated by simulations and experiments. The experimental examples include 3D HNCA, HNCACB and 15 N-edited NOESY-HSQC spectra of 13 C 15 N labeled ubiquitin sample. Obtained results revealed general applicability of proposed method and the significant improvement of resolution in comparison with conventional spectra recorded in the same time

  5. The prevalence of Nonsuicidal Self-Injury (NSSI in a representative sample of the German population

    Directory of Open Access Journals (Sweden)

    Paul L. Plener

    2016-10-01

    Full Text Available Abstract Background Non-suicidal self-injury (NSSI is a proposed new “condition for further study” in the DSM-5. To date no prevalence data has been available on this diagnostic entity from a representative sample of the general population. Methods A representative sample of the German population (N = 2509, mean age = 48.8 years, SD = 18.1, female 55.4 % completed the NSSI section of the German version of the Self-Injurious Thoughts and Behaviors Interview (SITBI-G. Results A history of NSSI at least once during lifetime was reported by 3.1 % of all participants, with higher lifetime prevalence rates in younger age groups. DSM-5 NSSI disorder criteria were met by 0.3 %. The most common function of NSSI was automatic negative reinforcement (e.g. to alleviate negative feelings. Conclusions To the best of our knowledge, this is the first study reporting rates for the proposed NSSI category in DSM-5 from a representative sample of the general population. In comparison to findings from community samples of adolescents, adults seem to have lower lifetime prevalence rates of NSSI, thus making it necessary to emphasize prevention and treatment efforts in younger age groups.

  6. Adaptive importance sampling of random walks on continuous state spaces

    International Nuclear Information System (INIS)

    Baggerly, K.; Cox, D.; Picard, R.

    1998-01-01

    The authors consider adaptive importance sampling for a random walk with scoring in a general state space. Conditions under which exponential convergence occurs to the zero-variance solution are reviewed. These results generalize previous work for finite, discrete state spaces in Kollman (1993) and in Kollman, Baggerly, Cox, and Picard (1996). This paper is intended for nonstatisticians and includes considerable explanatory material

  7. Video Games Exposure and Sexism in a Representative Sample of Adolescents.

    Science.gov (United States)

    Bègue, Laurent; Sarda, Elisa; Gentile, Douglas A; Bry, Clementine; Roché, Sebastian

    2017-01-01

    Research has indicated that many video games are saturated with stereotypes of women and that these contents may cultivate sexism. The purpose of this study was to assess the relationship between video game exposure and sexism for the first time in a large and representative sample. Our aim was also to measure the strength of this association when two other significant and well-studied sources of sexism, television exposure and religiosity, were also included in a multivariate model. A representative sample of 13520 French youth aged 11-19 years completed a survey measuring weekly video game and television exposure, religiosity, and sexist attitudes toward women. Controlling for gender and socioeconomic level, results showed that video game exposure and religiosity were both related to sexism. Implications of these results for future research on sexism in video games are discussed.

  8. Ordinary or peculiar men? Comparing the customers of prostitutes with a nationally representative sample of men.

    Science.gov (United States)

    Monto, Martin A; Milrod, Christine

    2014-07-01

    Recent media attention implies that prostitution seeking is widespread, an "ordinary" aspect of masculine sexual behavior. Other accounts suggest that customers are "peculiar," characterized by distinct qualities, perversions, or psychological impairments. Using the nationally representative General Social Survey (GSS), this study demonstrates that prostitution seeking is relatively uncommon. Only about 14% of men in the United States report having ever paid for sex, and only 1% report having done so during the previous year. Furthermore, this study dissects whether customers are ordinary or peculiar by comparing a new sample of active customers who solicit sex on the Internet with an older sample of arrested customers, a sample of customers from the GSS, and a nationally representative sample of noncustomers. The customers of Internet sexual service providers differed greatly from men in general and also from other customers. The remaining samples of customers differed slightly from noncustomers in general. We argue for a balanced perspective that recognizes the significant variety among customers. There is no evidence of a peculiar quality that differentiates customers in general from men who have not paid for sex. © The Author(s) 2013.

  9. The Stages of Change in Smoking Cessation in a Representative Sample of Korean Adult Smokers

    OpenAIRE

    Jhun, Hyung-Joon; Seo, Hong-Gwan

    2006-01-01

    This study reports the stages of change in smoking cessation in a representative sample of Korean adult smokers. The study subjects, all adult smokers (n=2,422), were recruited from the second Korea National Health and Nutrition Examination Survey conducted in 2001. The stages of change were categorized using demographic (age and sex), socioeconomic (education, residence, and household income), and smoking characteristics (age at smoking onset, duration of smoking, and number of cigarettes sm...

  10. Socioeconomic Determinants of Bullying in the Workplace: A National Representative Sample in Japan

    OpenAIRE

    Tsuno, Kanami; Kawakami, Norito; Tsutsumi, Akizumi; Shimazu, Akihito; Inoue, Akiomi; Odagiri, Yuko; Yoshikawa, Toru; Haratani, Takashi; Shimomitsu, Teruichi; Kawachi, Ichiro

    2015-01-01

    Bullying in the workplace is an increasingly recognized threat to employee health. We sought to test three hypotheses related to the determinants of workplace bullying: power distance at work; safety climate; and frustration related to perceived social inequality. A questionnaire survey was administered to a nationally representative community-based sample of 5,000 residents in Japan aged 20-60 years. The questionnaire included questions about employment, occupation, company size, education, ...

  11. Predictors of type 2 diabetes in a nationally representative sample of adults with psychosis

    OpenAIRE

    Foley, Debra L; Mackinnon, Andrew; Morgan, Vera A; Watts, Gerald F; McGrath, John J; Castle, David J; Waterreus, Anna; Galletly, Cherrie A

    2014-01-01

    Antipsychotic drugs such as clozapine and olanzapine are associated with an increased risk for type 2 diabetes, but relatively little is known about the relationship between risk factors for type 2 diabetes established in the general population and type 2 diabetes in people with psychosis. We estimated the prevalence of established risk factors and their association with type 2 diabetes in a nationally representative sample of people with an ICD-10 psychosis (N=1642) who gave a fasting blood ...

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

    Science.gov (United States)

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

    2018-01-01

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

  13. 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

  14. 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

  15. Representing Degree Distributions, Clustering, and Homophily in Social Networks With Latent Cluster Random Effects Models.

    Science.gov (United States)

    Krivitsky, Pavel N; Handcock, Mark S; Raftery, Adrian E; Hoff, Peter D

    2009-07-01

    Social network data often involve transitivity, homophily on observed attributes, clustering, and heterogeneity of actor degrees. We propose a latent cluster random effects model to represent all of these features, and we describe a Bayesian estimation method for it. The model is applicable to both binary and non-binary network data. We illustrate the model using two real datasets. We also apply it to two simulated network datasets with the same, highly skewed, degree distribution, but very different network behavior: one unstructured and the other with transitivity and clustering. Models based on degree distributions, such as scale-free, preferential attachment and power-law models, cannot distinguish between these very different situations, but our model does.

  16. Association of post-traumatic stress disorder and obesity in a nationally representative sample.

    Science.gov (United States)

    Pagoto, Sherry L; Schneider, Kristin L; Bodenlos, Jamie S; Appelhans, Bradley M; Whited, Matthew C; Ma, Yunsheng; Lemon, Stephenie C

    2012-01-01

    Recent studies suggest a possible link between post-traumatic stress disorder (PTSD) and obesity risk, which would have implications for the development of obesity-related diseases in this population. The present study examined the association between PTSD and obesity and whether this association differed by sex in a representative sample of the US population. A secondary objective was to determine whether the association between PTSD and obesity was mediated by binge eating disorder (BED). Data were from the Collaborative Psychiatric Epidemiology Surveys (CPES), which comprises three nationally representative cross-sectional surveys that were conducted between 2001 and 2003. Logistic regression analyses weighted to represent the general US adult population were performed. In the total sample of 20,013 participants, rates of obesity were 24.1% for persons without a lifetime history of PTSD and 32.6% among persons with PTSD in the past year. Adjusting for socio-demographic characteristics, depression, substance and alcohol abuse/dependence, and psychotropic medication status, past year PTSD was associated with greater likelihood of obesity (odds ratio (OR) = 1.51; 95% confidence interval (CI) = 1.18, 1.95), with no differences by gender. BED did not statistically mediate the relationship between PTSD and obesity. The present study provides support for a link between PTSD and obesity. Findings further existing literature by indicating that the association is consistent across sexes and is not statistically mediated by BED.

  17. 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.

  18. Symptoms and problems in a nationally representative sample of advanced cancer patients

    DEFF Research Database (Denmark)

    Johnsen, Anna Thit; Petersen, Morten Aagaard; Pedersen, Lise

    2009-01-01

    Little is known about the need for palliative care among advanced cancer patients who are not in specialist palliative care. The purpose was to identify prevalence and predictors of symptoms and problems in a nationally representative sample of Danish advanced cancer patients. Patients with cancer...... or not were associated with several symptoms and problems. This is probably the first nationally representative study of its kind. It shows that advanced cancer patients in Denmark have symptoms and problems that deserve attention and that some patient groups are especially at risk....... predictors. In total, 977 (60%) patients participated. The most frequent symptoms/problems were fatigue (57%; severe 22%) followed by reduced role function, insomnia and pain. Age, cancer stage, primary tumour, type of department, marital status and whether the patient had recently been hospitalized...

  19. Intergenerational Transmission of Marital Violence: Results From a Nationally Representative Sample of Men.

    Science.gov (United States)

    Murshid, Nadine Shaanta; Murshid, Navine

    2015-09-16

    The present study assesses the association between childhood exposure to parental violence and perpetration of marital violence as adults among a representative sample of 3,396 men in Bangladesh. We used secondary analysis of survey data from the nationally representative Bangladesh Demographic and Health Survey 2007 to examine factors associated with perpetration of martial violence among 3,396 ever-married men between the ages of 16 and 50 years. Outcome measure, marital violence perpetration, was measured using a modified Conflict Tactics Scale, and predictor variables included childhood exposure to parental violence, justification of marital violence, marital duration, religion, and demographic variables. Results indicate that marital violence perpetration is significantly associated with childhood exposure to marital violence, suggesting a cycle of violence that is maintained across generations. Implications for policy and practice are discussed. © The Author(s) 2015.

  20. [Anxiety in a representative sample of the Spanish population over 50 years-old].

    Science.gov (United States)

    Carreira Capeáns, Cecilia; Facal, David

    Anxiety is common throughout the ageing process. The objective of this study is to estimate the prevalence of anxiety in a representative sample of the Spanish population over 50 years-old. The data of this study come from the Pilot Study developed within the Longitudinal Ageing Study in Spain (ELES), in which a representative sample of the non-institutionalised Spanish population was evaluated. An analysis was performed on the data of 1086 people who answered the question «I am now going to read a list with a series of diseases or health problems. I would like you to tell me if your doctor has diagnosed any of them». The tools used were a questionnaire consisting of 218 questions, along with standardised tests, such as the Spanish version of the Mini-Mental State Examination. Anxiety was reported to have been diagnosed at some time in 14.3% of the sample. The prevalence was higher in women than in men (77.8 vs. 22.2%), decreasing with age, and related to different chronic diseases. The results show that the prevalence of anxiety throughout the lifespan is noticeable in people over 50 years, and should be taken into account, especially in the female population and in those with chronic diseases. Copyright © 2017 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Personality factors and suicide risk in a representative sample of the German general population.

    Directory of Open Access Journals (Sweden)

    Victor Blüml

    Full Text Available OBJECTIVE: Previous research has shown an association between certain personality characteristics and suicidality. Methodological differences including small sample sizes and missing adjustment for possible confounding factors could explain the varying results. The aim of this study was to assess the impact of the Big Five personality dimensions on suicidality in a representative population based sample of adults. METHOD: Interviews were conducted in a representative German population-based sample (n=2555 in 2011. Personality characteristics were assessed using the Big Five Inventory-10 (BFI-10 and suicide risk was assessed with the Suicidal Behaviors Questionnaire-Revised (SBQ-R. Multivariate logistic regression models were calculated adjusting for depression, anxiety, and various sociodemographic variables. RESULTS: Neuroticism and openness were significantly associated with suicide risk, while extraversion and conscientiousness were found to be protective. Significant sex differences were observed. For males, extraversion and conscientiousness were protective factors. Neuroticism and openness were found to be associated with suicide risk only in females. These associations remained significant after adjusting for covariates. CONCLUSION: The results highlight the role of personality dimensions as risk factors for suicide-related behaviors. Different personality dimensions are significantly associated with suicide-related behaviors even when adjusting for other known risk factors of suicidality.

  2. Recruitment of representative samples for low incidence cancer populations: Do registries deliver?

    Directory of Open Access Journals (Sweden)

    Sanson-Fisher Rob

    2011-01-01

    Full Text Available Abstract Background Recruiting large and representative samples of adolescent and young adult (AYA cancer survivors is important for gaining accurate data regarding the prevalence of unmet needs in this population. This study aimed to describe recruitment rates for AYAs recruited through a cancer registry with particular focus on: active clinician consent protocols, reasons for clinicians not providing consent and the representativeness of the final sample. Methods Adolescents and young adults aged 14 to19 years inclusive and listed on the cancer registry from January 1 2002 to December 31 2007 were identified. An active clinician consent protocol was used whereby the registry sent a letter to AYAs primary treating clinicians requesting permission to contact the survivors. The registry then sent survivors who received their clinician's consent a letter seeking permission to forward their contact details to the research team. Consenting AYAs were sent a questionnaire which assessed their unmet needs. Results The overall consent rate for AYAs identified as eligible by the registry was 7.8%. Of the 411 potentially eligible survivors identified, just over half (n = 232, 56% received their clinician's consent to be contacted. Of those 232 AYAs, 65% were unable to be contacted. Only 18 AYAs (7.8% refused permission for their contact details to be passed on to the research team. Of the 64 young people who agreed to be contacted, 50% (n = 32 completed the questionnaire. Conclusions Cancer registries which employ active clinician consent protocols may not be appropriate for recruiting large, representative samples of AYAs diagnosed with cancer. Given that AYA cancer survivors are highly mobile, alternative methods such as treatment centre and clinic based recruitment may need to be considered.

  3. Association between intimate partner violence and child maltreatment in a representative student sample in Hong Kong.

    Science.gov (United States)

    Chan, Ko Ling

    2015-04-01

    The study examined the prevalence of the co-occurrence of intimate partner violence (IPV) and child maltreatment (CM) to determine whether IPV is a factor associated with the latter. A total of 5,841 students from a representative sample of schools in Hong Kong were surveyed. The results show that the lifetime and preceding-year co-occurrence rates of IPV and CM were 12.3% and 3.6%, respectively. IPV and parents' use of psychological aggression and corporal punishment led to increased odds of physical violence. This study suggests a need for the comprehensive assessment of IPV and CM. © The Author(s) 2015.

  4. Problematic Social Media Use: Results from a Large-Scale Nationally Representative Adolescent Sample.

    Directory of Open Access Journals (Sweden)

    Fanni Bányai

    Full Text Available Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD. Using the Bergen Social Media Addiction Scale (BSMAS and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs.

  5. Problematic Social Media Use: Results from a Large-Scale Nationally Representative Adolescent Sample.

    Science.gov (United States)

    Bányai, Fanni; Zsila, Ágnes; Király, Orsolya; Maraz, Aniko; Elekes, Zsuzsanna; Griffiths, Mark D; Andreassen, Cecilie Schou; Demetrovics, Zsolt

    2017-01-01

    Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs.

  6. Use of psychotherapy in a representative adult community sample in São Paulo, Brazil

    Science.gov (United States)

    Blay, Sergio L.; Fillenbaum, Gerda G.; da Silva, Paula Freitas R.; Peluso, Erica T.

    2014-01-01

    Little is known about the use of psychotherapy to treat common mental disorders in a major city in a middle income country. Data come from in-home interviews with a stratified random sample of 2,000 community residents age 18–65 in the city of São Paulo, Brazil. The information obtained included sociodemographic characteristics; psychotropic drugs; mental status; and lifetime, previous 12 months, and current use of psychotherapy. Logistic regression was used to examine determinants of use of psychotherapy. Of the sample, 22.7% met General Health Questionnaire-12 criteria for common mental disorders. Lifetime, previous 12 months, and current use of psychotherapy were reported by 14.6%, 4.6%, and 2.3% of the sample respectively. Users were typically women, more educated, higher income, not married, unemployed, with common mental disorders. Further analysis found that 47% (with higher education and income) paid out-of-pocket, and 53% used psychotropic medication. Psychotherapy does not appear to be the preferred treatment for common mental disorders. PMID:25118139

  7. Random vs. systematic sampling from administrative databases involving human subjects.

    Science.gov (United States)

    Hagino, C; Lo, R J

    1998-09-01

    Two sampling techniques, simple random sampling (SRS) and systematic sampling (SS), were compared to determine whether they yield similar and accurate distributions for the following four factors: age, gender, geographic location and years in practice. Any point estimate within 7 yr or 7 percentage points of its reference standard (SRS or the entire data set, i.e., the target population) was considered "acceptably similar" to the reference standard. The sampling frame was from the entire membership database of the Canadian Chiropractic Association. The two sampling methods were tested using eight different sample sizes of n (50, 100, 150, 200, 250, 300, 500, 800). From the profile/characteristics, summaries of four known factors [gender, average age, number (%) of chiropractors in each province and years in practice], between- and within-methods chi 2 tests and unpaired t tests were performed to determine whether any of the differences [descriptively greater than 7% or 7 yr] were also statistically significant. The strengths of the agreements between the provincial distributions were quantified by calculating the percent agreements for each (provincial pairwise-comparison methods). Any percent agreement less than 70% was judged to be unacceptable. Our assessments of the two sampling methods (SRS and SS) for the different sample sizes tested suggest that SRS and SS yielded acceptably similar results. Both methods started to yield "correct" sample profiles at approximately the same sample size (n > 200). SS is not only convenient, it can be recommended for sampling from large databases in which the data are listed without any inherent order biases other than alphabetical listing by surname.

  8. Adherence rates to the Mediterranean diet are low in a representative sample of Greek children and adolescents

    NARCIS (Netherlands)

    Kontogianni, Meropi D; Vidra, Nikoletta; Farmaki, Anastasia-Eleni; Koinaki, Stella; Belogianni, Katerina; Sofrona, Stavroula; Magkanari, Flora; Yannakoulia, Mary

    2008-01-01

    Data from studies in pediatric samples exploring adherence to the Mediterranean diet are scarce. The aim of the present work was to explore adherence to a Mediterranean diet pattern in a representative sample of Greek children and adolescents. The study sample (n = 1305, 3-18 y) was representative

  9. Applying an Occupational Classification to a National Representative Sample of Work Histories of Young Men and Women.

    Science.gov (United States)

    Nafziger, Dean H.; And Others

    Holland's occupational classification was used to analyze the work histories of a national representative sample of young men and women age 14-24. This study extended previous tests of the classification in three ways: (1) It was applied for the first time to a national, representative sample of women, (2) For the sample of men, 3-year…

  10. Viewing child pornography: prevalence and correlates in a representative community sample of young Swedish men.

    Science.gov (United States)

    Seto, Michael C; Hermann, Chantal A; Kjellgren, Cecilia; Priebe, Gisela; Svedin, Carl Göran; Långström, Niklas

    2015-01-01

    Most research on child pornography use has been based on selected clinical or criminal justice samples; risk factors for child pornography use in the general population remain largely unexplored. In this study, we examined prevalence, risk factors, and correlates of viewing depictions of adult-child sex in a population-representative sample of 1,978 young Swedish men (17-20 years, Mdn = 18 years, overall response rate, 77 %). In an anonymous, school-based survey, participants self-reported sexual coercion experiences, attitudes and beliefs about sex, perceived peer attitudes, and sexual interests and behaviors; including pornography use, sexual interest in children, and sexually coercive behavior. A total of 84 (4.2 %) young men reported they had ever viewed child pornography. Most theory-based variables were moderately and significantly associated with child pornography viewing and were consistent with models of sexual offending implicating both antisociality and sexual deviance. In multivariate logistic regression analysis, 7 of 15 tested factors independently predicted child pornography viewing and explained 42 % of the variance: ever had sex with a male, likely to have sex with a child aged 12-14, likely to have sex with a child 12 or less, perception of children as seductive, having friends who have watched child pornography, frequent pornography use, and ever viewed violent pornography. From these, a 6-item Child Pornography Correlates Scale was constructed and then cross-validated in a similar but independent Norwegian sample.

  11. Structure-based Markov random field model for representing evolutionary constraints on functional sites.

    Science.gov (United States)

    Jeong, Chan-Seok; Kim, Dongsup

    2016-02-24

    Elucidating the cooperative mechanism of interconnected residues is an important component toward understanding the biological function of a protein. Coevolution analysis has been developed to model the coevolutionary information reflecting structural and functional constraints. Recently, several methods have been developed based on a probabilistic graphical model called the Markov random field (MRF), which have led to significant improvements for coevolution analysis; however, thus far, the performance of these models has mainly been assessed by focusing on the aspect of protein structure. In this study, we built an MRF model whose graphical topology is determined by the residue proximity in the protein structure, and derived a novel positional coevolution estimate utilizing the node weight of the MRF model. This structure-based MRF method was evaluated for three data sets, each of which annotates catalytic site, allosteric site, and comprehensively determined functional site information. We demonstrate that the structure-based MRF architecture can encode the evolutionary information associated with biological function. Furthermore, we show that the node weight can more accurately represent positional coevolution information compared to the edge weight. Lastly, we demonstrate that the structure-based MRF model can be reliably built with only a few aligned sequences in linear time. The results show that adoption of a structure-based architecture could be an acceptable approximation for coevolution modeling with efficient computation complexity.

  12. RandomSpot: A web-based tool for systematic random sampling of virtual slides.

    Science.gov (United States)

    Wright, Alexander I; Grabsch, Heike I; Treanor, Darren E

    2015-01-01

    This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Systematic random sampling (SRS) is a stereological tool, which provides a framework to quickly build an accurate estimation of the distribution of objects or classes within an image, whilst minimizing the number of observations required. RandomSpot is a web-based tool for SRS in stereology, which systematically places equidistant points within a given region of interest on a virtual slide. Each point can then be visually inspected by a pathologist in order to generate an unbiased sample of the distribution of classes within the tissue. Further measurements can then be derived from the distribution, such as the ratio of tumor to stroma. RandomSpot replicates the fundamental principle of traditional light microscope grid-shaped graticules, with the added benefits associated with virtual slides, such as facilitated collaboration and automated navigation between points. Once the sample points have been added to the region(s) of interest, users can download the annotations and view them locally using their virtual slide viewing software. Since its introduction, RandomSpot has been used extensively for international collaborative projects, clinical trials and independent research projects. So far, the system has been used to generate over 21,000 sample sets, and has been used to generate data for use in multiple publications, identifying significant new prognostic markers in colorectal, upper gastro-intestinal and breast cancer. Data generated using RandomSpot also has significant value for training image analysis algorithms using sample point coordinates and pathologist classifications.

  13. Pathological narcissism and maladaptive self-regulatory behaviours in a nationally representative sample of Canadian men.

    Science.gov (United States)

    Kealy, David; Ogrodniczuk, John S; Rice, Simon M; Oliffe, John L

    2017-10-01

    Clinical observation has linked externalizing coping strategies such as substance overuse and aggressive behaviours with narcissistic personality dysfunction. This study examined the relationship between pathological narcissism and maladaptive self-regulatory behaviours among Canadian men. An online survey was distributed among a stratified, nationally representative sample of 1000 men from across Canada. The survey included brief self-report measures of pathological narcissism, maladaptive externalizing coping behaviours, and general psychological distress. After controlling for the effects of age and general psychological distress, pathological narcissism was found to be significantly associated with alcohol overuse and aggressive behaviour. Significant though modest interaction effects were found between pathological narcissism and age - with regards to drug use - and distress - with regards to risk-taking behaviour. The findings point to the need for attention to narcissistic dysfunction as a clinical and public health issue among men. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Attention-Deficit/Hyperactivity Disorder Symptoms and Life Satisfaction in a Representative Adolescent and Adult Sample.

    Science.gov (United States)

    Hennig, Timo; Koglin, Ute; Schmidt, Sören; Petermann, Franz; Brähler, Elmar

    2017-09-01

    Although it is well documented that attention-deficit/hyperactivity disorder (ADHD) is associated with reduced life satisfaction, the mechanisms that might explain this co-occurrence are unclear. We examined the correlation of ADHD symptoms with life satisfaction and whether this association is mediated by (lacking) social support and depressive symptoms. Self-reported ADHD symptoms, life satisfaction, social support, and depressive symptoms were assessed in a representative, predominantly adult sample from the general population (14-91 years, N = 2517). Attention-deficit/hyperactivity disorder symptoms correlated negatively with life satisfaction (r = -0.41, p life satisfaction. Counteracting problems with social relationships and treating depressive symptoms may help to increase life satisfaction in adults with ADHD symptoms.

  15. Satisfaction with life scale in a representative sample of Spanish adults: validation and normative data.

    Science.gov (United States)

    Vázquez, Carmelo; Duque, Almudena; Hervás, Gonzalo

    2013-01-01

    The Satisfaction with Life Scale (SWLS) is a measure widely used to assess life satisfaction. This paper aims to test its psychometric properties, factor structure, and distribution scores across age, gender, education, and employment status. For this purpose, a representative sample of the Spanish population (N = 2,964) was used. Although analyses showed no significant differences across age or gender, participants with higher education level and those who held an occupation were more satisfied with their lives. Confirmatory factor analysis revealed a unifactorial structure with significant correlations between the SWLS, and subjective happiness and social support. The internal consistency of the scale was .88. Thus, our results indicate that the Spanish version of the SWLS is a valid and reliable measure of life satisfaction within the Spanish context.

  16. Sexual orientation and future parenthood in a 2011-2013 nationally representative United States sample.

    Science.gov (United States)

    Riskind, Rachel G; Tornello, Samantha L

    2017-09-01

    Previous researchers have found evidence for differences in parenting goals between lesbian and gay people and their heterosexual peers. However, no previous research has quantified the parenting goals of bisexual people or evaluated parenting goals as a function of sexual partner gender. In addition, political and social climates for sexual minority people had improved rapidly since the last representative data on lesbian and gay peoples' plans for parenthood were collected. We analyzed data from 3,941 childless lesbian, gay, bisexual, and heterosexual participants from the 2011-2013 National Survey of Family Growth (NSFG; United States Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics, 2014), a nationally representative sample of United States residents aged 15 to 44 years. We found that statistically significant, within-gender sexual orientation differences in parenting plans persist, despite social and legal changes. Consistent with hypotheses, bisexual men's parenting desires and intentions were similar to those of their heterosexual male peers and different from those of their gay male peers, while bisexual women's reports were more mixed. Also consistent with hypotheses, the gender of the most recent sexual partner was a strong predictor of parenting goals. We discuss implications for mental and reproductive health-care providers, attorneys, social workers, and others who interact with sexual minority adults. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. Sexuality education in a representative sample of Portuguese schools: examining the impact of legislation.

    Science.gov (United States)

    Rocha, Ana Cristina; Duarte, Cidália

    2015-02-01

    To share Portugal's experience with school-based sexuality education, and to describe its implementation at a local level, following an ecological model and using a mixed methodology approach. The study also examines the impact of the latest policies put into effect, identifying potential weaknesses and strengths affecting the effectiveness of sexuality education enforcement. A representative sample of 296 schools in Portugal was analysed. Teachers representing the school completed a questionnaire and were asked to share any kind of official document from their sexuality education project (such as curriculum content). A subsample of these documents was analysed by two coders. Quantitative analysis was carried out using descriptive statistics. The majority of Portuguese schools delivered sexuality education, in line with Portuguese technical guidelines and international recommendations. There were common procedures in planning, implementation and evaluation of sexuality education. Some strengths and weaknesses were identified. Results highlighted the impact of the various systems on the planning, enforcement and evaluation of sexuality education in school. The latest policies introduced valuable changes in school-based sexuality education. A way of assessing effectiveness of sexuality education is still needed.

  18. Relationship of personality disorders to the course of major depressive disorder in a nationally representative sample.

    Science.gov (United States)

    Skodol, Andrew E; Grilo, Carlos M; Keyes, Katherine M; Geier, Timothy; Grant, Bridget F; Hasin, Deborah S

    2011-03-01

    The purpose of this study was to examine the effects of specific personality disorder comorbidity on the course of major depressive disorder in a nationally representative sample. Data were drawn from 1,996 participants in a national survey. Participants who met criteria for major depressive disorder at baseline in face-to-face interviews (in 2001-2002) were reinterviewed 3 years later (in 2004-2005) to determine persistence and recurrence. Predictors included all DSM-IV personality disorders. Control variables included demographic characteristics, other axis I disorders, family and treatment histories, and previously established predictors of the course of major depressive disorder. A total of 15.1% of participants had persistent major depressive disorder, and 7.3% of those who remitted had a recurrence. Univariate analyses indicated that avoidant, borderline, histrionic, paranoid, schizoid, and schizotypal personality disorders all elevated the risk for persistence. With axis I comorbidity controlled, all personality disorders except histrionic personality disorder remained significant. With all other personality disorders controlled, borderline and schizotypal disorders remained significant predictors. In final, multivariate analyses that controlled for age at onset of major depressive disorder, the number of previous episodes, duration of the current episode, family history, and treatment, borderline personality disorder remained a robust predictor of major depressive disorder persistence. Neither personality disorders nor other clinical variables predicted recurrence. In this nationally representative sample of adults with major depressive disorder, borderline personality disorder robustly predicted persistence, a finding that converges with recent clinical studies. Personality psychopathology, particularly borderline personality disorder, should be assessed in all patients with major depressive disorder, considered in prognosis, and addressed in treatment.

  19. Illicit drug use among rave attendees in a nationally representative sample of US high school seniors.

    Science.gov (United States)

    Palamar, Joseph J; Griffin-Tomas, Marybec; Ompad, Danielle C

    2015-07-01

    The popularity of electronic dance music and rave parties such as dance festivals has increased in recent years. Targeted samples of party-goers suggest high rates of drug use among attendees, but few nationally representative studies have examined these associations. We examined sociodemographic correlates of rave attendance and relationships between rave attendance and recent (12-month) use of various drugs in a representative sample of US high school seniors (modal age: 18) from the Monitoring the Future study (2011-2013; Weighted N=7373). One out of five students (19.8%) reported ever attending a rave, and 7.7% reported attending at least monthly. Females and highly religious students were less likely to attend raves, and Hispanics, students residing in cities, students with higher income and those who go out for fun multiple times per week were more likely to attend. Rave attendees were more likely than non-attendees to report use of an illicit drug other than marijuana (35.5% vs. 15.6%, p<0.0001). Attendees were more likely to report use of each of the 18 drugs assessed, and attendees were more likely to report more frequent use (≥6 times) of each drug (ps<0.0001). Controlling for sociodemographic covariates, frequent attendance (monthly or more often) was associated with higher odds of use of each drug (ps<0.0001). Frequent attendees were at highest risk for use of "club drugs." Findings from this study can help inform prevention and harm reduction among rave attendees at greatest risk for drug use. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Relationship of Personality Disorders to the Course of Major Depressive Disorder in a Nationally Representative Sample

    Science.gov (United States)

    Skodol, Andrew E.; Grilo, Carlos M.; Keyes, Katherine; Geier, Timothy; Grant, Bridget F.; Hasin, Deborah S.

    2011-01-01

    Objective The purpose of this study was to examine the effects of specific personality disorder co-morbidity on the course of major depressive disorder in a nationally-representative sample. Method Data were drawn from 1,996 participants in a national survey. Participants who met criteria for major depressive disorder at baseline in face-to-face interviews (2001–2002) were re-interviewed three years later (2004–2005) to determine persistence and recurrence. Predictors included all DSM-IV personality disorders. Control variables included demographic characteristics, other Axis I disorders, family and treatment histories, and previously established predictors of the course of major depressive disorder. Results 15.1% of participants had persistent major depressive disorder and 7.3% of those who remitted had a recurrence. Univariate analyses indicated that avoidant, borderline, histrionic, paranoid, schizoid, and schizotypal personality disorders all elevated the risk for persistence. With Axis I co-morbidity controlled, all but histrionic personality disorder remained significant. With all other personality disorders controlled, borderline and schizotypal remained significant predictors. In final, multivariate analyses that controlled for age at onset of major depressive disorder, number of previous episodes, duration of current episode, family history, and treatment, borderline personality disorder remained a robust predictor of major depressive disorder persistence. Neither personality disorders nor other clinical variables predicted recurrence. Conclusions In this nationally-representative sample of adults with major depressive disorder, borderline personality disorder robustly predicted persistence, a finding that converges with recent clinical studies. Personality psychopathology, particularly borderline personality disorder, should be assessed in all patients with major depressive disorder, considered in prognosis, and addressed in treatment. PMID:21245088

  1. Quantitative analysis of nano-pore geomaterials and representative sampling for digital rock physics

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    Yoon, H.; Dewers, T. A.

    2014-12-01

    Geomaterials containing nano-pores (e.g., shales and carbonate rocks) have become increasingly important for emerging problems such as unconventional gas and oil resources, enhanced oil recovery, and geologic storage of CO2. Accurate prediction of coupled geophysical and chemical processes at the pore scale requires realistic representation of pore structure and topology. This is especially true for chalk materials, where pore networks are small and complex, and require characterization at sub-micron scale. In this work, we apply laser scanning confocal microscopy to characterize pore structures and microlithofacies at micron- and greater scales and dual focused ion beam-scanning electron microscopy (FIB-SEM) for 3D imaging of nanometer-to-micron scale microcracks and pore distributions. With imaging techniques advanced for nano-pore characterization, a problem of scale with FIB-SEM images is how to take nanometer scale information and apply it to the thin-section or larger scale. In this work, several texture characterization techniques including graph-based spectral segmentation, support vector machine, and principal component analysis are applied for segmentation clusters represented by 1-2 FIB-SEM samples per each cluster. Geometric and topological properties are analyzed and lattice-Boltzmann method (LBM) is used to obtain permeability at several different scales. Upscaling of permeability to the Darcy scale (e.g., the thin-section scale) with image dataset will be discussed with emphasis on understanding microfracture-matrix interaction, representative volume for FIB-SEM sampling, and multiphase flow and reactive transport. Funding from the DOE Basic Energy Sciences Geosciences Program is gratefully acknowledged. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under

  2. Sex differences in the association between perceived stress and adiposity in a nationally representative sample.

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    Suglia, Shakira F; Pamplin, John R; Forde, Allana T; Shelton, Rachel C

    2017-10-01

    Prior studies examining the association between perceived stress and adiposity have reported mixed findings, and sex differences have largely not been examined. We examined the relationship between perceived stress and body mass index (BMI) and waist circumference in young adults in the National Longitudinal Study of Adolescent to Adult Health. Participants (mean age 29 years; N = 14,044) completed the short form of Cohen's Perceived Stress Scale during a home visit. Height, weight, and waist circumference were assessed during the same visit. BMI was calculated based on measured height and weight. In the sample, 52% were male and 65% were identified as white. In adjusted linear regression analyses, a sex by Perceived Stress Scale interaction was noted (P stress was statistically significantly associated with lower BMI (β: -0.09; standard error [SE]: 0.05) and was associated with lower waist circumference, although not statistically significant (β: -0.18; SE: 0.10) among men. No associations were noted among women. In this nationally representative sample of young adults, perceived stress was associated with lower levels of adiposity among men. Noted differences could be attributed to different behavioral and coping strategies in response to stress between men and women as well as biological mechanisms which should be explored further. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Walking, body mass index, and self-rated health in a representative sample of Spanish adults

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    Vicente Romo-Perez

    2016-01-01

    Full Text Available Abstract Obesity and physical inactivity (PI are risk factors for chronic diseases and are associated with lifestyle and environmental factors. The study tested the association between PI, body mass index (BMI, and self-rated health in a representative sample of the Spanish adult population (N = 21,486. The sample included 41.5% men, with mean age 52.3 years (± 18.03, and age range 20-82 years. Prevalence of overweight/obesity was 34.2%/12.7% in women and 52.1%/12.7% in men (p < 0.001 for obesity in both sexes. 53% of women and 57.5% of men met recommended levels of physical activity by walking (≥ 150 minutes/week. According to logistic regression analysis, individuals that walked less had higher risk of overweight or obesity. Data from the population-based surveillance study support suggestions that regular walking by adults is associated with positive self-rated health and better BMI profile. Obesity and low/very low self-rated health have low prevalence rates to meet the recommendations.

  4. Prevalence and Predictors of Bullying Behavior among Overweight and Obese Youth in a Nationally Representative Sample.

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    Odar Stough, Cathleen; Merianos, Ashley; Nabors, Laura; Peugh, James

    2016-08-01

    Child and adolescent overweight and obesity are independent risk factors for poor social outcomes. Whether children who are overweight display greater bullying behaviors than normal weight peers, controlling for demographic and other social-ecological factors, was examined. The influence of child (e.g., mental health), family (e.g., income, parent mental health, and exposure to domestic violence), and community (e.g., exposure to neighborhood violence, unfair treatment based on race or ethnic group) factors on bullying risk in the subset of children who are overweight and obese was explored. We conducted a secondary data analysis of the 2011-2012 National Survey of Children's Health, a cross-sectional study providing a nationally representative sample of participants, using a series of multinomial logistic regressions in Mplus software (Muthén & Muthén, Los Angeles, CA). Participants were 41,361 youth ages 10-17 years. Despite statistically significant differences in unadjusted analyses, no differences were found in bullying behavior by weight status once controlling for other factors. Child, family, and neighborhood factors predicted bullying behavior in both the overall sample and the subset of overweight and obese youth. However, some risk factors were unique to children who were overweight or obese. Children who are overweight or obese are not at greater risk for engaging in bullying behavior than normal weight peers. Health professionals targeting bullying behavior should be aware of the impact child, family, and neighborhood factors have on bullying by overweight and obese children and adolescents.

  5. Detecting representative data and generating synthetic samples to improve learning accuracy with imbalanced data sets.

    Directory of Open Access Journals (Sweden)

    Der-Chiang Li

    Full Text Available It is difficult for learning models to achieve high classification performances with imbalanced data sets, because with imbalanced data sets, when one of the classes is much larger than the others, most machine learning and data mining classifiers are overly influenced by the larger classes and ignore the smaller ones. As a result, the classification algorithms often have poor learning performances due to slow convergence in the smaller classes. To balance such data sets, this paper presents a strategy that involves reducing the sizes of the majority data and generating synthetic samples for the minority data. In the reducing operation, we use the box-and-whisker plot approach to exclude outliers and the Mega-Trend-Diffusion method to find representative data from the majority data. To generate the synthetic samples, we propose a counterintuitive hypothesis to find the distributed shape of the minority data, and then produce samples according to this distribution. Four real datasets were used to examine the performance of the proposed approach. We used paired t-tests to compare the Accuracy, G-mean, and F-measure scores of the proposed data pre-processing (PPDP method merging in the D3C method (PPDP+D3C with those of the one-sided selection (OSS, the well-known SMOTEBoost (SB study, and the normal distribution-based oversampling (NDO approach, and the proposed data pre-processing (PPDP method. The results indicate that the classification performance of the proposed approach is better than that of above-mentioned methods.

  6. Investigating sex differences in psychological predictors of snack intake among a large representative sample.

    Science.gov (United States)

    Adriaanse, Marieke A; Evers, Catharine; Verhoeven, Aukje A C; de Ridder, Denise T D

    2016-03-01

    It is often assumed that there are substantial sex differences in eating behaviour (e.g. women are more likely to be dieters or emotional eaters than men). The present study investigates this assumption in a large representative community sample while incorporating a comprehensive set of psychological eating-related variables. A community sample was employed to: (i) determine sex differences in (un)healthy snack consumption and psychological eating-related variables (e.g. emotional eating, intention to eat healthily); (ii) examine whether sex predicts energy intake from (un)healthy snacks over and above psychological variables; and (iii) investigate the relationship between psychological variables and snack intake for men and women separately. Snack consumption was assessed with a 7d snack diary; the psychological eating-related variables with questionnaires. Participants were members of an Internet survey panel that is based on a true probability sample of households in the Netherlands. Men and women (n 1292; 45 % male), with a mean age of 51·23 (sd 16·78) years and a mean BMI of 25·62 (sd 4·75) kg/m2. Results revealed that women consumed more healthy and less unhealthy snacks than men and they scored higher than men on emotional and restrained eating. Women also more often reported appearance and health-related concerns about their eating behaviour, but men and women did not differ with regard to external eating or their intentions to eat more healthily. The relationships between psychological eating-related variables and snack intake were similar for men and women, indicating that snack intake is predicted by the same variables for men and women. It is concluded that some small sex differences in psychological eating-related variables exist, but based on the present data there is no need for interventions aimed at promoting healthy eating to target different predictors according to sex.

  7. Modeling Optimal Cutoffs for the Brazilian Household Food Insecurity Measurement Scale in a Nationwide Representative Sample.

    Science.gov (United States)

    Interlenghi, Gabriela S; Reichenheim, Michael E; Segall-Corrêa, Ana M; Pérez-Escamilla, Rafael; Moraes, Claudia L; Salles-Costa, Rosana

    2017-07-01

    Background: This is the second part of a model-based approach to examine the suitability of the current cutoffs applied to the raw score of the Brazilian Household Food Insecurity Measurement Scale [Escala Brasileira de Insegurança Alimentar (EBIA)]. The approach allows identification of homogeneous groups who correspond to severity levels of food insecurity (FI) and, by extension, discriminant cutoffs able to accurately distinguish these groups. Objective: This study aims to examine whether the model-based approach for identifying optimal cutoffs first implemented in a local sample is replicated in a countrywide representative sample. Methods: Data were derived from the Brazilian National Household Sample Survey of 2013 ( n = 116,543 households). Latent class factor analysis (LCFA) models from 2 to 5 classes were applied to the scale's items to identify the number of underlying FI latent classes. Next, identification of optimal cutoffs on the overall raw score was ascertained from these identified classes. Analyses were conducted in the aggregate data and by macroregions. Finally, model-based classifications (latent classes and groupings identified thereafter) were contrasted to the traditionally used classification. Results: LCFA identified 4 homogeneous groups with a very high degree of class separation (entropy = 0.934-0.975). The following cutoffs were identified in the aggregate data: between 1 and 2 (1/2), 5 and 6 (5/6), and 10 and 11 (10/11) in households with children and/or adolescents category emerged consistently in all analyses. Conclusions: Nationwide findings corroborate previous local evidence that households with an overall score of 1 are more akin to those scoring negative on all items. These results may contribute to guide experts' and policymakers' decisions on the most appropriate EBIA cutoffs. © 2017 American Society for Nutrition.

  8. CONSISTENCY UNDER SAMPLING OF EXPONENTIAL RANDOM GRAPH MODELS.

    Science.gov (United States)

    Shalizi, Cosma Rohilla; Rinaldo, Alessandro

    2013-04-01

    The growing availability of network data and of scientific interest in distributed systems has led to the rapid development of statistical models of network structure. Typically, however, these are models for the entire network, while the data consists only of a sampled sub-network. Parameters for the whole network, which is what is of interest, are estimated by applying the model to the sub-network. This assumes that the model is consistent under sampling , or, in terms of the theory of stochastic processes, that it defines a projective family. Focusing on the popular class of exponential random graph models (ERGMs), we show that this apparently trivial condition is in fact violated by many popular and scientifically appealing models, and that satisfying it drastically limits ERGM's expressive power. These results are actually special cases of more general results about exponential families of dependent random variables, which we also prove. Using such results, we offer easily checked conditions for the consistency of maximum likelihood estimation in ERGMs, and discuss some possible constructive responses.

  9. Under-five mortality among mothers employed in agriculture: findings from a nationally representative sample.

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    Singh, Rajvir; Tripathi, Vrijesh

    2015-01-01

    Background. India accounts for 24% to all under-five mortality in the world. Residence in rural area, poverty and low levels of mother's education are known confounders of under-five mortality. Since two-thirds of India's population lives in rural areas, mothers employed in agriculture present a particularly vulnerable population in the Indian context and it is imperative that concerns of this sizeable population are addressed in order to achieve MDG4 targets of reducing U5MR to fewer than 41 per 1,000 by 2015. This study was conducted to examine factors associated with under-five mortality among mothers employed in agriculture. Methods. Data was retrieved from National Family Household Survey-3 in India (2008). The study population is comprised of a national representative sample of single children aged 0 to 59 months and born to mothers aged 15 to 49 years employed in agriculture from all 29 states of India. Univariate and Multivariate Cox PH regression analysis was used to analyse the Hazard Rates of mortality. The predictive power of child mortality among mothers employed in agriculture was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Results. An increase in mothers' ages corresponds with a decrease in child mortality. Breastfeeding reduces child mortality by 70% (HR 0.30, 0.25-0.35, p = 0.001). Standard of Living reduces child mortality by 32% with high standard of living (HR 0.68, 0.52-0.89, 0.001) in comparison to low standard of living. Prenatal care (HR 0.40, 0.34-0.48, p = 0.001) and breastfeeding health nutrition education (HR 0.45, 0.31-0.66, p = 0.001) are associated significant factors for child mortality. Birth Order five is a risk factor for mortality (HR 1.49, 1.05-2.10, p = 0.04) in comparison to Birth Order one among women engaged in agriculture while the household size (6-10 members and ≥ 11 members) is significant in reducing child mortality in comparison to ≤5 members in the house. Under

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

    Science.gov (United States)

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

    2012-09-15

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

  11. Iron status and its determinants in a nationally representative sample of pregnant women.

    Science.gov (United States)

    Vandevijvere, Stefanie; Amsalkhir, Sihame; Van Oyen, Herman; Egli, Ines; Ines, Egli; Moreno-Reyes, Rodrigo

    2013-05-01

    Iron-deficiency anemia is associated with adverse neonatal health outcomes. Iron status and its determinants were assessed in a representative sample of Belgian pregnant women. Blood samples were collected and a questionnaire was completed face-to-face. Hemoglobin (Hb) and mean cell volume were measured using a Beckman Coulter Hematology Analyzer and serum ferritin (SF) and transferrin receptor (sTfr) concentrations by immunoassay. In total, 55 obstetric clinics and 1,311 pregnant women were included. Approximately 40% of third-trimester and 6% of first-trimester women had SF levels less than 15 μg/L. Approximately 21% of third-trimester and 4% of first-trimester women had anemia (Hb 8.5 mg/L). The median body iron stores were 8.1 mg/kg among first-trimester women, but only 3.6 mg/kg among third-trimester women. SF levels were significantly positively associated with age and education level, and were higher among nulliparous women and lower among North-African women. sTfr concentrations were significantly negatively associated with age and were lower among smokers, nulliparous women, and women who planned their pregnancy. Despite the fact that two thirds of Belgian pregnant women took iron-containing supplements, iron deficiency and iron-deficiency anemia were frequent in third-trimester women. The World Health Organization regards this as a moderate public health problem. National iron supplementation guidelines are needed in Belgium to optimize iron status during pregnancy. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  12. Socioeconomic determinants of bullying in the workplace: a national representative sample in Japan.

    Science.gov (United States)

    Tsuno, Kanami; Kawakami, Norito; Tsutsumi, Akizumi; Shimazu, Akihito; Inoue, Akiomi; Odagiri, Yuko; Yoshikawa, Toru; Haratani, Takashi; Shimomitsu, Teruichi; Kawachi, Ichiro

    2015-01-01

    Bullying in the workplace is an increasingly recognized threat to employee health. We sought to test three hypotheses related to the determinants of workplace bullying: power distance at work; safety climate; and frustration related to perceived social inequality. A questionnaire survey was administered to a nationally representative community-based sample of 5,000 residents in Japan aged 20-60 years. The questionnaire included questions about employment, occupation, company size, education, household income, and subjective social status (SSS). We inquired about both the witnessing and personal experience of workplace bullying during the past 30 days. Among 2,384 respondents, data were analyzed from 1,546 workers. Multiple logistic regression analyses were used to examine the social determinants of workplace bullying. Six percent and 15 percent of the total sample reported experiencing or witnessing workplace bullying, respectively. After adjusting for gender and age, temporary employees (Odds Ratio [OR]: 2.45 [95% Confidence Interval (CI) = 1.03-5.85]), junior high school graduates (OR: 2.62 [95%CI: 1.01-6.79]), workers with lowest household income (OR: 4.13 [95%CI:1.58-10.8]), and workers in the lowest SSS stratum (OR: 4.21 [95%CI:1.66-10.7]) were at increased risk of experiencing workplace bullying. When all variables were entered simultaneously in the model, a significant inverse association was observed between higher SSS and experiencing bullying (p = 0.002). Similarly in terms of witnessing bullying; SSS was significantly inversely associated (p = 0.017) while temporary employees reported a significantly higher risk of witnessing bullying compared to permanent workers (OR: 2.25 [95%CI:1.04 to 4.87]). The significant association between SSS and experiencing/witnessing workplace bullying supports the frustration hypothesis. The power distance hypothesis was also partly supported by the finding that temporary employees experienced a higher prevalence of

  13. Socioeconomic determinants of bullying in the workplace: a national representative sample in Japan.

    Directory of Open Access Journals (Sweden)

    Kanami Tsuno

    Full Text Available Bullying in the workplace is an increasingly recognized threat to employee health. We sought to test three hypotheses related to the determinants of workplace bullying: power distance at work; safety climate; and frustration related to perceived social inequality. A questionnaire survey was administered to a nationally representative community-based sample of 5,000 residents in Japan aged 20-60 years. The questionnaire included questions about employment, occupation, company size, education, household income, and subjective social status (SSS. We inquired about both the witnessing and personal experience of workplace bullying during the past 30 days. Among 2,384 respondents, data were analyzed from 1,546 workers. Multiple logistic regression analyses were used to examine the social determinants of workplace bullying. Six percent and 15 percent of the total sample reported experiencing or witnessing workplace bullying, respectively. After adjusting for gender and age, temporary employees (Odds Ratio [OR]: 2.45 [95% Confidence Interval (CI = 1.03-5.85], junior high school graduates (OR: 2.62 [95%CI: 1.01-6.79], workers with lowest household income (OR: 4.13 [95%CI:1.58-10.8], and workers in the lowest SSS stratum (OR: 4.21 [95%CI:1.66-10.7] were at increased risk of experiencing workplace bullying. When all variables were entered simultaneously in the model, a significant inverse association was observed between higher SSS and experiencing bullying (p = 0.002. Similarly in terms of witnessing bullying; SSS was significantly inversely associated (p = 0.017 while temporary employees reported a significantly higher risk of witnessing bullying compared to permanent workers (OR: 2.25 [95%CI:1.04 to 4.87]. The significant association between SSS and experiencing/witnessing workplace bullying supports the frustration hypothesis. The power distance hypothesis was also partly supported by the finding that temporary employees experienced a higher prevalence

  14. Internet Gaming Disorder Among Slovenian Primary Schoolchildren: Findings From a Nationally Representative Sample of Adolescents

    Science.gov (United States)

    Pontes, Halley M.; Macur, Mirna; Griffiths, Mark D.

    2016-01-01

    Background and aims Since the inclusion of Internet Gaming Disorder (IGD) in the latest (fifth) edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a tentative disorder, a few psychometric screening instruments have been developed to assess IGD, including the 9-item Internet Gaming Disorder Scale – Short-Form (IGDS9-SF) – a short, valid, and reliable instrument. Methods Due to the lack of research on IGD in Slovenia, this study aimed to examine the psychometric properties of the IGDS9-SF in addition to investigating the prevalence rates of IGD in a nationally representative sample of eighth graders from Slovenia (N = 1,071). Results The IGDS9-SF underwent rigorous psychometric scrutiny in terms of validity and reliability. Construct validation was investigated with confirmatory factor analysis to examine the factorial structure of the IGDS9-SF and a unidimensional structure appeared to fit the data well. Concurrent and criterion validation were also investigated by examining the association between IGD and relevant psychosocial and game-related measures, which warranted these forms of validity. In terms of reliability, the Slovenian version IGDS9-SF obtained excellent results regarding its internal consistency at different levels, and the test appears to be a valid and reliable instrument to assess IGD among Slovenian youth. Finally, the prevalence rates of IGD were found to be around 2.5% in the whole sample and 3.1% among gamers. Discussion and conclusion Taken together, these results illustrate the suitability of the IGDS9-SF and warrants further research on IGD in Slovenia. PMID:27363464

  15. Internet Addiction Among Elementary and Middle School Students in China: A Nationally Representative Sample Study

    Science.gov (United States)

    Li, Yajun; Zhang, Xinghui; Lu, Furong; Zhang, Qin

    2014-01-01

    Abstract The purpose of this study was to examine the prevalence of Internet addiction in a nationally representative sample of Chinese elementary and middle school students and to investigate Internet addiction among Internet users with different usages. The data were from the National Children's Study of China (NCSC) in which 24,013 fourth- to ninth-grade students were recruited from 100 counties in 31 provinces in China. Only 54.2% of the students had accessed the Internet. According to the criteria of Young's Diagnostic Questionnaire (YDQ), an eight-item instrument, the prevalence of Internet addiction in the total sample was 6.3%, and among Internet users was 11.7%. Among the Internet users, males (14.8%) and rural students (12.1%) reported Internet addiction more than females (7.0%) and urban students (10.6%). The percentage of Internet addicts in elementary school students (11.5%) was not significantly lower than the percentage of middle school students (11.9%). There was no statistically significant difference between the four geographical regions (9.6%, 11.5%, 12.3%, 11.1%) characterized by different levels of economy, health, education, and social environment. As the frequency of Internet use and time spent online per week increased, the percentage of Internet addicts increased. When considering the location and purpose of Internet use, the percentage of Internet addicts was highest in adolescents typically surfing in Internet cafes (18.1%) and playing Internet games (22.5%). PMID:23971432

  16. Socioeconomic Determinants of Bullying in the Workplace: A National Representative Sample in Japan

    Science.gov (United States)

    Tsutsumi, Akizumi; Shimazu, Akihito; Inoue, Akiomi; Odagiri, Yuko; Yoshikawa, Toru; Haratani, Takashi; Shimomitsu, Teruichi

    2015-01-01

    Bullying in the workplace is an increasingly recognized threat to employee health. We sought to test three hypotheses related to the determinants of workplace bullying: power distance at work; safety climate; and frustration related to perceived social inequality. A questionnaire survey was administered to a nationally representative community-based sample of 5,000 residents in Japan aged 20–60 years. The questionnaire included questions about employment, occupation, company size, education, household income, and subjective social status (SSS). We inquired about both the witnessing and personal experience of workplace bullying during the past 30 days. Among 2,384 respondents, data were analyzed from 1,546 workers. Multiple logistic regression analyses were used to examine the social determinants of workplace bullying. Six percent and 15 percent of the total sample reported experiencing or witnessing workplace bullying, respectively. After adjusting for gender and age, temporary employees (Odds Ratio [OR]: 2.45 [95% Confidence Interval (CI) = 1.03–5.85]), junior high school graduates (OR: 2.62 [95%CI: 1.01–6.79]), workers with lowest household income (OR: 4.13 [95%CI:1.58–10.8]), and workers in the lowest SSS stratum (OR: 4.21 [95%CI:1.66–10.7]) were at increased risk of experiencing workplace bullying. When all variables were entered simultaneously in the model, a significant inverse association was observed between higher SSS and experiencing bullying (p = 0.002). Similarly in terms of witnessing bullying; SSS was significantly inversely associated (p = 0.017) while temporary employees reported a significantly higher risk of witnessing bullying compared to permanent workers (OR: 2.25 [95%CI:1.04 to 4.87]). The significant association between SSS and experiencing/witnessing workplace bullying supports the frustration hypothesis. The power distance hypothesis was also partly supported by the finding that temporary employees experienced a higher prevalence

  17. Marijuana withdrawal and aggression among a representative sample of U.S. marijuana users

    Science.gov (United States)

    Smith, Philip H.; Homish, Gregory G.; Leonard, Kenneth E.; Collins, R. Lorraine

    2013-01-01

    Background Previous laboratory-based research suggests that withdrawal from marijuana may cause increased aggression. It is unclear whether this finding extends beyond the laboratory setting to the general population of marijuana users. The purpose of this study was to test a cross-sectional association between marijuana withdrawal symptoms and aggression among a representative sample of U.S. adult marijuana users, and to test whether this association was moderated by previous history of aggression. Methods Data were analyzed from the National Epidemiologic Survey on Alcohol and Related Conditions. Wave Two data (2004–2005) were used for all variables except for history of aggression, which was assessed during the Wave One interview (2001–2002). Two outcomes were examined: self-report general aggression and relationship aggression. Odds ratios for aggression based on withdrawal symptoms and the interaction between withdrawal symptoms and history of aggression were calculated using logistic regression, adjusting for covariates and accounting for the complex survey design. Results Among marijuana users with a history of aggression, marijuana withdrawal was associated with approximately 60% higher odds of past year relationship aggression (p aggression among those without a history of aggression, and no association with general aggression regardless of history of aggression. Conclusions The findings from this study support the notion that laboratory-based increases in aggression due to marijuana withdrawal extend to the general population of marijuana users who have a previous history of aggression. PMID:23380439

  18. Sexual Violence Experienced in the Sport Context by a Representative Sample of Quebec Adolescents

    Science.gov (United States)

    Parent, Sylvie; Lavoie, Francine; Thibodeau, Marie-Ève; Hébert, Martine; Blais, Martin

    2016-01-01

    This is the first study to report the prevalence of sexual violence perpetrated by a sport coach within a representative sample of the general population of adolescents aged between 14 and 17 years (N = 6 450). The questionnaire administered in high schools includes self-reported measures on a variety of dimensions relevant to the study of victimization, including sexual abuse, sexual contacts perceived as consensual, sexual harassment and involvement in an organized sport context. Descriptive and chi-square analyses were performed. The results show that 0.5% of adolescents experienced sexual abuse involving a coach. When considering all adolescents who experienced sexual abuse in their lifetime (10.2%), it appears that 5.3% of them were victims of sexual abuse by a coach. Participants also reported experiencing sexual harassment from a coach (0.4%) and consensual sexual contacts (1.2%) with a coach in the 12 months preceeding the study. Questions are raised on the overrepresentation of boys in situations of sexual victimization experiences in an organized sport context. PMID:25873593

  19. Predictors of utilisation of dental care services in a nationally representative sample of adults.

    Science.gov (United States)

    Guiney, H; Woods, N; Whelton, H; Morgan, K

    2011-12-01

    The objective of this study was to identify the predictors of utilisation of dental care services in Ireland. The 2007 Irish Survey of Lifestyle, Attitudes and Nutrition is a cross-sectional study, conducted in 2006/2007 (n = 10,364), by interviews at home to a representative sample of adults aged 18 years or over. Multivariate logistic regression was used to investigate the influence of socioeconomic, predisposing and enabling factors on the odds of males and females having a dental visit in the past year. The significant predictors of visiting the dentist in the past year were for males: having 3rd level education, employment status, earning 50,000 euros or more, location of residence, use of a car, brushing frequently, and dentition status. For females, the predictors were being between 25-34 or 55-64 years-old, education level, earning 50,000 euros or more, location of residence, use of a car, brushing frequently and dentition status. Predictors of the use of dental services vary by gender. Predictors common to both genders were education level, higher income, location of residence, use of a car, brushing frequently and dentition status. Many of the predictors of dental visiting in the past year are also related to social inequalities in health. These predictors may be useful markers of impact for policies designed to address inequalities in access to oral health services.

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

    Directory of Open Access Journals (Sweden)

    Xiaomeng Zhang

    2006-01-01

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

  1. Is parenting style a predictor of suicide attempts in a representative sample of adolescents?

    Science.gov (United States)

    Donath, Carolin; Graessel, Elmar; Baier, Dirk; Bleich, Stefan; Hillemacher, Thomas

    2014-04-26

    Suicidal ideation and suicide attempts are serious but not rare conditions in adolescents. However, there are several research and practical suicide-prevention initiatives that discuss the possibility of preventing serious self-harm. Profound knowledge about risk and protective factors is therefore necessary. The aim of this study is a) to clarify the role of parenting behavior and parenting styles in adolescents' suicide attempts and b) to identify other statistically significant and clinically relevant risk and protective factors for suicide attempts in a representative sample of German adolescents. In the years 2007/2008, a representative written survey of N = 44,610 students in the 9th grade of different school types in Germany was conducted. In this survey, the lifetime prevalence of suicide attempts was investigated as well as potential predictors including parenting behavior. A three-step statistical analysis was carried out: I) As basic model, the association between parenting and suicide attempts was explored via binary logistic regression controlled for age and sex. II) The predictive values of 13 additional potential risk/protective factors were analyzed with single binary logistic regression analyses for each predictor alone. Non-significant predictors were excluded in Step III. III) In a multivariate binary logistic regression analysis, all significant predictor variables from Step II and the parenting styles were included after testing for multicollinearity. Three parental variables showed a relevant association with suicide attempts in adolescents - (all protective): mother's warmth and father's warmth in childhood and mother's control in adolescence (Step I). In the full model (Step III), Authoritative parenting (protective: OR: .79) and Rejecting-Neglecting parenting (risk: OR: 1.63) were identified as significant predictors (p parental separation events. Parenting style does matter. While children of Authoritative parents profit, children of

  2. Is parenting style a predictor of suicide attempts in a representative sample of adolescents?

    Science.gov (United States)

    2014-01-01

    Background Suicidal ideation and suicide attempts are serious but not rare conditions in adolescents. However, there are several research and practical suicide-prevention initiatives that discuss the possibility of preventing serious self-harm. Profound knowledge about risk and protective factors is therefore necessary. The aim of this study is a) to clarify the role of parenting behavior and parenting styles in adolescents’ suicide attempts and b) to identify other statistically significant and clinically relevant risk and protective factors for suicide attempts in a representative sample of German adolescents. Methods In the years 2007/2008, a representative written survey of N = 44,610 students in the 9th grade of different school types in Germany was conducted. In this survey, the lifetime prevalence of suicide attempts was investigated as well as potential predictors including parenting behavior. A three-step statistical analysis was carried out: I) As basic model, the association between parenting and suicide attempts was explored via binary logistic regression controlled for age and sex. II) The predictive values of 13 additional potential risk/protective factors were analyzed with single binary logistic regression analyses for each predictor alone. Non-significant predictors were excluded in Step III. III) In a multivariate binary logistic regression analysis, all significant predictor variables from Step II and the parenting styles were included after testing for multicollinearity. Results Three parental variables showed a relevant association with suicide attempts in adolescents – (all protective): mother’s warmth and father’s warmth in childhood and mother’s control in adolescence (Step I). In the full model (Step III), Authoritative parenting (protective: OR: .79) and Rejecting-Neglecting parenting (risk: OR: 1.63) were identified as significant predictors (p < .001) for suicidal attempts. Seven further variables were interpreted to be

  3. Under-five mortality among mothers employed in agriculture: findings from a nationally representative sample

    Directory of Open Access Journals (Sweden)

    Rajvir Singh

    2015-01-01

    Full Text Available Background. India accounts for 24% to all under-five mortality in the world. Residence in rural area, poverty and low levels of mother’s education are known confounders of under-five mortality. Since two-thirds of India’s population lives in rural areas, mothers employed in agriculture present a particularly vulnerable population in the Indian context and it is imperative that concerns of this sizeable population are addressed in order to achieve MDG4 targets of reducing U5MR to fewer than 41 per 1,000 by 2015. This study was conducted to examine factors associated with under-five mortality among mothers employed in agriculture.Methods. Data was retrieved from National Family Household Survey-3 in India (2008. The study population is comprised of a national representative sample of single children aged 0 to 59 months and born to mothers aged 15 to 49 years employed in agriculture from all 29 states of India. Univariate and Multivariate Cox PH regression analysis was used to analyse the Hazard Rates of mortality. The predictive power of child mortality among mothers employed in agriculture was assessed by calculating the area under the receiver operating characteristic (ROC curve.Results. An increase in mothers’ ages corresponds with a decrease in child mortality. Breastfeeding reduces child mortality by 70% (HR 0.30, 0.25–0.35, p = 0.001. Standard of Living reduces child mortality by 32% with high standard of living (HR 0.68, 0.52–0.89, 0.001 in comparison to low standard of living. Prenatal care (HR 0.40, 0.34–0.48, p = 0.001 and breastfeeding health nutrition education (HR 0.45, 0.31–0.66, p = 0.001 are associated significant factors for child mortality. Birth Order five is a risk factor for mortality (HR 1.49, 1.05–2.10, p = 0.04 in comparison to Birth Order one among women engaged in agriculture while the household size (6–10 members and ≥ 11 members is significant in reducing child mortality in comparison to ≤5 members

  4. Gambling and violence in a nationally representative sample of UK men.

    Science.gov (United States)

    Roberts, Amanda; Coid, Jeremy; King, Robert; Murphy, Raegan; Turner, John; Bowden-Jones, Henrietta; Du Preez, Katie Palmer; Landon, Jason

    2016-12-01

    The relationship between violence and problem gambling in general population samples is under-researched and requires further attention to inform treatment and prevention efforts. We investigated the relationship between gambling problems and violence among men and sought to determine if the link can be accounted for by mental disorders, alcohol and drug dependence and impulsivity. A cross-sectional survey. A UK representative general population survey conducted in 2009. A total of 3025 UK men aged 18-64 years. Binary logistic regression was used to examine relationships. Outcome measures included gambling behaviour and self-reports of violence. Covariates included alcohol and drug dependence, mental illness, impulsivity and socio-demography. Problem gambling and probable pathological gambling were associated with increased odds of the perpetration of violence [adjusted odd ratios (AOR) = 3.09, confidence interval (CI) = 1.90-5.00 and 4.09, CI = 2.76-6.30, respectively] and a range of other behaviours, such as using a weapon (AORs = 4.93, CI = 2.52-9.63 and 6.33, CI = 3.52-11.38) and the perpetration of intimate partner violence (AOR = 9.80, CI =2.45-39.04). The results were attenuated when adjusted for comorbid mental illness and impulsivity, but remained statistically significant. Alcohol and drug dependence had the most impact; relationships were most attenuated when they added into the models, with the latter having the largest effect. Among men in the United Kingdom, self-reports of problem/pathological gambling remain predictive of a range of measures of violent behaviour after adjusting for alcohol and drug dependence, comorbid mental disorder and impulsivity; of the covariates, alcohol and drug dependence have the greatest effect in attenuating the gambling-violence association. © 2016 Society for the Study of Addiction.

  5. Personality and attitudinal correlates of meat consumption: Results of two representative German samples.

    Science.gov (United States)

    Pfeiler, Tamara M; Egloff, Boris

    2018-02-01

    The vast amount of meat consumed in the Western world is critically discussed with regard to negative health consequences, environmental impact, and ethical concerns for animals, emphasizing the need to extend knowledge regarding the correlates of meat consumption in the general population. In the present article, we conducted two studies examining the associations between meat consumption and personality traits, political attitudes, and environmental attitudes in two large German representative samples (N total  = 8,879, aged 18-96 years). Cross-sectional data on frequency of meat consumption, socio-demographics, personality traits, and political and environmental attitudes were collected via self-reports. In both studies, male sex, younger age, and lower educational attainment were significantly positively related to meat consumption. In Study 1, results of the partial correlations and the hierarchical regression analysis controlling for socio-demographics showed that the personality traits of openness and agreeableness, as well as conservative political and social views, explained unique variance in meat consumption. In Study 2, partial correlations and hierarchical regression analyses showed that openness, agreeableness, and conscientiousness were all uniquely negatively related to meat consumption. Moreover, these analyses documented that people scoring high in right-wing attitudes and low in pro-environmental attitudes reported more overall meat consumption. Taken together, these two studies provided evidence that socio-demographics, personality traits, and attitudes are indeed related to how much meat is consumed. Implications and future prospects for the study of individual differences in meat consumption are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The influence of stress, depression, and anxiety on PSA screening rates in a nationally representative sample.

    Science.gov (United States)

    Kotwal, Ashwin A; Schumm, Phil; Mohile, Supriya G; Dale, William

    2012-12-01

    Prostate-specific antigen (PSA) testing for prostate cancer is controversial, with concerning rates of both overscreening and underscreening. The reasons for the observed rates of screening are unknown, and few studies have examined the relationship of psychological health to PSA screening rates. Understanding this relationship can help guide interventions to improve informed decision-making for screening. A nationally representative sample of men 57-85 years old without prostate cancer (N = 1169) from the National Social life, Health and Aging Project was analyzed. The independent relationship of validated psychological health scales measuring stress, anxiety, and depression to PSA testing rates was assessed using multivariable logistic regression analyses. PSA screening rates were significantly lower for men with higher perceived stress [odds ratio (OR) = 0.76, P = 0.006], but not for higher depressive symptoms (OR = 0.89, P = 0.22) when accounting for stress. Anxiety influences PSA screening through an interaction with number of doctor visits (P = 0.02). Among the men who visited the doctor once those with higher anxiety were less likely to be screened (OR = 0.65, P = 0.04). Conversely, those who visited the doctor 10+ times with higher anxiety were more likely to be screened (OR = 1.71, P = 0.04). Perceived stress significantly lowers PSA screening likelihood, and it seems to partly mediate the negative relationship of depression with screening likelihood. Anxiety affects PSA screening rates differently for men with different numbers of doctor visits. Interventions to influence PSA screening rates should recognize the role of the patients' psychological state to improve their likelihood of making informed decisions and improve screening appropriateness.

  7. Parenting style and mental disorders in a nationally representative sample of US adolescents.

    Science.gov (United States)

    Eun, John David; Paksarian, Diana; He, Jian-Ping; Merikangas, Kathleen Ries

    2018-01-01

    We examined associations between parenting style and past-year mental disorders in a nationally representative cross-sectional survey of US adolescents and whether the associations differed by adolescent demographic characteristics. The sample included 6483 adolescents aged 13-18 years who were interviewed for a full range of DSM-IV mental disorders. Parenting style was assessed by adolescent-reported maternal and paternal care and control using items from the Parental Bonding Instrument. We controlled for socio-demographics, parental history of mental disorders, stressful life events, sexual violence, inter-parental conflict, and household composition. We also tested for two-way interactions between parental care and control and adolescent age, sex, and race/ethnicity. In adjusted models, high maternal care was associated with lower odds of depressive, eating, and behavioral disorders, and high maternal control was associated with greater odds of depressive, anxiety, eating, and behavioral disorders. High paternal care was associated with lower odds of social phobia and alcohol abuse/dependence. High paternal control was associated with greater odds of agoraphobia and alcohol abuse/dependence but with lower odds of attention-deficit/hyperactivity disorder. Associations of maternal and paternal control with anxiety disorders and substance abuse/dependence differed by sex. High paternal care was associated with lower odds of anxiety disorders only among Hispanics and non-Hispanic blacks. Perceived parental care and control were associated with adolescent mental disorders after controlling for multiple potential confounders. Differential patterns of association were found according to adolescent sex and race/ethnicity. Findings have implications for prevention and intervention programs that incorporate familial contextual factors.

  8. Dietary predictors of childhood obesity in a representative sample of children in north east of Iran.

    Science.gov (United States)

    Baygi, Fereshteh; Qorbani, Mostafa; Dorosty, Ahmad Reza; Kelishadi, Roya; Asayesh, Hamid; Rezapour, Aziz; Mohammadi, Younes; Mohammadi, Fatemeh

    2013-07-01

    The prevalence of obesity is increasing in Iranian youngsters. This study aimed to assess some dietary determinants of obesity in a representative sample of children in Neishabour, a city in northeastern, Iran. This case-control study was conducted among 114 school students, aged 6-12 years, with a body mass index (BMI) ≥95th (based on percentile of Iranian children) as the case group and 102 age- and gender-matched controls, who were selected from their non-obese classmates. Nutrient intake data were collected by trained nutritionists by using two 24-hour-dietary recalls through maternal interviews in the presence of their child. A food frequency questionnaire was used for detecting the snack consumption patterns. Statistical analysis was done using univariate and multivariate logistic regression (MLR) by SPSS version 16. In univariate logistic regression, total energy, protein, carbohydrate, fat (including saturated, mono- and poly-unsaturated fat), and dietary fiber were the positive predictors of obesity in studied children. The estimated crude ORs for frequency of corn-based extruded snacks, carbonated beverages, potato chips, fast foods, and chocolate consumption were statistically significant. After MLR analysis, the association of obesity remained significant with energy intake (OR = 2.489, 95%CI: 1.667-3.716), frequency of corn-based extruded snacks (OR = 1.122, 95%CI: 1.007-1.250), and potato chips (OR = 1.143, 95%CI:1.024-1.276). The MLR analysis showed that dietary fiber (OR = 0.601, 95%CI: 0.368-0.983) and natural fruit juice intake (OR = 0.909, 95%CI: 0.835-0.988) were protective factors against obesity. The findings serve to confirm the role of an unhealthy diet, notably calorie-dense snacks, in childhood obesity. Healthy dietary habits, such as the consumption of high-fiber foods, should be encouraged among children.

  9. Association of occupation, employment contract, and company size with mental health in a national representative sample of employees in Japan.

    Science.gov (United States)

    Inoue, Akiomi; Kawakami, Norito; Tsuchiya, Masao; Sakurai, Keiko; Hashimoto, Hideki

    2010-01-01

    The purpose of this study was to investigate the cross-sectional association of employment contract, company size, and occupation with psychological distress using a nationally representative sample of the Japanese population. From June through July 2007, a total of 9,461 male and 7,717 female employees living in the community were randomly selected and surveyed using a self-administered questionnaire and interview including questions about occupational class variables, psychological distress (K6 scale), treatment for mental disorders, and other covariates. Among males, part-time workers had a significantly higher prevalence of psychological distress than permanent workers. Among females, temporary/contract workers had a significantly higher prevalence of psychological distress than permanent workers. Among males, those who worked at companies with 300-999 employees had a significantly higher prevalence of psychological distress than those who worked at the smallest companies (with 1-29 employees). Company size was not significantly associated with psychological distress among females. Additionally, occupation was not significantly associated with psychological distress among males or females. Similar patterns were observed when the analyses were conducted for those who had psychological distress and/or received treatment for mental disorders. Working as part-time workers, for males, and as temporary/contract workers, for females, may be associated with poor mental health in Japan. No clear gradient in mental health along company size or occupation was observed in Japan.

  10. Comparison of teen and adult driver crash scenarios in a nationally representative sample of serious crashes.

    Science.gov (United States)

    McDonald, Catherine C; Curry, Allison E; Kandadai, Venk; Sommers, Marilyn S; Winston, Flaura K

    2014-11-01

    Motor vehicle crashes are the leading cause of death and acquired disability during the first four decades of life. While teen drivers have the highest crash risk, few studies examine the similarities and differences in teen and adult driver crashes. We aimed to: (1) identify and compare the most frequent crash scenarios-integrated information on a vehicle's movement prior to crash, immediate pre-crash event, and crash configuration-for teen and adult drivers involved in serious crashes, and (2) for the most frequent scenarios, explore whether the distribution of driver critical errors differed for teens and adult drivers. We analyzed data from the National Motor Vehicle Crash Causation Survey, a nationally representative study of serious crashes conducted by the U.S. National Highway Traffic Safety Administration from 2005 to 2007. Our sample included 642 16- to 19-year-old and 1167 35- to 54-year-old crash-involved drivers (weighted n=296,482 and 439,356, respectively) who made a critical error that led to their crash's critical pre-crash event (i.e., event that made the crash inevitable). We estimated prevalence ratios (PR) and 95% confidence intervals (CI) to compare the relative frequency of crash scenarios and driver critical errors. The top five crash scenarios among teen drivers, accounting for 37.3% of their crashes, included: (1) going straight, other vehicle stopped, rear end; (2) stopped in traffic lane, turning left at intersection, turn into path of other vehicle; (3) negotiating curve, off right edge of road, right roadside departure; (4) going straight, off right edge of road, right roadside departure; and (5) stopped in lane, turning left at intersection, turn across path of other vehicle. The top five crash scenarios among adult drivers, accounting for 33.9% of their crashes, included the same scenarios as the teen drivers with the exception of scenario (3) and the addition of going straight, crossing over an intersection, and continuing on a

  11. Representing major soil variability at regional scale by constrained Latin Hypercube Sampling of remote sensing data

    NARCIS (Netherlands)

    Mulder, V.L.; Bruin, de S.; Schaepman, M.E.

    2013-01-01

    This paper presents a sparse, remote sensing-based sampling approach making use of conditioned Latin Hypercube Sampling (cLHS) to assess variability in soil properties at regional scale. The method optimizes the sampling scheme for a defined spatial population based on selected covariates, which are

  12. Health Correlates of Insomnia Symptoms and Comorbid Mental Disorders in a Nationally Representative Sample of US Adolescents

    NARCIS (Netherlands)

    Blank, M.; Zhang, J.H.; Lamers, F.; Taylor, A.D.; Hickie, I.B.; Merikangas, K.R.

    2015-01-01

    Study Objectives: To estimate the prevalence and health correlates of insomnia symptoms and their association with comorbid mental disorders in a nationally representative sample of adolescents in the United States. Design: National representative cross-sectional study. Setting: Population-based

  13. Association of Dietary Behaviors with Physical Activity in a Nationally Representative Sample of Children and Adolescents: the CASPIAN- IV Study

    Directory of Open Access Journals (Sweden)

    Saeid Safiri

    2016-03-01

    Full Text Available Background: Nutritional health and adequate physical activity (PA, especially in childhood and grow periods, have a substantial role in health. This study assessed the association of dietary behaviors (main courses and snacks intake with PA in children and adolescents. Materials and Methods: Using multistage random cluster sampling method, a representative sample of 14,880 school students were selected from urban and rural areas of 30 provinces of Iran. Through a validated questionnaire, daily consumption of main course ( breakfast, lunch, and dinner as well as daily consumption of different snacks and health foods ( fast foods, milk, vegetables, dry fruits, fresh fruits, sweetened beverages, salty snacks and sweets were recorded for every participants. Information of past week weekly frequency of leisure time PA was collected. Results: Overall, 13,486 out of 14,880 students (response rate: 90.6% participated in this survey. Participants consisted of 6,640 (49.2% girls and 75.6% urban residents; their mean and standard deviation (SD age was 12.47 (3.36 years. Daily consumption of fresh fruits (odds ratio [OR]: 1.35, 95%confidence interval [CI]: 1.20-1.52, dried fruits (OR: 1.21; 95%CI: 1.06-1.40, vegetable (OR: 1.39; 95% CI: 1.24-1.56, and milk (OR: 1.35; 95% CI: 1.21-1.52 increased the odds of high PA compare to low PA in adjusted model.  Skipping the breakfast, lunch and dinner decreased the odds of moderate and high PA compare to low PA (P

  14. Buffer AVL Alone Does Not Inactivate Ebola Virus in a Representative Clinical Sample Type.

    Science.gov (United States)

    Smither, Sophie J; Weller, Simon A; Phelps, Amanda; Eastaugh, Lin; Ngugi, Sarah; O'Brien, Lyn M; Steward, Jackie; Lonsdale, Steve G; Lever, Mark S

    2015-10-01

    Rapid inactivation of Ebola virus (EBOV) is crucial for high-throughput testing of clinical samples in low-resource, outbreak scenarios. The EBOV inactivation efficacy of Buffer AVL (Qiagen) was tested against marmoset serum (EBOV concentration of 1 × 10(8) 50% tissue culture infective dose per milliliter [TCID50 · ml(-1)]) and murine blood (EBOV concentration of 1 × 10(7) TCID50 · ml(-1)) at 4:1 vol/vol buffer/sample ratios. Posttreatment cell culture and enzyme-linked immunosorbent assay (ELISA) analysis indicated that treatment with Buffer AVL did not inactivate EBOV in 67% of samples, indicating that Buffer AVL, which is designed for RNA extraction and not virus inactivation, cannot be guaranteed to inactivate EBOV in diagnostic samples. Murine blood samples treated with ethanol (4:1 [vol/vol] ethanol/sample) or heat (60°C for 15 min) also showed no viral inactivation in 67% or 100% of samples, respectively. However, combined Buffer AVL and ethanol or Buffer AVL and heat treatments showed total viral inactivation in 100% of samples tested. The Buffer AVL plus ethanol and Buffer AVL plus heat treatments were also shown not to affect the extraction of PCR quality RNA from EBOV-spiked murine blood samples. © Crown copyright 2015.

  15. Representative sampling of animal feed and mixtures in the Danish agricultural sector

    DEFF Research Database (Denmark)

    Petersen, Lars; Esbensen, Kim Harry

    2005-01-01

    Sampling of grain, animal feeds (solid & liquid) including important mineral mixtures in the Danish agricultural sector is subject to an ongoing investigation with the objective of improving existing (sub-optimal) sampling procedures. Results from the first 6 months are presented here; the projec...

  16. Diagnostic Accuracy of the Posttraumatic Stress Disorder Checklist–Civilian Version in a Representative Military Sample

    DEFF Research Database (Denmark)

    Karstoft, Karen-Inge; Andersen, Søren B.; Bertelsen, Mette

    2014-01-01

    This study aimed to assess the diagnostic accuracy of the Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C; Weathers, Litz, Herman, Huska, & Keane, 1993) and to establish the most accurate cutoff for prevalence estimation of posttraumatic stress disorder (PTSD) in a representative...

  17. A comparison of methods for representing random taste heterogeneity in discrete choice models

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Hess, Stephane

    2009-01-01

    This paper reports the findings of a systematic study using Monte Carlo experiments and a real dataset aimed at comparing the performance of various ways of specifying random taste heterogeneity in a discrete choice model. Specifically, the analysis compares the performance of two recent advanced...... distributions. Both approaches allow the researcher to increase the number of parameters as desired. The paper provides a range of evidence on the ability of the various approaches to recover various distributions from data. The two advanced approaches are comparable in terms of the likelihoods achieved...

  18. A comprehensive literature review reflecting fifteen years of debate regarding the representativity of reverse circulation vs blast hole drill sampling

    DEFF Research Database (Denmark)

    Engström, Karin

    2017-01-01

    Blast hole sampling is widely used for grade control by the mining industry all over the world, both in precious and base metal open pit mining. Blast hole (BH) samples are often regarded as inferior in comparison to “proper drill sampling” like reverse circulation (RC) and diamond (core) drilling...... (DD), and are accused of lacking representativity by the sampling community. The present paper aims at collecting all peer reviewed publications from 2000 onwards that concern open pit mine sampling performance of BH, RC and/or DD drill sampling. This will form a comprehensive literature review...

  19. REPRESENTATIVE OF LGBTT IN PRINTED LOCAL PRESS GAZIANTEP SAMPLE (2009-2014

    Directory of Open Access Journals (Sweden)

    Fatma Yeşil

    2017-07-01

    Full Text Available The basic aim of the paper is an attempt to find out how Van Dijk's critical discourse analysis of LGBTT (Lesbian, Gay, Bisexual, Transvestite, Transsexual individuals who are represented at the local press. Sabah, Hâkimiyet, Express, Gaziantep27, Olay and Telgraf newspapers were selected from Gaziantep Printed Local Press for the study and how these LGBTT people were represented in these newspapers. The articles reviewed for the study were published between 2009 and 2014 is a key criterion for LGBTT people to be involved directly or indirectly (with links to various topics under different headings. In the context of Van Dijk's critical discourse analysis based on the study, and in the light of the determined criteria, the existing news obtained were carefully scanned from newspapers, examined and analyzed in detail by the method of critical discourse analysis.

  20. Determination of hardiness by psychosocial and behavioural variables in a representative Czech population sample

    Czech Academy of Sciences Publication Activity Database

    Kebza, V.; Šolcová, Iva

    2008-01-01

    Roč. 23, Suppl. 1 (2008), s. 158 ISSN 0887-0446 R&D Projects: GA AV ČR(CZ) IAA 700250701 Institutional research plan: CEZ:AV0Z70250504 Keywords : hardiness * Czech population sample * social support Subject RIV: AN - Psychology

  1. Dietary patterns and depressive mood in a multiethnic representative sample of Texas eighth graders

    Science.gov (United States)

    The purpose of the study was to examine the relation between dietary patterns and depressive mood among 8th grade students in Texas. Data were from the 2004–2005 School Physical Activity and Nutrition study, a multistage probability-based sample of Texas 8th graders. Participants (n=8827; 14.7% Afri...

  2. 21 CFR 111.80 - What representative samples must you collect?

    Science.gov (United States)

    2010-04-01

    ..., PACKAGING, LABELING, OR HOLDING OPERATIONS FOR DIETARY SUPPLEMENTS Requirement to Establish a Production and... manufactured batch at points, steps, or stages, in the manufacturing process as specified in the master... statistical sampling plan (or otherwise every finished batch), before releasing for distribution to verify...

  3. 77 FR 72205 - Testing and Labeling Pertaining to Product Certification Regarding Representative Samples for...

    Science.gov (United States)

    2012-12-05

    ... testing periodically and when there has been a material change in the product's design or manufacturing... control data during product manufacture; and using manufacturing techniques with intrinsic manufacturing... sample in the production population an equal probability of being selected (75 FR at 28349 through 28350...

  4. Associations between Delinquency and Suicidal Behaviors in a Nationally Representative Sample of Adolescents

    Science.gov (United States)

    Thompson, Martie P.; Kingree, J. B.; Ho, Ching-hua

    2006-01-01

    Suicide was the second leading cause of death for 14-17 years olds in 2002. Prior studies indicate that suicidal behaviors are especially common among juvenile delinquents, yet this association has not been examined in a national sample. The 2003 Youth Risk Behavior Surveillance System was used to examine associations between suicidal behaviors…

  5. [Rosenberg self-esteem scale: validation in a representative sample of Chilean adults].

    Science.gov (United States)

    Rojas-Barahona, Cristian A; Zegers, Beatriz; Förster, Carla E

    2009-06-01

    Self-esteem is positively associated to the well being of people and could be a good mental health indicator. To determine the reliability and validity of the Rosenberg Self-esteem Scale in a Chilean adult sample. The instrument was applied to 473 subjects living in the Metropolitan Region of Santiago, evenly distributed according to gender, age, educational level and income. The Neugarten Life Satisfaction index (LSI-A) was also applied to the sample. Cronbach's alpha for reliability of the scale was 0.754. There was no gender bias and factor analysis grouped items into two factors (5 positive and 5 negative). The instrument had a correlation of 0.455 with the LSI-A. The Rosenberg Self-esteem Scale meets the criteria for validity and reliability of a quality instrument to measure self-esteem in Chile.

  6. Personality correlates of type 1 diabetes in a national representative sample

    OpenAIRE

    Čukić, Iva; Weiss, Alexander

    2016-01-01

    We examined cross-sectional relationships between personality traits and type 1 diabetes. The sample (N=8490) was taken from the 1982-84 wave of the National Health and Nutrition Examination Survey Epidemiological Follow-up Study. We fit three logistic regression models to test whether neuroticism, extraversion, openness, or the Type A behavior pattern were associated with type 1 diabetes. Model 1 included sex, age, race/ethnicity and all four personality traits. Model 2 added depressive symp...

  7. γ-Ray spectrometry of radon in water and the role of radon to representatively sample aquifers

    International Nuclear Information System (INIS)

    Talha, S.A.; Lindsay, R.; Newman, R.T.; Meijer, R.J. de; Maleka, P.P.; Hlatshwayo, I.N.; Mlwilo, N.A.; Mohanty, A.K.

    2008-01-01

    Measurement of radon in water by γ-ray spectrometry using a HPGe detector has been investigated to determine aquifer characteristics. The radon activity concentration is determined by taking the weighted average of the concentrations derived from γ-ray lines associated with 214 Pb and 214 Bi decay. The role of accurate radon data to representatively sample aquifers was also investigated by studying a semi-cased borehole. A simplified physical model describing the change of radon concentration with the pumping time, reproduces the data and predicts the time for representative sampling of the aquifer

  8. Association of a television in the bedroom with increased adiposity gain in a nationally representative sample of children and adolescents.

    Science.gov (United States)

    Gilbert-Diamond, Diane; Li, Zhigang; Adachi-Mejia, Anna M; McClure, Auden C; Sargent, James D

    2014-05-01

    Obesity affects health in children and adolescents. Television viewing is an established risk factor for obesity in youth. No prospective study has assessed whether a bedroom television confers an additional risk for obesity in youth. To assess the prospective association between the presence of a bedroom television and change in body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), independent of television viewing, in a nationally representative sample of US children and adolescents. We conducted a random-digit prospective telephone survey that captured children and adolescents from across the United States. Participants included 6522 boys and girls aged 10 to 14 years at baseline who were surveyed via telephone about media risk factors for obesity.Weighted regressions assessed adiposity at 2- and 4-year follow-up, controlling for television and movie viewing, video-game playing, parenting, age, sex, race or ethnicity, household income, and parental educational level. Report of having a television in the bedroom at baseline. Age- and sex-adjusted BMI based on self-report and parent report of weight and height at 2- and 4-year follow-up. Distributions for age, sex, race or ethnicity, and socioeconomic status were similar to census estimates for the US population. Sample weighting methods accounted for higher dropout rates among ethnic minorities and those with lower socioeconomic status. Bedroom televisions were reported by 59.1%of participants at baseline, with boys, ethnic minorities, and those of lower socioeconomic status having significantly higher rates. In multivariate analyses, having a bedroom television was associated with an excess BMI of 0.57 (95%CI, 0.31-0.82) and 0.75 (0.38-1.12) at years 2 and 4, respectively, and a BMI gain of 0.24 (0.02-0.45) from years 2 to 4. Having a bedroom television is associated with weight gain beyond the effect of television viewing time. This association could be the result of

  9. Association between anthropometry and high blood pressure in a representative sample of preschoolers in madrid.

    Science.gov (United States)

    Santos-Beneit, Gloria; Sotos-Prieto, Mercedes; Pocock, Stuart; Redondo, Juliana; Fuster, Valentín; Peñalvo, José L

    2015-06-01

    Program SI! is a multi-level, school-based intervention for the promotion of cardiovascular health from early childhood. The aim of this paper is to characterize the prevalence of obesity and high blood pressure in the preschoolers enrolled in the study, and to compare various criteria for classifying obesity. The study was a cluster-randomized controlled intervention trial including 24 state schools in Madrid (Spain). Weight, height, triceps and subscapular skinfold thicknesses, waist circumference, and systolic and diastolic blood pressure were measured in 2011 children (1009 boys and 1002 girls) aged 3 to 5 years (3.7 [0.9]). Body mass index and blood pressure were classified by corresponding task force criteria. Obesity was studied by 6 different criteria. Associations of body mass index, body weight, body fat, and waist circumference on blood pressure were examined, and the risk of high blood pressure in relation to tertiles of body mass index was calculated. The prevalence of obesity according to the International Obesity Task Force varied from 2% at age 3 to 8% at age 5, and the overall prevalence of high blood pressure (≥ 90th percentile) was 20%. Sex- and age-specific criteria for obesity showed better agreement with the reference than a single generalized cutoff. The risk of high blood pressure was higher for the highest tertile of body mass index distribution. The highest prevalence of obesity and high blood pressure was found among older children. The classification of obesity in children was more accurate using sex- and age-specific cutoffs. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  10. External validity of randomized controlled trials of glycaemic control and vascular disease: how representative are participants?

    Science.gov (United States)

    Saunders, C; Byrne, C D; Guthrie, B; Lindsay, R S; McKnight, J A; Philip, S; Sattar, N; Walker, J J; Wild, S H

    2013-03-01

    To describe the proportion of people with Type 2 diabetes living in Scotland who meet eligibility criteria for inclusion in several large randomized controlled trials of glycaemic control to inform physicians and guideline developers about the generalizibility of trial results. A literature review was performed to identify large trials assessing the impact of glycaemic control on risk of macrovascular disease. Inclusion and exclusion criteria from each trial were applied to data on the population of people with a diagnosis of Type 2 diabetes living in Scotland in 2008 (n = 180,590) in a population-based cross-sectional study and the number and proportion of people eligible for each trial was determined. Seven trials were identified. The proportion of people with Type 2 diabetes who met the eligibility criteria for the trials ranged from 3.5 to 50.7%. Trial participants were younger at age of diagnosis of diabetes and at time of trial recruitment than in the Scottish study population. The application of upper age criteria excluded the largest proportion of patients, with up to 39% of people with Type 2 diabetes ineligible for a trial with the most stringent criteria based on age alone. We found that many of the large trials of glycaemic control among people with Type 2 diabetes have limited external validity when applied to a population-based cohort of people with Type 2 diabetes. In particular, the age distribution of trial participants often does not reflect that of people with Type 2 diabetes in a contemporary British population. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

  11. (Why) do victims become perpetrators? Intergenerational transmission of parental violence in a representative German sample.

    Science.gov (United States)

    Hellmann, Deborah F; Stiller, Anja; Glaubitz, Christoffer; Kliem, Sören

    2018-03-01

    Child maltreatment can severely impair children's emotional and physical well-being as well as their individual development across the life span. In 2011, the Criminological Research Institute of Lower Saxony (Germany), conducted a nationally representative victim survey on diverse forms of victimizations (N = 11,428). Among other things, experienced and exerted parental violence as well as participants' knowledge regarding the abolition of the parental right of corporal punishment were assessed. Apart from providing current estimates of the prevalence of experienced and exerted parental violence in Germany, we identified specific risk markers for the intergenerational transmission of parental violence. In summary, 52.6% of the participants reported experiences of at least one incident of at least minor parental violence until the age of 16 years, and 22.9% had exerted at least once at least one act of minor violence against their own children. Nonparametric conditional inference tree analyses revealed experienced parental violence as the most important risk marker for exerting parental violence. Furthermore, the number of children currently cared for, parental age, and origin as well as knowledge about the current legal situation regarding corporal punishment were significantly associated with exerting parental violence. For individuals without a history of parental violence, lack of experienced parental warmth and an age between 33 and 40 years increased the risk of exerting parental violence. The results are discussed in terms of their implications for designing effective prevention and intervention strategies. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  12. ATTACHMENT AS A PREDICTOR OF RISK FOR EATING DISORDERS ON A REPRESENTATIVE HUNGARIAN ADULT SAMPLE.

    Science.gov (United States)

    Szalai, Tamás Dömötör; Czeglédi, Edit

    2015-11-30

    Many studies confirm the relationship between attachment disturbances and (the severity of) eating disorders, however among them only one Hungarian study can be found. The exact predisposing traits of attachment and the strength of relationship is still uncleared. Our aim was to explore these aspects. Study was based on a cross-sectional nationally representative survey, called "Hungarostudy 2013" (N = 2000, 46.9% males, mean age 46.9 years, SD = 18.24 years). Measures: Sociodemographic and self-reported anthropometric data (weight and height), short Hungarian version of Relationship Scale Questionnaire, SCOFF questionnaire and short Hungarian version of Beck Depression Inventory. The frequency of risk for eating disorders (anorexia or bulimia nervosa) was 3.9% (N = 76) among the respondents (N = 1860). Attachment anxiety was significantly higher in the risk for eating disorders group (t (1888) = -3.939, p eating disorders after adjusting for the potential background variables (OR = 1.09, p = 0.040). Detachment was not a significant predictor of risk for eating disorders (OR = 0.98, p = 0.515). Younger age (OR = 0.97, p cross-sectional predictors of risk for eating disorders. The explained variance of the model was 10.7%. The study supported, that higher attachment anxiety is associated with the increased risk of eating disorders, with a possible therapeutic relevance. Assessment of attachment's further aspects and creating multivariable models are required for more thorough understanding and optimising of intervention points.

  13. Mental health literacy of depression: gender differences and attitudinal antecedents in a representative British sample.

    Directory of Open Access Journals (Sweden)

    Viren Swami

    Full Text Available Poor mental health literacy and negative attitudes toward individuals with mental health disorders may impede optimal help-seeking for symptoms of mental ill-health. The present study examined the ability to recognize cases of depression as a function of respondent and target gender, as well as individual psychological differences in attitudes toward persons with depression.In a representative British general population survey, the ability to correctly recognize vignettes of depression was assessed among 1,218 adults. Respondents also rated the vignettes along a number of attitudinal dimensions and completed measures of attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes.There were significant differences in the ability to correctly identify cases of depression as a function of respondent and target gender. Respondents were more likely to indicate that a male vignette did not suffer from a mental health disorder compared to a female vignette, and women were more likely than men to indicate that the male vignette suffered from a mental health disorder. Attitudes toward persons with depression were associated with attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes.Initiatives that consider the impact of gender stereotypes as well as individual differences may enhance mental health literacy, which in turn is associated with improved help-seeking behaviors for symptoms of mental ill-health.

  14. Association among smoking, depression, and anxiety: findings from a representative sample of Korean adolescents

    Directory of Open Access Journals (Sweden)

    Haewon Byeon

    2015-10-01

    Full Text Available This study investigated the relationship between smoking and depression and anxiety using data from a nationwide survey representing Korean adolescents. Subjects were 6,489 adolescents in middle and high school (age 13–18 who had participated in the 2011 Korean Study of Promotion Policies on Children and Adolescents—Mental Health (KSPCAM. Daily smoking number of times for current smokers was classified as 1–2 times, 2–4 times and over 5 times. The odds ratio for the statistical test was presented using hierarchical logistic regression. When adjusted for covariates (gender, age, household economy, type of residing city, type of school, school record, satisfaction with school life, subjective health status, satisfaction with relationship with parents, and drinking experience, smokers more significantly likely to have depression (OR = 1.27, 95% CI [1.02–1.57], and anxiety (OR = 1.49, 95% CI [1.14–1.96] than non-smokers (p < 0.05. In addition, adolescents who smoke more than 5 cigarettes a day were 1.5 times more likely to have depression (OR = 1.48, 95% CI [1.13–1.92] and anxiety (OR = 1.49, 95% CI [1.07–2.08] than those who do not smoke. Smoking in adolescence was found to be significantly related with depression and anxiety. To promote the mental health of adolescents, effective smoking cessation programs are required.

  15. Sampling Polya-Gamma random variates: alternate and approximate techniques

    OpenAIRE

    Windle, Jesse; Polson, Nicholas G.; Scott, James G.

    2014-01-01

    Efficiently sampling from the P\\'olya-Gamma distribution, ${PG}(b,z)$, is an essential element of P\\'olya-Gamma data augmentation. Polson et. al (2013) show how to efficiently sample from the ${PG}(1,z)$ distribution. We build two new samplers that offer improved performance when sampling from the ${PG}(b,z)$ distribution and $b$ is not unity.

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

    Science.gov (United States)

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

    2016-11-17

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

  17. Change in Corporal Punishment Over Time in a Representative Sample of Canadian Parents.

    Science.gov (United States)

    Fréchette, Sabrina; Romano, Elisa

    2015-08-01

    Corporal punishment is a controversial form of discipline. Although its prevalence appears high, legal reforms and public education efforts to limit corporal punishment may be resulting in a decrease in its prevalence and frequency of use. This study drew on Canadian nationally representative data to understand the social change that might be happening and to characterize parents who continue to use corporal punishment. The study relied on cross-sectional data from Cycles 1 (1994) to 8 (2008) of the Canadian National Longitudinal Survey of Children and Youth to examine parental reports of corporal punishment for children ages 2–11 years. Analyses were conducted separately for 2- to 5-, 6- to 9-, and 10- to 11-year-olds, and sociodemographics associated with corporal punishment were examined. A significant decrease in the prevalence and frequency of corporal punishment use was observed across time for all age groups. Child sex, parent age, employment status, family structure, household size, immigration status, ethnicity, and religion significantly distinguished parents who use corporal punishment from those who do not, but there was variability across the age groups. Effect sizes question the relevance of the observed decrease in corporal punishment from an applied perspective. Approximately 25% of Canadian parents still use corporal punishment with children ages 2–11 years; therefore, it remains an issue that merits continued attention. Certain child, parent, and family characteristics seem to characterize parents who use corporal punishment, but other more dynamic variables may be important to consider, such as parental stress and their attitudes toward corporal punishment.

  18. Gambling and negative life events in a nationally representative sample of UK men.

    Science.gov (United States)

    Roberts, Amanda; Sharman, Stephen; Coid, Jeremy; Murphy, Raegan; Bowden-Jones, Henrietta; Cowlishaw, Sean; Landon, Jason

    2017-12-01

    The links between gambling problems, trauma and life stressors are known to exist but understanding the extent of these relationships will allow for greater efficacy in early intervention and treatment. We investigated these relationships among men and sought to determine whether links were attenuated by alcohol and drug use problems. A cross-sectional UK representative general population survey was conducted in 2009 with 3025 men aged 18-64years. Measurements included self-reported gambling behaviours, as measured by the South Oaks Gambling Scale (SOGS) and traumatic or stressful life events. Covariates included alcohol and drug dependence and socio-demographics. Binary logistic regression models were used to examine associations. Problem gambling (SOGS 3-4) and probable pathological gambling (SOGS 5+) were associated with increased odds of trauma in childhood (e.g. violence in the home (Adjusted Odd Ratios (AOR) 3.0 (CI=1.8-5.0) and 2.6 (CI=1.7-4.1) respectively), and life stressors in adulthood (e.g. intimate partner violence (AORs 4.5 (CI=2.0-10.3) and 4.7 (CI=2.3-9.7) and homelessness (AORs 2.2 (CI=1.1-4.6) and 3.2 (CI=1.9-5.5)). Results were attenuated when adjusted for probable alcohol and drug dependence with the latter having largest effects. Among men in the United Kingdom, disordered gambling remains uniquely associated with trauma and life stressors in childhood and adulthood after adjusting for alcohol and drug dependence. The results support a need for disordered gambling treatment services to undertake routine screening for alcohol, drugs, IPV and traumatic life events and to tailor treatment that specifically targets the effects of stress for clients who present with such a cluster of issues. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  19. High prevalence of thiamine (vitamin B1) deficiency in early childhood among a nationally representative sample of Cambodian women of childbearing age and their children

    DEFF Research Database (Denmark)

    Whitfield, Kyly C; Smith, Geoffry; Chamnan, Chhoun

    2017-01-01

    the thiamine status (measured as erythrocyte thiamine diphosphate concentrations; eThDP) among a representative sample of Cambodian women of childbearing age (15-49 y) and their young children (6-69 mo). METHODOLOGY/PRINCIPLE FINDINGS: Samples for this cross-sectional analysis were collected as part...... of a national micronutrient survey linked to the Cambodian Demographic and Health Survey (CDHS) 2014. One-sixth of households taking part in the CDHS were randomly selected and re-visited for additional blood sampling for eThDP analysis (719 women and 761 children). Thiamine status was assessed using different...... cut-offs from literature. Women were mean (SD) 30 (6) y, and children (46% girls) were 41 (17) mo. Women had lower mean (95% CI) eThDP of 150 nmol/L (146-153) compared to children, 174 nmol/L (171-179; P

  20. The Relationship between Child Abuse, Parental Divorce, and Lifetime Mental Disorders and Suicidality in a Nationally Representative Adult Sample

    Science.gov (United States)

    Afifi, Tracie O.; Boman, Jonathan; Fleisher, William; Sareen, Jitender

    2009-01-01

    Objectives: To determine how the experiences of child abuse and parental divorce are related to long-term mental health outcomes using a nationally representative adult sample after adjusting for sociodemographic variables and parental psychopathology. Methods: Data were drawn from the National Comorbidity Survey (NCS, n=5,877; age 15-54 years;…

  1. Estimates of Inequality Indices Based on Simple Random, Ranked Set, and Systematic Sampling

    OpenAIRE

    Bansal, Pooja; Arora, Sangeeta; Mahajan, Kalpana K.

    2013-01-01

    Gini index, Bonferroni index, and Absolute Lorenz index are some popular indices of inequality showing different features of inequality measurement. In general simple random sampling procedure is commonly used to estimate the inequality indices and their related inference. The key condition that the samples must be drawn via simple random sampling procedure though makes calculations much simpler but this assumption is often violated in practice as the data does not always yield simple random ...

  2. The prevalence of abnormal eating behaviour in a representative sample of the French diabetic population.

    Science.gov (United States)

    Ryan, M; Gallanagh, J; Livingstone, M B; Gaillard, C; Ritz, P

    2008-12-01

    To assess the relationship between abnormal eating behaviour (AEB) and diabetes in a sample of French adult patients with type 1 (T1D) and type 2 (T2D) diabetes. Ninety-four consecutively recruited patients self-completed a series of validated questionnaires. Over one-fourth of men with T1D (26%) or T2D (27%) and 11% of female T2D patients reported consistent and pathological overeating or binge-eating during the previous six months. Glycaemic control in these T1D patients was poorer than in T1D patients defined as normal eaters (NORM) (11.9% versus 9.6%), but did not reach statistical significance (P=0.08), and no significant difference was observed in the T2D group (P=0.61) either. T2D patients reported being markedly more restrained when eating than did the T1D patients (P=0.002), and their restraint increased along with their BMI (Phunger (P=0.02) and disinhibition (P=0.003) than did the NORM patients. AEB is present in French diabetic patients at levels that are probably higher than among the general population. These results highlight the need for: (1) greater awareness among diabetes clinicians of the problem; (2) regular screening of diabetic patients for AEB; and (3) adaptation of therapeutic and dietary recommendations for this patient subgroup.

  3. Rate and Predictors of Persistent Major Depressive Disorder in a Nationally Representative Sample.

    Science.gov (United States)

    Walker, Elizabeth Reisinger; Druss, Benjamin G

    2015-08-01

    This study examined predictors of persistent major depressive disorder over 10 years, focusing on the effects of clinical variables, physical health, and social support. Data from the National Survey of Midlife Development in the United States in 1995-1996 and 2004-2006 were analyzed. Logistic regression was used to predict non-recovery from major depression among individuals who met clinical-based criteria for major depressive disorder at baseline. Fifteen percent of the total sample was classified as having major depression in 1995-1996; of these individuals, 37 % had major depression in 2004-2006. Baseline variables that were significantly associated with persistent major depression at follow-up were being female, having never married, having two or more chronic medical conditions, experiencing activity limitation, and less contact with family. Therefore, treatment strategies focused on physical health, social support, and mental health needs are necessary to comprehensively address the factors that contribute to persistent major depressive disorder.

  4. Preliminary Blood Pressure Screening in a Representative Sample of Extremely Obese Kuwaiti Adolescents

    Directory of Open Access Journals (Sweden)

    Rima Abdul Razzak

    2013-01-01

    Full Text Available A relationship between blood pressure (BP and obesity has been found in young adults, but no data are available for adolescents in Kuwait. 257 adolescent (11–19 years participants were categorized into two groups according to their BMI; 48 nonobese (21 males: 43.7% and 27 females: 56.3% with mean age of years and 209 obese (128 males: 61.25% and 81 females: 38.75% with mean age of years. The mean BMI was  kg/m2 for the nonobese group and  kg/m3 for the obese group. Most BP measures based on a single screening were significantly higher in the obese group. The prevalence of elevated BP was significantly higher in the obese subjects (nonobese: 13%; obese: 63%; . In the obese group, there was a significant positive correlation between total sample BMI and all BP measures except the pulse pressure. There was a similar rate of elevated blood pressure between males and females (64% versus 60%; . For both isolated systolic elevated BP and isolated diastolic elevated BP, the prevalences were comparable between the males (systolic: 42%; diastolic: 5% and females (systolic: 34%; diastolic: 14%. Only systolic BP was positively correlated with BMI in obese adolescent males (Spearman ; , with a significant correlation between BMI with diastolic (Spearman ; and mean BP (Spearman ; in females.

  5. The prevalence of discrimination across racial groups in contemporary America: Results from a nationally representative sample of adults.

    Directory of Open Access Journals (Sweden)

    Brian B Boutwell

    Full Text Available A large body of social science research is devoted to understanding the causes and correlates of discrimination. Comparatively less effort has been aimed at providing a general prevalence estimate of discrimination using a nationally representative sample. The current study is intended to offer such an estimate using a large sample of American respondents (N = 14,793 while also exploring perceptions regarding why respondents felt they were discriminated against. The results provide a broad estimate of self-reported discrimination experiences-an event that was only reported by about one-quarter of all sample members-across racial and ethnic categories.

  6. The prevalence of discrimination across racial groups in contemporary America: Results from a nationally representative sample of adults

    Science.gov (United States)

    Nedelec, Joseph L.; Winegard, Bo; Shackelford, Todd; Beaver, Kevin M.; Vaughn, Michael; Barnes, J. C.; Wright, John P.

    2017-01-01

    A large body of social science research is devoted to understanding the causes and correlates of discrimination. Comparatively less effort has been aimed at providing a general prevalence estimate of discrimination using a nationally representative sample. The current study is intended to offer such an estimate using a large sample of American respondents (N = 14,793) while also exploring perceptions regarding why respondents felt they were discriminated against. The results provide a broad estimate of self-reported discrimination experiences—an event that was only reported by about one-quarter of all sample members—across racial and ethnic categories. PMID:28837680

  7. High prevalence of overweight and obesity among a representative sample of Puerto Rican children.

    Science.gov (United States)

    Elías-Boneta, Augusto R; Toro, Milagros J; Garcia, Omar; Torres, Roxana; Palacios, Cristina

    2015-03-05

    The prevalence of childhood overweight and obesity has become a public health problem worldwide. The objectives of the study were: 1) to establish the BMI prevalence in 12-year olds residing in Puerto Rico, and 2) to determine BMI differences by sex, public-private school type, and geographic regions. Data was obtained from an island-wide probabilistic stratified sample of 1,582 twelve-year-olds (53% girls and 47% boys). The BMI was determined using the National Health and Nutrition Examination Survey procedures. Children were categorized as underweight, healthy weight, overweight or obese using the Center for Disease Control and Prevention's age and gender specific growth charts. A logistic regression model was used to estimate BMI category prevalence. Odds ratios were calculated using a multinomial regression. In this study, 18.8% of the children were overweight and 24.3% were obese. A higher prevalence of obesity was observed in boys as compared to girls, 28.2% vs. 20.2%, respectively. The estimated prevalence of overweight and obesity in children from public schools was lower than for those from private schools. After adjusting for type of school and region, boys had a significantly higher risk of being obese (64%) as compared to girls. In public schools, boys had a lower prevalence of being overweight while girls had a higher prevalence compared to children attending private schools. Girls attending private schools had a higher obesity prevalence (27.8%) compared to girls from public schools (19.8%). The prevalence of underweight (2.7%) is slightly lower than in the United States. The prevalence of overweight and obesity of 12-year-olds residing in PR was 18.8% and 24.3%, respectively; higher than in the U.S. (by groups). Boys were at higher risk of obesity than girls. There is an urgent need to implement public health policies/programs to reduce the prevalence of overweight and obesity in children in PR.

  8. Validation of self-reported diabetes in a representative sample of São Paulo city

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    Mariane de Mello Fontanelli

    Full Text Available ABSTRACT OBJECTIVE To validate the self-reported diabetes mellitus in adults and older adults living in the city of São Paulo, Brazil. METHODS We have used data of 569 subjects (284 adults and 285 older adults, participants of the population-based cross-sectional study Inquérito de Saúde do Município de São Paulo (Health Survey of São Paulo. Fasting glucose ≥ 7.0 mmol/L (126 mg/dL and/or use of drugs (oral hypoglycemic and/or insulin defined the diagnosis of diabetes mellitus. We have validated the self-reported diabetes mellitus by calculating the sensitivity, specificity, positive predictive values, and negative predictive values. We have used Poisson regression with robust variance to verify the factors associated with the sensitivity of the self-reported datum. For all analyses, we have considered the sample design of the study. RESULTS The sensitivity of self-reported diabetes mellitus was 63.8% (95%CI 49.2–76.3, specificity was 99.7% (95%CI 99.1–99.9, positive predictive value was 95.5% (95%CI 84.4–98.8, and negative predictive value was 96.9% (95%CI 94.9–98.2. The correct reporting of diabetes mellitus was more prevalent among older adults (PR = 2.0; 95%CI 1.2–3.5 than among adults. CONCLUSIONS The use of the datum of self-reported diabetes mellitus is valid, especially among older adults living in the city of São Paulo. The results highlight the need to track diabetes mellitus in asymptomatic subjects who have one or more risk factors for it, mainly in the adult population of this city.

  9. Participation in Leisure Activities among Canadian Children with Arthritis: Results from a National Representative Sample.

    Science.gov (United States)

    Cavallo, Sabrina; Majnemer, Annette; Mazer, Barbara; Chilingaryan, Gevorg; Ehrmann Feldman, Debbie

    2015-06-01

    To describe the level of participation in leisure activities among children and youth with arthritis, as well as to identify the sociodemographic (age, sex, family income), disease-related (functional limitations, disease duration, pain, medication use, child's need for assistance), and contextual factors (use of rehabilitation services, proximity of local recreation facilities, cost of activities) that may be associated. Data from the Participation and Activity Limitation Survey (PALS) 2006, a Canadian postcensus survey, was analyzed. Bivariate and multivariable linear regression analyses were applied to examine the associations between the sample's level of participation in leisure activities, and sociodemographic, disease-related, and contextual characteristics. In Canada in 2006, an estimated 4350 children ranging in age from 5 to 14 years were living with arthritis. Fifty-six percent of parents reported that arthritis restricted their child's participation in leisure activities. Bivariate analysis showed that the availability of local recreational facilities, the affordability of activities, and the child not requiring any assistance were all associated (modified Bonferroni correction α leisure activities. Multiple linear regressions showed that higher family income (β 0.47, 95% CI 0.09, 0.85) and greater perceived pain (β 0.59, 95% CI 0.07, 1.10) were positively associated with involvement in informal leisure. Our findings underline the importance of considering contextual factors in developing treatment plans aimed at improving participation in leisure activities among children with arthritis. Future longitudinal studies targeting children living with arthritis could provide pertinent information on participation over fluctuations in disease status.

  10. Physical fighting among Egyptian adolescents: social and demographic correlates among a nationally representative sample

    Directory of Open Access Journals (Sweden)

    Karen L. Celedonia

    2013-08-01

    Full Text Available Introduction. Adolescent interpersonal violence is a global public health problem, yet gaps remain in the epidemiologic literature on adolescent violence in low- and middle-income countries (LMIC. Prevalence rates and risk and protective factors reported in high-income countries may be different from those reported in LMICs. Culturally-relevant epidemiologic data is important in efforts aimed at addressing adolescent interpersonal violence in these countries.Methods. A cross-sectional study of Egyptian adolescent involvement in violent behavior was conducted. Data collected from a 2006 school-based survey initiative were used; participants were adolescents aged 11–17 (N = 5, 249. Some participants were excluded from the dataset due to incomplete data (N = 111 resulting in a final sample of 5,138. Bivariate and logistic regression analyses were run to determine demographic and social variables associated with participation in physical fighting.Results. Thirty-one percent of adolescents reported being involved in a physical fight. Previously reported risk factors for violent behavior among adolescents such as depressive symptoms (OR = 1.29; CI = 1.11–1.50 and bullying victimization (OR = 2.44; CI = 2.12–2.83 were positively associated with violent behavior in the present study, while the more novel factor of sedentary behavior was also observed as having a positive association with violent behavior (OR = 1.43; CI = 1.21–1.69. Known protective factors such as helpful peers (OR = 0.75; CI = 0.62–0.90 and understanding parents (OR = 0.67; CI = 0.56–0.81 were found to have negative associations with violent behavior in the present study, in addition to the counterintuitive protective effect of having fewer friends (OR = 0.75; CI = 0.60–0.92.Conclusions. Prevalence rates of adolescent interpersonal violence in Egypt are similar to rates in other LMICs. The high reported rates of depressive symptomatology and bully victimization along with

  11. Source apportionment of population representative samples of PM(2.5) in three European cities using structural equation modelling.

    Science.gov (United States)

    Ilacqua, Vito; Hänninen, Otto; Saarela, Kristina; Katsouyanni, Klea; Künzli, Nino; Jantunen, Matti

    2007-10-01

    Apportionment of urban particulate matter (PM) to sources is central for air quality management and efficient reduction of the substantial public health risks associated with fine particles (PM(2.5)). Traffic is an important source combustion particles, but also a significant source of resuspended particles that chemically resemble Earth's crust and that are not affected by development of cleaner motor technologies. A substantial fraction of urban ambient PM originates from long-range transport outside the immediate urban environment including secondary particles formed from gaseous emissions of mainly sulphur, nitrogen oxides and ammonia. Most source apportionment studies are based on small number of fixed monitoring sites and capture well population exposures to regional and long-range transported particles. However, concentrations from local sources are very unevenly distributed and the results from such studies are therefore poorly representative of the actual exposures. The current study uses PM(2.5) data observed at population based random sampled residential locations in Athens, Basle and Helsinki with 17 elemental constituents, selected VOCs (xylenes, trimethylbenzenes, nonane and benzene) and light absorbance (black smoke). The major sources identified across the three cities included crustal, salt, long-range transported inorganic and traffic sources. Traffic was associated separately with source categories with crustal (especially Athens and Helsinki) and long-range transported chemical composition (all cities). Remarkably high fractions of the variability of elemental (R(2)>0.6 except for Ca in Basle 0.38) and chemical concentrations (R(2)>0.5 except benzene in Basle 0.22 and nonane in Athens 0.39) are explained by the source factors of an SEM model. The RAINS model that is currently used as the main tool in developing European air quality management policies seems to capture the local urban fraction (the city delta term) quite well, but underestimates

  12. Importance sampling of heavy-tailed iterated random functions

    NARCIS (Netherlands)

    B. Chen (Bohan); C.H. Rhee (Chang-Han); A.P. Zwart (Bert)

    2016-01-01

    textabstractWe consider a stochastic recurrence equation of the form $Z_{n+1} = A_{n+1} Z_n+B_{n+1}$, where $\\mathbb{E}[\\log A_1]<0$, $\\mathbb{E}[\\log^+ B_1]<\\infty$ and $\\{(A_n,B_n)\\}_{n\\in\\mathbb{N}}$ is an i.i.d. sequence of positive random vectors. The stationary distribution of this Markov

  13. Improvement of the Work Environment and Work-Related Stress: A Cross-Sectional Multilevel Study of a Nationally Representative Sample of Japanese Workers.

    Science.gov (United States)

    Watanabe, Kazuhiro; Tabuchi, Takahiro; Kawakami, Norito

    2017-03-01

    This cross-sectional multilevel study aimed to investigate the relationship between improvement of the work environment and work-related stress in a nationally representative sample in Japan. The study was based on a national survey that randomly sampled 1745 worksites and 17,500 nested employees. The survey asked the worksites whether improvements of the work environment were conducted; and it asked the employees to report the number of work-related stresses they experienced. Multilevel multinominal logistic and linear regression analyses were conducted. Improvement of the work environment was not significantly associated with any level of work-related stress. Among men, it was significantly and negatively associated with the severe level of work-related stress. The association was not significant among women. Improvements to work environments may be associated with reduced work-related stress among men nationwide in Japan.

  14. The prevalence of couple infertility in the United States from a male perspective: evidence from a nationally representative sample

    OpenAIRE

    Louis, Jean Fredo; Thoma, Marie E.; Sørensen, Ditte Nørbo; McLain, Alexander C.; King, Rosalind B.; Sundaram, Rajeshwari; Keiding, Niels; Buck Louis, Germaine M.

    2013-01-01

    Infertility is a couple based fecundity impairment, though population level research is largely based upon information reported by female partners. Of the few studies focusing on male partners, most focus on the utilization of infertility services rather than efforts to estimate the prevalence and determinants of infertility as reported by male partners. Data from a nationally-representative sample of men aged 15–44 years who participated in the 2002 National Survey of Family Growth (NSFG) we...

  15. Creating a sampling frame for population-based veteran research: Representativeness and overlap of VA and Department of Defense databases

    OpenAIRE

    Donna L. Washington, MD, MPH; Su Sun, MPH; Mark Canning, BA

    2010-01-01

    Most veteran research is conducted in Department of Veterans Affairs (VA) healthcare settings, although most veterans obtain healthcare outside the VA. Our objective was to determine the adequacy and relative contributions of Veterans Health Administration (VHA), Veterans Benefits Administration (VBA), and Department of Defense (DOD) administrative databases for representing the U.S. veteran population, using as an example the creation of a sampling frame for the National Survey of Women Vete...

  16. Child sexual abuse as a risk factor for teen dating violence: Findings from a representative sample of Quebec youth

    OpenAIRE

    Hébert, Martine; Moreau, Catherine; Blais, Martin; Lavoie, Francine; Guerrier, Mireille

    2016-01-01

    Child sexual abuse (CSA) is identified as a significant risk factor for later victimization in the context of adult intimate relationships, but less is known about the risk associated with CSA in early romantic relationships. This paper aims to document the association between CSA and teen dating victimization in a large representative sample of Quebec high-school students. As part of the Youths’ Romantic Relationships Project, 8,194 teens completed measures on CSA and psychological, physical...

  17. The Longitudinal Relation Between Peer Violent Victimization and Delinquency: Results From a National Representative Sample of U.S. Adolescents

    OpenAIRE

    Jackson, Corrie L.; Hanson, Rochelle F.; Amstadter, Ananda B.; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2012-01-01

    Using a nationally representative sample of adolescents from the United States aged 12 to 17 years (Wave 1, n = 3,614; Wave 2, n = 2,511), this study examined (a) demographic and descriptive information about peer violent victimization (PVV); and (b) the longitudinal relation between a history of PVV and delinquency. Results indicated that 12.4% of adolescents reported lifetime exposure to PVV, and many of these adolescents with a previous history of PVV also reported exposure to other forms ...

  18. Dating of a representative pottery sample from the basin of Sayula, Jalisco in Mexico using the thermoluminescence method

    Energy Technology Data Exchange (ETDEWEB)

    Mercado U, H. [CINVESTAV, Unidad Monterrey, Nuevo Leon (Mexico); Schaaf, P.; Ramirez, A. [Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico); Gonzalez, P.R. [ININ, 52750 Ocoyoacac, Estado de Mexico (Mexico); Brunet, J. [CUCSH, Universidad de Guadalajara, Jalisco (Mexico)

    2006-07-01

    In this work is presented a study of dating of the representative pottery sample from the west of Mexico, in a predominantly saline region. The study is carried out with the thermoluminescence method and the fine grain technique. The archaeological region was begun to study from 1990. This work also presents an historical and geographical context of the region and its relevance in the western culture of Mexico. (Author)

  19. Dating of a representative pottery sample from the basin of Sayula, Jalisco in Mexico using the thermoluminescence method

    International Nuclear Information System (INIS)

    Mercado U, H.; Schaaf, P.; Ramirez, A.; Gonzalez, P.R.; Brunet, J.

    2006-01-01

    In this work is presented a study of dating of the representative pottery sample from the west of Mexico, in a predominantly saline region. The study is carried out with the thermoluminescence method and the fine grain technique. The archaeological region was begun to study from 1990. This work also presents an historical and geographical context of the region and its relevance in the western culture of Mexico. (Author)

  20. Representativeness of two sampling procedures for an internet intervention targeting cancer-related distress: a comparison of convenience and registry samples.

    Science.gov (United States)

    Owen, Jason E; Bantum, Erin O'Carroll; Criswell, Kevin; Bazzo, Julie; Gorlick, Amanda; Stanton, Annette L

    2014-08-01

    Internet interventions often rely on convenience sampling, yet convenience samples may differ in important ways from systematic recruitment approaches. The purpose of this study was to evaluate potential demographic, medical, and psychosocial differences between Internet-recruited and registry-recruited cancer survivors in an Internet-based intervention. Participants were recruited from a cancer registry (n = 80) and via broad Internet outreach efforts (n = 160). Participants completed a set of self-report questionnaires, and both samples were compared to a population-based sample of cancer survivors (n = 5,150). The Internet sample was younger, better educated, more likely to be female, had longer time since diagnosis, and had more advanced stage of disease (p's sample was over-represented by men and those with prostate or other cancer types (p's sample also exhibited lower quality of life and social support and greater mood disturbance (p's convenience and systematic samples differ has important implications for external validity and potential for dissemination of Internet-based interventions.

  1. Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

    Directory of Open Access Journals (Sweden)

    Andrea A Andrew

    2016-02-01

    Full Text Available Some properties of dissolved organic matter (DOM and chromophoric dissolved organic matter (CDOM can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB and the Equatorial Atlantic Ocean (EAO. Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4.C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  2. Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

    Science.gov (United States)

    Andrew, Andrea; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil

    2016-02-01

    Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  3. Are Extracted Materials Truly Representative of Original Samples? Impact of C18 Extraction on CDOM Optical and Chemical Properties.

    Science.gov (United States)

    Andrew, Andrea A; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil V

    2016-01-01

    Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction (SPE) is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission, and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  4. Radial line-scans as representative sampling strategy in dried-droplet laser ablation of liquid samples deposited on pre-cut filter paper disks

    Energy Technology Data Exchange (ETDEWEB)

    Nischkauer, Winfried [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna (Austria); Department of Analytical Chemistry, Ghent University, Ghent (Belgium); Vanhaecke, Frank [Department of Analytical Chemistry, Ghent University, Ghent (Belgium); Bernacchi, Sébastien; Herwig, Christoph [Institute of Chemical Engineering, Vienna University of Technology, Vienna (Austria); Limbeck, Andreas, E-mail: Andreas.Limbeck@tuwien.ac.at [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna (Austria)

    2014-11-01

    Nebulising liquid samples and using the aerosol thus obtained for further analysis is the standard method in many current analytical techniques, also with inductively coupled plasma (ICP)-based devices. With such a set-up, quantification via external calibration is usually straightforward for samples with aqueous or close-to-aqueous matrix composition. However, there is a variety of more complex samples. Such samples can be found in medical, biological, technological and industrial contexts and can range from body fluids, like blood or urine, to fuel additives or fermentation broths. Specialized nebulizer systems or careful digestion and dilution are required to tackle such demanding sample matrices. One alternative approach is to convert the liquid into a dried solid and to use laser ablation for sample introduction. Up to now, this approach required the application of internal standards or matrix-adjusted calibration due to matrix effects. In this contribution, we show a way to circumvent these matrix effects while using simple external calibration for quantification. The principle of representative sampling that we propose uses radial line-scans across the dried residue. This compensates for centro-symmetric inhomogeneities typically observed in dried spots. The effectiveness of the proposed sampling strategy is exemplified via the determination of phosphorus in biochemical fermentation media. However, the universal viability of the presented measurement protocol is postulated. Detection limits using laser ablation-ICP-optical emission spectrometry were in the order of 40 μg mL{sup −1} with a reproducibility of 10 % relative standard deviation (n = 4, concentration = 10 times the quantification limit). The reported sensitivity is fit-for-purpose in the biochemical context described here, but could be improved using ICP-mass spectrometry, if future analytical tasks would require it. Trueness of the proposed method was investigated by cross-validation with

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

    Science.gov (United States)

    Kaspi, Omer; Yosipof, Abraham; Senderowitz, Hanoch

    2017-06-06

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

  6. Gambling Type, Substance Abuse, Health and Psychosocial Correlates of Male and Female Problem Gamblers in a Nationally Representative French Sample.

    Science.gov (United States)

    Bonnaire, C; Kovess-Masfety, V; Guignard, R; Richard, J B; du Roscoät, E; Beck, F

    2017-06-01

    Many studies carried out on treatment-seeking problem gamblers (PG) have reported high levels of comorbid substance use disorders, and mental and physical health problems. Nevertheless, general population studies are still sparse, most of them have been carried out in the United States or Canada, and gender differences have not always been considered. Thus, the aim of this study was to describe the type of games, and psychological and physical correlates in male and female PG in a nationally representative French sample. The total sample studied involved 25,647 subjects aged 15-85 years, including 333 PG and 25,314 non-problem gamblers (NPG). Data were extracted from a large survey of a representative sample of the French general population. They were evaluated for sociodemographic variables, gambling behavior, type of gambling activity, substance use, psychological distress, body mass index, chronic disease, and lack of sleep. Overall, there were significant differences between PG and NPG in gender, age, education, employment and marital status, substance use disorders (alcohol, tobacco, cannabis, cocaine and heroin), psychological distress, obesity, lack of sleep and type of gambling activity. Although male and female PG had different profiles, the gambling type, especially strategic games, appeared as an important variable in the relationship between gender and problem gambling. This research underlines the importance of considering gender differences and gambling type in the study of gambling disorders. Identifying specific factors in the relationship between gender, gambling type and gambling problems may help improve clinical interventions and health promotion strategies.

  7. Determination of a representative volume element based on the variability of mechanical properties with sample size in bread.

    Science.gov (United States)

    Ramírez, Cristian; Young, Ashley; James, Bryony; Aguilera, José M

    2010-10-01

    Quantitative analysis of food structure is commonly obtained by image analysis of a small portion of the material that may not be the representative of the whole sample. In order to quantify structural parameters (air cells) of 2 types of bread (bread and bagel) the concept of representative volume element (RVE) was employed. The RVE for bread, bagel, and gelatin-gel (used as control) was obtained from the relationship between sample size and the coefficient of variation, calculated from the apparent Young's modulus measured on 25 replicates. The RVE was obtained when the coefficient of variation for different sample sizes converged to a constant value. In the 2 types of bread tested, the tendency of the coefficient of variation was to decrease as the sample size increased, while in the homogeneous gelatin-gel, it remained always constant around 2.3% to 2.4%. The RVE resulted to be cubes with sides of 45 mm for bread, 20 mm for bagels, and 10 mm for gelatin-gel (smallest sample tested). The quantitative image analysis as well as visual observation demonstrated that bread presented the largest dispersion of air-cell sizes. Moreover, both the ratio of maximum air-cell area/image area and maximum air-cell height/image height were greater for bread (values of 0.05 and 0.30, respectively) than for bagels (0.03 and 0.20, respectively). Therefore, the size and the size variation of air cells present in the structure determined the size of the RVE. It was concluded that RVE is highly dependent on the heterogeneity of the structure of the types of baked products.

  8. An alternative procedure for estimating the population mean in simple random sampling

    Directory of Open Access Journals (Sweden)

    Housila P. Singh

    2012-03-01

    Full Text Available This paper deals with the problem of estimating the finite population mean using auxiliary information in simple random sampling. Firstly we have suggested a correction to the mean squared error of the estimator proposed by Gupta and Shabbir [On improvement in estimating the population mean in simple random sampling. Jour. Appl. Statist. 35(5 (2008, pp. 559-566]. Later we have proposed a ratio type estimator and its properties are studied in simple random sampling. Numerically we have shown that the proposed class of estimators is more efficient than different known estimators including Gupta and Shabbir (2008 estimator.

  9. Health plan auditing: 100-percent-of-claims vs. random-sample audits.

    Science.gov (United States)

    Sillup, George P; Klimberg, Ronald K

    2011-01-01

    The objective of this study was to examine the relative efficacy of two different methodologies for auditing self-funded medical claim expenses: 100-percent-of-claims auditing versus random-sampling auditing. Multiple data sets of claim errors or 'exceptions' from two Fortune-100 corporations were analysed and compared to 100 simulated audits of 300- and 400-claim random samples. Random-sample simulations failed to identify a significant number and amount of the errors that ranged from $200,000 to $750,000. These results suggest that health plan expenses of corporations could be significantly reduced if they audited 100% of claims and embraced a zero-defect approach.

  10. Radial line-scans as representative sampling strategy in dried-droplet laser ablation of liquid samples deposited on pre-cut filter paper disks

    Science.gov (United States)

    Nischkauer, Winfried; Vanhaecke, Frank; Bernacchi, Sébastien; Herwig, Christoph; Limbeck, Andreas

    2014-11-01

    Nebulising liquid samples and using the aerosol thus obtained for further analysis is the standard method in many current analytical techniques, also with inductively coupled plasma (ICP)-based devices. With such a set-up, quantification via external calibration is usually straightforward for samples with aqueous or close-to-aqueous matrix composition. However, there is a variety of more complex samples. Such samples can be found in medical, biological, technological and industrial contexts and can range from body fluids, like blood or urine, to fuel additives or fermentation broths. Specialized nebulizer systems or careful digestion and dilution are required to tackle such demanding sample matrices. One alternative approach is to convert the liquid into a dried solid and to use laser ablation for sample introduction. Up to now, this approach required the application of internal standards or matrix-adjusted calibration due to matrix effects. In this contribution, we show a way to circumvent these matrix effects while using simple external calibration for quantification. The principle of representative sampling that we propose uses radial line-scans across the dried residue. This compensates for centro-symmetric inhomogeneities typically observed in dried spots. The effectiveness of the proposed sampling strategy is exemplified via the determination of phosphorus in biochemical fermentation media. However, the universal viability of the presented measurement protocol is postulated. Detection limits using laser ablation-ICP-optical emission spectrometry were in the order of 40 μg mL- 1 with a reproducibility of 10 % relative standard deviation (n = 4, concentration = 10 times the quantification limit). The reported sensitivity is fit-for-purpose in the biochemical context described here, but could be improved using ICP-mass spectrometry, if future analytical tasks would require it. Trueness of the proposed method was investigated by cross-validation with

  11. Testing the main prediction of the Interpersonal Theory of Suicide in a representative sample of the German general population.

    Science.gov (United States)

    Glaesmer, Heide; Hallensleben, Nina; Forkmann, Thomas; Spangenberg, Lena; Kapusta, Nestor; Teismann, Tobias

    2017-03-15

    To evaluate the main prediction of the Interpersonal Theory of Suicide (IPTS): 3-way-interaction of perceived burdensomeness (PB), thwarted belongingness (TB), and acquired capability (AC) for the prediction of suicidal behavior in a representative population sample. A total of 2513 participants completed measures of suicidal behavior, TB, PB, acquired capability (AC-FAD), and symptoms of depression and anxiety. The two-way-interaction of TB and PB, and the three-way interaction of TB, PB and AC-FAD predict suicidality. Given the cross-sectional nature of the data, conclusions on causality should be handled carefully. The main prediction of the IPTS has been proven in a general population sample. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The Cycle of Violence: Examining Attitudes Toward and Experiences of Corporal Punishment in a Representative German Sample.

    Science.gov (United States)

    Witt, Andreas; Fegert, Jörg M; Rodens, Klaus P; Brähler, Elmar; Lührs Da Silva, Claudia; Plener, Paul L

    2017-09-01

    The use of corporal punishment (CP) is controversial despite the negative consequences of its use that have been documented. Consequences include the use of CP by those who experienced CP themselves, described in the theory of the cycle of violence. There are little data on the cycle of violence, especially on those who break it and in representative samples. This study examines the cycle of violence in a representative sample by analyzing experiences of and attitudes toward CP. Attitudes toward, and own experiences of, CP by their parents were assessed in a sample of 2,519 individuals (female 54.6%, age range = 14-99 years, M = 48.9 years). Latent class analysis (LCA) was used to identify subgroups of participants who support and oppose CP. Breaking the cycle, defined as having experienced CP and opposing CP, was examined. Factors associated with positive and negative attitudes toward CP were identified using group comparisons and binary logistic regression. The majority of the sample opposed CP (56%), whereas one third supported less severe forms of CP and 8.2% also supported severe CP. Those supporting CP reported having experienced CP by their parents more often. Of those who had experienced CP, 47% were identified as breaking the cycle. Female gender, younger age, not being divorced, and being married and living together, as well as a higher level of education were associated with breaking the cycle. Even though CP was legally banned in Germany, a relatively high proportion still reports positive attitudes toward and experiences of CP. The ban of CP by the federal government seems to be an effective measure to change attitudes on a societal level as rates were lower in comparison with earlier studies. Future studies should examine interactions between different types of CP, attitudes toward its use, and additional mediating factors.

  13. 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...

  14. Relationship between attitudes towards healthy eating and dietary behaviour, lifestyle and demographic factors in a representative sample of Irish adults.

    Science.gov (United States)

    Hearty, A P; McCarthy, S N; Kearney, J M; Gibney, M J

    2007-01-01

    Attitudes towards healthy eating were explored according to dietary, lifestyle and socio-demographic correlates in a random sample of 1256 Irish adults. Data were obtained from an Irish cross-sectional survey (1997-1999). A self-administered questionnaire was used to obtain attitudinal information. Food consumption was estimated using a 7-d food diary. A majority of the sample had a positive attitude or motivation towards their healthy eating behaviour. Those who perceived their own eating habits to be healthy were more likely to comply with current dietary guidelines than those who did not. Females, increasing age, higher social class, tertiary education, non-smokers, lower body-weights and increased recreational activity were associated with a lower odds ratio (OR) for having a negative attitude towards their healthy eating behaviour. An increased intake (g/d) of breakfast cereals, vegetables, fruit and poultry dishes were associated with decreased OR for negative attitudes towards their healthy eating behaviour, while an increased intake of high-calorie beverages (g/d) was associated with an increased OR. It can be concluded that attitudes or motivation towards eating healthily was related to measured dietary and lifestyle behaviour in this sample. Future research is warranted to devise appropriate methods of instituting attitude change towards dietary behaviour in certain subgroups of the population.

  15. Association Between Objectively Measured Physical Activity and Erectile Dysfunction among a Nationally Representative Sample of American Men.

    Science.gov (United States)

    Loprinzi, Paul D; Edwards, Meghan

    2015-09-01

    Emerging work suggests an inverse association between physical activity and erectile dysfunction (ED). The majority of this cross-sectional research comes from convenience samples and all studies on this topic have employed self-report physical activity methodology. Therefore, the purpose of this brief-report, confirmatory research study was to examine the association between objectively measured physical activity and ED in a national sample of Americans. Data from the 2003-2004 National Health and Nutrition Examination Survey were used. Six hundred ninety-two adults between the ages of 50 and 85 years (representing 33.2 million adults) constituted the analytic sample. Participants wore an ActiGraph 7164 accelerometer (ActiGraph, Pensacola, FL, USA) for up to 7 days with ED assessed via self-report. The main outcome measure used was ED assessed via self-report. After adjustments, for every 30 min/day increase in moderate-to-vigorous physical activity, participants had a 43% reduced odds of having ED (odds ratioadjusted  = 0.57; 95% confidence interval: 0.40-0.81; P = 0.004). This confirmatory study employing an objective measure of physical activity in a national sample suggests an inverse association between physical activity and ED. © 2015 International Society for Sexual Medicine.

  16. Forecasting elections with mere recognition from small, lousy samples: A comparison of collective recognition, wisdom of crowds, and representative polls

    Directory of Open Access Journals (Sweden)

    Wolfgang Gaissmeier

    2011-02-01

    Full Text Available We investigated the extent to which the human capacity for recognition helps to forecast political elections: We compared naive recognition-based election forecasts computed from convenience samples of citizens' recognition of party names to (i standard polling forecasts computed from representative samples of citizens' voting intentions, and to (ii simple---and typically very accurate---wisdom-of-crowds-forecasts computed from the same convenience samples of citizens' aggregated hunches about election results. Results from four major German elections show that mere recognition of party names forecast the parties' electoral success fairly well. Recognition-based forecasts were most competitive with the other models when forecasting the smaller parties' success and for small sample sizes. However, wisdom-of-crowds-forecasts outperformed recognition-based forecasts in most cases. It seems that wisdom-of-crowds-forecasts are able to draw on the benefits of recognition while at the same time avoiding its downsides, such as lack of discrimination among very famous parties or recognition caused by factors unrelated to electoral success. Yet it seems that a simple extension of the recognition-based forecasts---asking people what proportion of the population would recognize a party instead of whether they themselves recognize it---is also able to eliminate these downsides.

  17. Psychometric properties of the Hare Psychopathy Checklist-Revised (PCL-R) in a representative sample of Canadian federal offenders.

    Science.gov (United States)

    Storey, Jennifer E; Hart, Stephen D; Cooke, David J; Michie, Christine

    2016-04-01

    The Hare Psychopathy Checklist-Revised (PCL-R; Hare, 2003) is a commonly used psychological test for assessing traits of psychopathic personality disorder. Despite the abundance of research using the PCL-R, the vast majority of research used samples of convenience rather than systematic methods to minimize sampling bias and maximize the generalizability of findings. This potentially complicates the interpretation of test scores and research findings, including the "norms" for offenders from the United States and Canada included in the PCL-R manual. In the current study, we evaluated the psychometric properties of PCL-R scores for all male offenders admitted to a regional reception center of the Correctional Service of Canada during a 1-year period (n = 375). Because offenders were admitted for assessment prior to institutional classification, they comprise a sample that was heterogeneous with respect to correctional risks and needs yet representative of all offenders in that region of the service. We examined the distribution of PCL-R scores, classical test theory indices of its structural reliability, the factor structure of test items, and the external correlates of test scores. The findings were highly consistent with those typically reported in previous studies. We interpret these results as indicating it is unlikely any sampling limitations of past research using the PCL-R resulted in findings that were, overall, strongly biased or unrepresentative. (c) 2016 APA, all rights reserved).

  18. Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling.

    Science.gov (United States)

    Kim, Taehong; O'Neal, Dennis L; Ortiz, Carlos

    2006-09-01

    Air duct systems in nuclear facilities must be monitored with continuous sampling in case of an accidental release of airborne radionuclides. The purpose of this work is to identify the air sampling locations where the velocity and contaminant concentrations fall below the 20% coefficient of variation required by the American National Standards Institute/Health Physics Society N13.1-1999. Experiments of velocity and tracer gas concentration were conducted on a generic "T" mixing system which included combinations of three sub ducts, one main duct, and air velocities from 0.5 to 2 m s (100 to 400 fpm). The experimental results suggest that turbulent mixing provides the accepted velocity coefficients of variation after 6 hydraulic diameters downstream of the T-junction. About 95% of the cases achieved coefficients of variation below 10% by 6 hydraulic diameters. However, above a velocity ratio (velocity in the sub duct/velocity in the main duct) of 2, velocity profiles were uniform in a shorter distance downstream of the T-junction as the velocity ratio went up. For the tracer gas concentration, the distance needed for the coefficients of variation to drop 20% decreased with increasing velocity ratio due to the sub duct airflow momentum. The results may apply to other duct systems with similar geometries and, ultimately, be a basis for selecting a proper sampling location under the requirements of single point representative sampling.

  19. Validation of the Narcissistic Admiration and Rivalry Questionnaire Short Scale (NARQ-S) in convenience and representative samples.

    Science.gov (United States)

    Leckelt, Marius; Wetzel, Eunike; Gerlach, Tanja M; Ackerman, Robert A; Miller, Joshua D; Chopik, William J; Penke, Lars; Geukes, Katharina; Küfner, Albrecht C P; Hutteman, Roos; Richter, David; Renner, Karl-Heinz; Allroggen, Marc; Brecheen, Courtney; Campbell, W Keith; Grossmann, Igor; Back, Mitja D

    2018-01-01

    Due to increased empirical interest in narcissism across the social sciences, there is a need for inventories that can be administered quickly while also reliably measuring both the agentic and antagonistic aspects of grandiose narcissism. In this study, we sought to validate the factor structure, provide representative descriptive data and reliability estimates, assess the reliability across the trait spectrum, and examine the nomological network of the short version of the Narcissistic Admiration and Rivalry Questionnaire (NARQ-S; Back et al., 2013). We used data from a large convenience sample (total N = 11,937) as well as data from a large representative sample (total N = 4,433) that included responses to other narcissism measures as well as related constructs, including the other Dark Triad traits, Big Five personality traits, and self-esteem. Confirmatory factor analysis and item response theory were used to validate the factor structure and estimate the reliability across the latent trait spectrum, respectively. Results suggest that the NARQ-S shows a robust factor structure and is a reliable and valid short measure of the agentic and antagonistic aspects of grandiose narcissism. We also discuss future directions and applications of the NARQ-S as a short and comprehensive measure of grandiose narcissism. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  20. Dietary Risk Factors by Race/Ethnicity, Age-Group, and Gender in a Representative Sample of US Older Adults.

    Science.gov (United States)

    Vaccaro, J A; Huffman, F G

    2017-01-01

    To explore the relationships among ethnicity/race, gender, demographics, age-group and dietary health in a nationally representative sample of older adults. Cross-sectional study. Data for this study were collected by interview in the mobile examination centers from the National Health and Nutrition Examination Surveys, 2011 - 2012. U.S. representative sample of adults aged 55 years and older (N = 1860) from five ethnic/racial groups. All participants read, understood, and signed informed consent forms under data collection procedures by trained individuals. Sociodemographics were collected by trained interviewers using a general questionnaire. Food groups were determined by 24-hour recall using the validated USDA Automated Multiple-Pass Method. Data were presented by cross-tabulation and logistic regression to investigate relationships among race/ethnicity, gender, and age groups. Over 70% of older adults failed to consume 2.75 cups of combined fruits and vegetables. Other Hispanics (Hispanics excluding Mexican Americans) had higher Odds of sugar-containing food consumption compared to non-Hispanic Whites (adjusted model). Being older and female were protective factors for over-consumption of sugar. Older Americans are not meeting dietary guidelines and there are differences by gender and ethnicity. Since diet has been associated with quality of life and medical costs, public health interventions can benefit by knowing age-, gender- and racial/ethnic- specific dietary behaviors.

  1. Concurrent and simultaneous polydrug use: latent class analysis of an Australian nationally representative sample of young adults.

    Directory of Open Access Journals (Sweden)

    Lake-Hui eQuek

    2013-11-01

    Full Text Available Background: Alcohol use and illicit drug use peak during young adulthood (around 18-29 years of age, but comparatively little is known about polydrug use in nationally representative samples of young adults. Drawing on a nationally representative cross-sectional survey (Australian National Drug Strategy Household Survey, this study examines polydrug use patterns and associated psychosocial risk factors among young adults (n = 3,333; age 19-29. Method: The use of a broad range of licit and illicit drugs were examined, including alcohol, tobacco, cannabis, cocaine, hallucinogens, ecstasy, ketamine, GHB, inhalants, steroids, barbiturates, meth/amphetamines, heroin, methadone/buprenorphine, other opiates, painkillers and tranquillizers/sleeping pills. Latent class analysis was employed to identify patterns of polydrug use. Results: Polydrug use in this sample was best described using a 5-class solution. The majority of young adults predominantly used alcohol only (52.3%, alcohol and tobacco (34.18%. The other classes were cannabis, ecstasy, and licit drug use (9.4%, cannabis, amphetamine derivative, and licit drug use (2.8%, and sedative and alcohol use (1.3%. Young adult males with low education and/or high income were most at risk of polydrug use. Conclusion: Almost half of young adults reported polydrug use, highlighting the importance of post-high school screening for key risk factors and polydrug use profiles, and the delivery of early intervention strategies targeting illicit drugs.

  2. Investigating the link between liking versus wanting self-esteem and depression in a nationally representative sample of American adults.

    Science.gov (United States)

    Bushman, Brad J; Moeller, Scott J; Konrath, Sara; Crocker, Jennifer

    2012-10-01

    The self-esteem movement has been around since the 1970s, and may have influenced how much value people place on self-esteem. We predicted a negative relationship between age and the amount of value placed on self-esteem boosts. We also investigated the correlates of liking versus wanting self-esteem boosts (and other pleasant rewards) on depression. A nationally representative sample of American adults (N = 867) indicated how much they liked and wanted several pleasant rewards (i.e., sex, food, alcohol, money, friendship, self-esteem boost). They also completed a standardized measure of depressive symptoms. As expected, there was a negative relationship between age and valuing self-esteem boosts, sex, and alcohol. People with depressive symptoms wanted self-esteem boosts, even though they did not like them very much. Similar effects were obtained for depressive symptoms and alcohol and friendship. This is the first research to show that self-esteem boosts are more valued among a nationally representative sample of younger American adults. It also is the first research to explore the association between depression and the motivation to boost self-esteem. People with depressive symptoms want self-esteem, and may pursue it, but this pursuit may feel unrewarding because they do not derive pleasure from it. © 2012 The Authors. Journal of Personality © 2012, Wiley Periodicals, Inc.

  3. Victimization and adversity among children experiencing war-related parental absence or deployment in a nationally representative US sample.

    Science.gov (United States)

    Turner, Heather A; Finkelhor, David; Hamby, Sherry; Henly, Megan

    2017-05-01

    This study compares children and youth who have experienced lifetime war-related parental absence or deployment with those having no such history on a variety of victimization types, non-victimization adversity, trauma symptoms, and delinquency; and assesses whether cumulative adversity and victimization help to explain elevated emotional and behavioral problems among children of parents who have experienced war-related absence or deployment. The National Surveys of Children's Exposure to Violence (NatSCEV) are comprised of three cross-sectional telephone surveys conducted in 2008, 2011, and 2014. Data were collected on the experiences of children aged one month to seventeen years. In each survey, interviews were conducted with youth 10-17 years old and with caregivers of children 0-9 years old. The analyses use pooled data from all three U.S. nationally-representative samples (total sample size of 13,052). Lifetime parental war-related absence or deployment was a marker for elevated childhood exposure to a wide array of victimization and adversity types. Cumulative past year exposure to multiple forms of victimization and adversity fully explained elevated trauma symptoms and delinquency in this population of children. Given the breadth of victimization and adversity risk, children with histories of parental war-related absence or deployment, as well as their families, represent important target groups for broad-based prevention and interventions to reduce exposure and ameliorate consequences when it does occur. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Optimism is universal: exploring the presence and benefits of optimism in a representative sample of the world.

    Science.gov (United States)

    Gallagher, Matthew W; Lopez, Shane J; Pressman, Sarah D

    2013-10-01

    Current theories of optimism suggest that the tendency to maintain positive expectations for the future is an adaptive psychological resource associated with improved well-being and physical health, but the majority of previous optimism research has been conducted in industrialized nations. The present study examined (a) whether optimism is universal, (b) what demographic factors predict optimism, and (c) whether optimism is consistently associated with improved subjective well-being and perceived health worldwide. The present study used representative samples of 142 countries that together represent 95% of the world's population. The total sample of 150,048 individuals had a mean age of 38.28 (SD = 16.85) and approximately equal sex distribution (51.2% female). The relationships between optimism, subjective well-being, and perceived health were examined using hierarchical linear modeling. Results indicated that most individuals and most countries worldwide are optimistic and that higher levels of optimism are associated with improved subjective well-being and perceived health worldwide. The present study provides compelling evidence that optimism is a universal phenomenon and that the associations between optimism and improved psychological functioning are not limited to industrialized nations. © 2012 Wiley Periodicals, Inc.

  5. Protection motivation theory and physical activity: a longitudinal test among a representative population sample of Canadian adults.

    Science.gov (United States)

    Plotnikoff, Ronald C; Rhodes, Ryan E; Trinh, Linda

    2009-11-01

    The purpose of this study was to examine the Protection Motivation Theory (PMT) to predict physical activity (PA) behaviour in a large, population-based sample of adults. One thousand six hundred and two randomly selected individuals completed two telephone interviews over two consecutive six-month periods assessing PMT constructs. PMT explained 35 per cent and 20 per cent of the variance in intention and behaviour respectively. Coping cognitions as moderators of threat explained 1 per cent of the variance in intention and behaviour. Age and gender as moderators of threat did not provide additional variance in the models. We conclude that salient PMT predictors (e.g. self-efficacy) may guide the development of effective PA interventions in the general population.

  6. Acrolein and asthma attack prevalence in a representative sample of the United States adult population 2000-2009.

    Science.gov (United States)

    deCastro, B Rey

    2014-01-01

    Acrolein is an air toxic and highly potent respiratory irritant. There is little epidemiology available, but US EPA estimates that outdoor acrolein is responsible for about 75 percent of non-cancer respiratory health effects attributable to air toxics in the United States, based on the Agency's 2005 NATA (National-Scale Air Toxics Assessment) and acrolein's comparatively potent inhalation reference concentration of 0.02 µg/m3. Assess the association between estimated outdoor acrolein exposure and asthma attack reported by a representative cross-sectional sample of the adult United States population. NATA 2005 chronic outdoor acrolein exposure estimates at the census tract were linked with residences oif adults (≥18 years old) in the NHIS (National Health Interview Survey) 2000-2009 (n = 271,348 subjects). A sample-weighted logistic regression model characterized the association between the prevalence of reporting at least one asthma attack in the 12 months prior to survey interview and quintiles of exposure to outdoor acrolein, controlling for potential confounders. In the highest quintile of outdoor acrolein exposure (0.05-0.46 µg/m3), there was a marginally significant increase in the asthma attack pOR (prevalence-odds ratio [95% CI]  = 1.08 [0.98∶1.19]) relative to the lowest quintile. The highest quintile was also associated with a marginally significant increase in prevalence-odds (1.13 [0.98∶1.29]) in a model limited to never smokers (n = 153,820). Chronic exposure to outdoor acrolein of 0.05-0.46 µg/m3 appears to increase the prevalence-odds of having at least one asthma attack in the previous year by 8 percent in a representative cross-sectional sample of the adult United States population.

  7. Acrolein and Asthma Attack Prevalence in a Representative Sample of the United States Adult Population 2000 – 2009

    Science.gov (United States)

    deCastro, B. Rey

    2014-01-01

    Background Acrolein is an air toxic and highly potent respiratory irritant. There is little epidemiology available, but US EPA estimates that outdoor acrolein is responsible for about 75 percent of non-cancer respiratory health effects attributable to air toxics in the United States, based on the Agency's 2005 NATA (National-Scale Air Toxics Assessment) and acrolein's comparatively potent inhalation reference concentration of 0.02 µg/m3. Objectives Assess the association between estimated outdoor acrolein exposure and asthma attack reported by a representative cross-sectional sample of the adult United States population. Methods NATA 2005 chronic outdoor acrolein exposure estimates at the census tract were linked with residences oif adults (≥18 years old) in the NHIS (National Health Interview Survey) 2000 – 2009 (n = 271,348 subjects). A sample-weighted logistic regression model characterized the association between the prevalence of reporting at least one asthma attack in the 12 months prior to survey interview and quintiles of exposure to outdoor acrolein, controlling for potential confounders. Results In the highest quintile of outdoor acrolein exposure (0.05 – 0.46 µg/m3), there was a marginally significant increase in the asthma attack pOR (prevalence-odds ratio [95% CI]  = 1.08 [0.98∶1.19]) relative to the lowest quintile. The highest quintile was also associated with a marginally significant increase in prevalence-odds (1.13 [0.98∶1.29]) in a model limited to never smokers (n = 153,820). Conclusions Chronic exposure to outdoor acrolein of 0.05 – 0.46 µg/m3 appears to increase the prevalence-odds of having at least one asthma attack in the previous year by 8 percent in a representative cross-sectional sample of the adult United States population. PMID:24816802

  8. Acrolein and asthma attack prevalence in a representative sample of the United States adult population 2000-2009.

    Directory of Open Access Journals (Sweden)

    B Rey deCastro

    Full Text Available BACKGROUND: Acrolein is an air toxic and highly potent respiratory irritant. There is little epidemiology available, but US EPA estimates that outdoor acrolein is responsible for about 75 percent of non-cancer respiratory health effects attributable to air toxics in the United States, based on the Agency's 2005 NATA (National-Scale Air Toxics Assessment and acrolein's comparatively potent inhalation reference concentration of 0.02 µg/m3. OBJECTIVES: Assess the association between estimated outdoor acrolein exposure and asthma attack reported by a representative cross-sectional sample of the adult United States population. METHODS: NATA 2005 chronic outdoor acrolein exposure estimates at the census tract were linked with residences oif adults (≥18 years old in the NHIS (National Health Interview Survey 2000-2009 (n = 271,348 subjects. A sample-weighted logistic regression model characterized the association between the prevalence of reporting at least one asthma attack in the 12 months prior to survey interview and quintiles of exposure to outdoor acrolein, controlling for potential confounders. RESULTS: In the highest quintile of outdoor acrolein exposure (0.05-0.46 µg/m3, there was a marginally significant increase in the asthma attack pOR (prevalence-odds ratio [95% CI]  = 1.08 [0.98∶1.19] relative to the lowest quintile. The highest quintile was also associated with a marginally significant increase in prevalence-odds (1.13 [0.98∶1.29] in a model limited to never smokers (n = 153,820. CONCLUSIONS: Chronic exposure to outdoor acrolein of 0.05-0.46 µg/m3 appears to increase the prevalence-odds of having at least one asthma attack in the previous year by 8 percent in a representative cross-sectional sample of the adult United States population.

  9. Social and psychological resources associated with health status in a representative sample of adults affected by the 2004 Florida hurricanes.

    Science.gov (United States)

    Ruggiero, Kenneth J; Amstadter, Ananda B; Acierno, Ron; Kilpatrick, Dean G; Resnick, Heidi S; Tracy, Melissa; Galea, Sandro

    2009-01-01

    Overall health status after a disaster may be associated with long-term physical morbidity and mortality. Little is known about factors associated with overall health status in the aftermath of disasters. We examined self-rated health in relation to disaster characteristics, social resources, and post-disaster outcomes in a sample of adults who experienced the 2004 Florida hurricanes. We interviewed a representative sample of 1,452 adults aged 18 years and older residing in the 33 Florida counties that were in the direct path of at least one of the 2004 hurricanes (Charley, Frances, Ivan, Jeanne). Overall health status was assessed using a self-rating format known to be predictive of mortality. Poor self-rated health was endorsed by 14.6% of the sample. Final multivariable models showed that poor self-rated health was associated with older age (p hurricane (p = 0.03), low social support (p = 0.03), and depression (p = 0.003) since the hurricane. Self-rated health following the Florida hurricanes was strongly associated with two variables (social support and depression) that potentially can be mitigated through targeted interventions after disasters. Future work should evaluate secondary prevention strategies that can address general health-related concerns in the wake of a disaster.

  10. Health Correlates of Insomnia Symptoms and Comorbid Mental Disorders in a Nationally Representative Sample of US Adolescents

    Science.gov (United States)

    Blank, Madeleine; Zhang, Jihui; Lamers, Femke; Taylor, Adrienne D.; Hickie, Ian B.; Merikangas, Kathleen R.

    2015-01-01

    Study Objectives: To estimate the prevalence and health correlates of insomnia symptoms and their association with comorbid mental disorders in a nationally representative sample of adolescents in the United States. Design: National representative cross-sectional study. Setting: Population-based sample from the US adolescents. Measurements and Results: A total of 6,483 individuals aged between 13–18 y in the National Comorbidity Survey-Adolescent Supplement (NCS-A) with both individual and parental reports of mental health were included in this study. Participants were classified with insomnia symptoms if they reported difficulty initiating sleep, difficulty maintaining sleep, and/or early morning awakening, nearly every day for at least 2 w in the past year. Nearly one-third of adolescents reported insomnia symptoms for at least 2 w during the previous year. Hispanic and black youth were significantly more likely to report insomnia symptoms (42.0% and 41.3%, respectively) than non-Hispanic white youth (30.4%). Adolescents with insomnia symptoms were at a higher risk for all classes of mental disorders {odds ratio [OR] (95% confidence interval [CI]: 3.4 (2.9–4.0)} including mood, anxiety, behavioral, substance use, and eating disorders, suicidality [OR (95% CI): 2.63 (1.34–5.16)], poor perceived mental health [OR (95% CI): 2.01 (1.02–3.96)], chronic medical conditions [OR (95% CI): 1.94 (1.55–2.43)], smoking [OR (95% CI: 2.60 (1.00–6.72)], and obesity [OR (95% CI: 1.46 (1.10–1.93)] than those without insomnia symptoms. Adolescents with insomnia symptoms and comorbid mental disorders manifested even greater rates of these indicators of negative health behaviors and disorders than those with mental disorders alone (P Insomnia symptoms are reported by one-third of adolescents in the general population. Insomnia symptoms, even in the absence of concomitant depression or other mental disorders, are associated with serious health conditions, risk factors

  11. Random Sampling of Correlated Parameters – a Consistent Solution for Unfavourable Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Žerovnik, G., E-mail: gasper.zerovnik@ijs.si [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Trkov, A. [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); International Atomic Energy Agency, PO Box 100, A-1400 Vienna (Austria); Kodeli, I.A. [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Capote, R. [International Atomic Energy Agency, PO Box 100, A-1400 Vienna (Austria); Smith, D.L. [Argonne National Laboratory, 1710 Avenida del Mundo, Coronado, CA 92118-3073 (United States)

    2015-01-15

    Two methods for random sampling according to a multivariate lognormal distribution – the correlated sampling method and the method of transformation of correlation coefficients – are briefly presented. The methods are mathematically exact and enable consistent sampling of correlated inherently positive parameters with given information on the first two distribution moments. Furthermore, a weighted sampling method to accelerate the convergence of parameters with extremely large relative uncertainties is described. However, the method is efficient only for a limited number of correlated parameters.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-01

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

  13. Radial line-scans as representative sampling strategy in dried-droplet laser ablation of liquid samples deposited on pre-cut filter paper disks.

    Science.gov (United States)

    Nischkauer, Winfried; Vanhaecke, Frank; Bernacchi, Sébastien; Herwig, Christoph; Limbeck, Andreas

    2014-11-01

    Nebulising liquid samples and using the aerosol thus obtained for further analysis is the standard method in many current analytical techniques, also with inductively coupled plasma (ICP)-based devices. With such a set-up, quantification via external calibration is usually straightforward for samples with aqueous or close-to-aqueous matrix composition. However, there is a variety of more complex samples. Such samples can be found in medical, biological, technological and industrial contexts and can range from body fluids, like blood or urine, to fuel additives or fermentation broths. Specialized nebulizer systems or careful digestion and dilution are required to tackle such demanding sample matrices. One alternative approach is to convert the liquid into a dried solid and to use laser ablation for sample introduction. Up to now, this approach required the application of internal standards or matrix-adjusted calibration due to matrix effects. In this contribution, we show a way to circumvent these matrix effects while using simple external calibration for quantification. The principle of representative sampling that we propose uses radial line-scans across the dried residue. This compensates for centro-symmetric inhomogeneities typically observed in dried spots. The effectiveness of the proposed sampling strategy is exemplified via the determination of phosphorus in biochemical fermentation media. However, the universal viability of the presented measurement protocol is postulated. Detection limits using laser ablation-ICP-optical emission spectrometry were in the order of 40 μg mL - 1 with a reproducibility of 10 % relative standard deviation (n = 4, concentration = 10 times the quantification limit). The reported sensitivity is fit-for-purpose in the biochemical context described here, but could be improved using ICP-mass spectrometry, if future analytical tasks would require it. Trueness of the proposed method was investigated by cross-validation with

  14. Assessing the Risk Factors of Cyber and Mobile Phone Bullying Victimization in a Nationally Representative Sample of Singapore Youth.

    Science.gov (United States)

    Holt, Thomas J; Fitzgerald, Sarah; Bossler, Adam M; Chee, Grace; Ng, Esther

    2016-04-01

    This study utilized routine activity theory to examine the relationships between online behaviors, target suitability, and cyber and mobile phone-based bullying victimization in a nationally representative sample of youth from nine schools across Singapore. Key measures in all three categories-access to technology, online routine behaviors, and target suitability-were significant predictors of both forms of bullying victimization. In particular, females and victims of physical bullying were more likely to experience both forms of victimization. Access to technology and online routine behaviors predicted cyber and mobile phone-based bullying victimization differently. These findings demonstrate that routine activity theory is a viable framework to understand online bullying in non-Western nations, consistent with the existing literature on Western nations. © The Author(s) 2014.

  15. Application of morphological and physiological parameters representative of a Brazilian population sample in the respiratory tract model

    International Nuclear Information System (INIS)

    Dos Reis, A. A.; Cardoso, J. C. S.; Lourenco, M. C.

    2007-01-01

    The human respiratory tract model (HRTM) adopted by ICRP in its Publication 66 accounts for the morphology and physiology of the respiratory tract. The characteristics of air drawn into the lungs and exhaled are greatly influenced by the morphology of the respiratory tract, which causes numerous changes in pressure, flow rate, direction and humidity as air moves into and out of the lungs. These characteristics are important to determine the fractional deposition. It is known that the morphology and physiology are influenced by environmental, occupational and economic conditions. The ICRP recommends, for a reliable evaluation of the regional deposition, the use of parameters from a local population wherever such information is available. The main purpose of this study is to verify the influence of using the morphology and physiology parameters representative of a sample of the Brazilian population on the deposition model of the ICRP Publication 66 model. (authors)

  16. The influence of polycyclic aromatic hydrocarbons on lung function in a representative sample of the Canadian population.

    Science.gov (United States)

    Cakmak, Sabit; Hebbern, Chris; Cakmak, Jasmine D; Dales, Robert E

    2017-09-01

    We investigated the associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and selected respiratory physiologic measures in cycles 2 and 3 of the Canadian Health Measures Survey, a nationally representative population sample. Using generalized linear mixed models, we tested the association between selected PAH metabolites and 1-second forced expiratory volume (FEV 1 ), forced vital capacity (FVC), and the ratio between the two (FEV 1 /FVC) in 3531 people from 6 to 79 years of age. An interquartile change in urinary PAH metabolite was associated with significant decrements in FEV 1 and FVC for eight PAHs, 2-hydroxynapthalene, 1-, and 2-hydroxyphenanthrene, 2-, 3-, and 9-hydroxyfluorene and 3- and 4-hydroxyphenanthrene. Exposure to PAH may negatively affect lung function in the Canadian population. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  17. The longitudinal relation between peer violent victimization and delinquency: results from a national representative sample of u.s. Adolescents.

    Science.gov (United States)

    Jackson, Corrie L; Hanson, Rochelle F; Amstadter, Ananda B; Saunders, Benjamin E; Kilpatrick, Dean G

    2013-05-01

    Using a nationally representative sample of adolescents from the United States aged 12 to 17 years (Wave 1, n = 3,614; Wave 2, n = 2,511), this study examined (a) demographic and descriptive information about peer violent victimization (PVV); and (b) the longitudinal relation between a history of PVV and delinquency. Results indicated that 12.4% of adolescents reported lifetime exposure to PVV, and many of these adolescents with a previous history of PVV also reported exposure to other forms of interpersonal violence, with witnessing community/school violence being the most commonly endorsed exposure category. Males, older adolescents, African American adolescents, and adolescents from low-income households were significantly more likely to endorse PVV. Regardless of the victim's gender, the majority of the perpetrators were male. After controlling for exposure to other forms of interpersonal violence and a history of delinquency, PVV was related to subsequent delinquency. Implications for policy, practice, and future research are discussed.

  18. Child sexual abuse as a risk factor for teen dating violence: Findings from a representative sample of Quebec youth

    Science.gov (United States)

    Hébert, Martine; Moreau, Catherine; Blais, Martin; Lavoie, Francine; Guerrier, Mireille

    2016-01-01

    Child sexual abuse (CSA) is identified as a significant risk factor for later victimization in the context of adult intimate relationships, but less is known about the risk associated with CSA in early romantic relationships. This paper aims to document the association between CSA and teen dating victimization in a large representative sample of Quebec high-school students. As part of the Youths’ Romantic Relationships Project, 8,194 teens completed measures on CSA and psychological, physical and sexual dating violence. After controlling for other interpersonal traumas, results show that CSA contributed to all three forms of dating victimization among both boys and girls. The heightened risk of revictimization appears to be stronger for male victims of CSA. Intervention and prevention efforts are clearly needed to reduce the vulnerability of male and female victims of sexual abuse who are entering the crucial phase of adolescence and first romantic relationships. PMID:29308104

  19. Past-Year Treatment Utilization Among Individuals Meeting DSM-5 PTSD Criteria: Results From a Nationally Representative Sample.

    Science.gov (United States)

    Hale, Andrew C; Sripada, Rebecca K; Bohnert, Kipling M

    2018-03-01

    Little is known regarding treatment utilization among individuals meeting DSM-5 criteria for posttraumatic stress disorder (PTSD). Data were analyzed from the third wave of the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample using DSM-5 criteria. Factors related to increased odds of PTSD treatment utilization for individuals meeting lifetime criteria included some college education versus less than a high school degree (odds ratio [OR]=3.17), having health insurance versus no insurance (OR=2.86), having a comorbid phobia disorder versus not having a phobia disorder (OR=1.36), and greater PTSD symptom count (OR=1.11). Older age (OR=.40), identifying as black or Asian versus white non-Hispanic (OR=.70 and OR=.28, respectively), and greater social functioning (OR=.98) were associated with decreased odds of PTSD treatment utilization. Results highlight factors that may be useful in identifying population subgroups with PTSD that are at risk for underutilization of services.

  20. Attitudes toward Bisexual Men and Women among a Nationally Representative Probability Sample of Adults in the United States

    Science.gov (United States)

    Herbenick, Debby; Friedman, M. Reuel; Schick, Vanessa; Fu, Tsung-Chieh (Jane); Bostwick, Wendy; Bartelt, Elizabeth; Muñoz-Laboy, Miguel; Pletta, David; Reece, Michael; Sandfort, Theo G. M.

    2016-01-01

    As bisexual individuals in the United States (U.S.) face significant health disparities, researchers have posited that these differences may be fueled, at least in part, by negative attitudes, prejudice, stigma, and discrimination toward bisexual individuals from heterosexual and gay/lesbian individuals. Previous studies of individual and social attitudes toward bisexual men and women have been conducted almost exclusively with convenience samples, with limited generalizability to the broader U.S. population. Our study provides an assessment of attitudes toward bisexual men and women among a nationally representative probability sample of heterosexual, gay, lesbian, and other-identified adults in the U.S. Data were collected from the 2015 National Survey of Sexual Health and Behavior (NSSHB), via an online questionnaire with a probability sample of adults (18 years and over) from throughout the U.S. We included two modified 5-item versions of the Bisexualities: Indiana Attitudes Scale (BIAS), validated sub-scales that were developed to measure attitudes toward bisexual men and women. Data were analyzed using descriptive statistics, gamma regression, and paired t-tests. Gender, sexual identity, age, race/ethnicity, income, and educational attainment were all significantly associated with participants' attitudes toward bisexual individuals. In terms of responses to individual scale items, participants were most likely to “neither agree nor disagree” with all attitudinal statements. Across sexual identities, self-identified other participants reported the most positive attitudes, while heterosexual male participants reported the least positive attitudes. As in previous research on convenience samples, we found a wide range of demographic characteristics were related with attitudes toward bisexual individuals in our nationally-representative study of heterosexual, gay/lesbian, and other-identified adults in the U.S. In particular, gender emerged as a significant

  1. Attitudes toward Bisexual Men and Women among a Nationally Representative Probability Sample of Adults in the United States.

    Science.gov (United States)

    Dodge, Brian; Herbenick, Debby; Friedman, M Reuel; Schick, Vanessa; Fu, Tsung-Chieh Jane; Bostwick, Wendy; Bartelt, Elizabeth; Muñoz-Laboy, Miguel; Pletta, David; Reece, Michael; Sandfort, Theo G M

    2016-01-01

    As bisexual individuals in the United States (U.S.) face significant health disparities, researchers have posited that these differences may be fueled, at least in part, by negative attitudes, prejudice, stigma, and discrimination toward bisexual individuals from heterosexual and gay/lesbian individuals. Previous studies of individual and social attitudes toward bisexual men and women have been conducted almost exclusively with convenience samples, with limited generalizability to the broader U.S. Our study provides an assessment of attitudes toward bisexual men and women among a nationally representative probability sample of heterosexual, gay, lesbian, and other-identified adults in the U.S. Data were collected from the 2015 National Survey of Sexual Health and Behavior (NSSHB), via an online questionnaire with a probability sample of adults (18 years and over) from throughout the U.S. We included two modified 5-item versions of the Bisexualities: Indiana Attitudes Scale (BIAS), validated sub-scales that were developed to measure attitudes toward bisexual men and women. Data were analyzed using descriptive statistics, gamma regression, and paired t-tests. Gender, sexual identity, age, race/ethnicity, income, and educational attainment were all significantly associated with participants' attitudes toward bisexual individuals. In terms of responses to individual scale items, participants were most likely to "neither agree nor disagree" with all attitudinal statements. Across sexual identities, self-identified other participants reported the most positive attitudes, while heterosexual male participants reported the least positive attitudes. As in previous research on convenience samples, we found a wide range of demographic characteristics were related with attitudes toward bisexual individuals in our nationally-representative study of heterosexual, gay/lesbian, and other-identified adults in the U.S. In particular, gender emerged as a significant characteristic

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

    Science.gov (United States)

    Williamson, Graham R

    2003-11-01

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

  3. Creating a sampling frame for population-based veteran research: representativeness and overlap of VA and Department of Defense databases.

    Science.gov (United States)

    Washington, Donna L; Sun, Su; Canning, Mark

    2010-01-01

    Most veteran research is conducted in Department of Veterans Affairs (VA) healthcare settings, although most veterans obtain healthcare outside the VA. Our objective was to determine the adequacy and relative contributions of Veterans Health Administration (VHA), Veterans Benefits Administration (VBA), and Department of Defense (DOD) administrative databases for representing the U.S. veteran population, using as an example the creation of a sampling frame for the National Survey of Women Veterans. In 2008, we merged the VHA, VBA, and DOD databases. We identified the number of unique records both overall and from each database. The combined databases yielded 925,946 unique records, representing 51% of the 1,802,000 U.S. women veteran population. The DOD database included 30% of the population (with 8% overlap with other databases). The VHA enrollment database contributed an additional 20% unique women veterans (with 6% overlap with VBA databases). VBA databases contributed an additional 2% unique women veterans (beyond 10% overlap with other databases). Use of VBA and DOD databases substantially expands access to the population of veterans beyond those in VHA databases, regardless of VA use. Adoption of these additional databases would enhance the value and generalizability of a wide range of studies of both male and female veterans.

  4. Life course persistent and adolescence limited conduct disorder in a nationally representative US sample: prevalence, predictors, and outcomes.

    Science.gov (United States)

    Moore, Ashlee A; Silberg, Judy L; Roberson-Nay, Roxann; Mezuk, Briana

    2017-04-01

    The course of conduct disorder (CD) is heterogeneous. Moffitt proposed the heuristic of life course persistent (LCP) and adolescence limited (AL) to differentiate etiologically distinct forms of antisocial behavior (AB), each with distinct predictors and consequences, although a few studies have assessed this demarcation within the context of CD. The objective of this study was to apply Moffitt's taxonomy in a nationally representative US sample to investigate the prevalence, predictors, and outcomes of LCP and AL CD. Data come from the Collaborative Psychiatric Epidemiology Studies, a set of population-based nationally representative cross-sectional surveys (N = 20,130). Predictors included harsh discipline, maternal and paternal closeness, poverty in childhood, history of learning disability, parental deviance, and nativity. Outcomes included substance use, employment status, education attainment, marital status, income level, and self-rated mental and physical health. The prevalence of LCP and AL CD was 0.5 and 4.6%, respectively, for females, and 1.9 and 5.1%, respectively, for males. Low childhood SES [Odds Ratio (OR) = 3.49], lack of maternal closeness (OR = 2.50), and history of harsh discipline (OR = 2.17) increased odds of LCP group membership. The LCP group had higher odds of developing substance use disorders (OR = 2.00) relative to AL. LCP CD is more strongly influenced by childhood environment and confers increased odds for substance use problems in adulthood relative to AL CD.

  5. Ultra-processed food purchases in Norway: a quantitative study on a representative sample of food retailers.

    Science.gov (United States)

    Solberg, Siri Løvsjø; Terragni, Laura; Granheim, Sabrina Ionata

    2016-08-01

    To identify the use of ultra-processed foods - vectors of salt, sugar and fats - in the Norwegian diet through an assessment of food sales. Sales data from a representative sample of food retailers in Norway, collected in September 2005 (n 150) and September 2013 (n 170), were analysed. Data consisted of barcode scans of individual food item purchases, reporting type of food, price, geographical region and retail concept. Foods were categorized as minimally processed, culinary ingredients, processed products and ultra-processed. Indicators were share of purchases and share of expenditure on food categories. Six geographical regions in Norway. The barcode data included 296 121 observations in 2005 and 501 938 observations in 2013. Ultra-processed products represented 58·8 % of purchases and 48·8 % of expenditure in 2013. Minimally processed foods accounted for 17·2 % of purchases and 33·0 % of expenditure. Every third purchase was a sweet ultra-processed product. Food sales changed marginally in favour of minimally processed foods and in disfavour of processed products between 2005 and 2013 (χ 2 (3)=203 195, Pprocessed products accounted for the majority of food sales in Norway, indicating a high consumption of such products. This could be contributing to rising rates of overweight, obesity and non-communicable diseases in the country, as findings from other countries indicate. Policy measures should aim at decreasing consumption of ultra-processed products and facilitating access (including economic) to minimally processed foods.

  6. Prevalence of childhood sexual abuse and timing of disclosure in a representative sample of adults from Quebec.

    Science.gov (United States)

    Hébert, Martine; Tourigny, Marc; Cyr, Mireille; McDuff, Pierre; Joly, Jacques

    2009-09-01

    Our study sought to explore patterns of disclosure of child sexual abuse (CSA) in a sample of adult men and women. A telephone survey conducted with a representative sample of adults (n = 804) from Quebec assessed the prevalence of CSA and disclosure patterns. Analyses were carried out to determine whether disclosure groups differed in terms of psychological distress and symptoms of posttraumatic stress, and a logistic regression was used to examine factors associated with prompt disclosure. Prevalence of CSA was 22.1% for women and 9.7% for men. About 1 survivor out of 5 had never disclosed the abuse, with men more likely not to have told anyone, than women. Only 21.2% of adults reported prompt disclosure (within a month of the first abusive event), while 57.5% delayed disclosure (more than 5 years after the first episode). CSA victims who never disclosed the abuse and those who delayed disclosure were more likely to obtain scores of psychological distress and posttraumatic stress achieving clinical levels, compared with adults without a history of CSA. In the multivariate analysis, experiencing CSA involving a perpetrator outside the immediate family and being female were factors independently associated with prompt disclosure. A significant number of adult women and men reported experiencing CSA, and most victims attested to either not disclosing or significantly delaying abuse disclosure.

  7. Learning in later life: participation in formal, non-formal and informal activities in a nationally representative Spanish sample.

    Science.gov (United States)

    Villar, Feliciano; Celdrán, Montserrat

    2013-06-01

    This article examines the participation of Spanish older people in formal, non-formal and informal learning activities and presents a profile of participants in each kind of learning activity. We used data from a nationally representative sample of Spanish people between 60 and 75 years old ( n  = 4,703). The data were extracted from the 2007 Encuesta sobre la Participación de la Población Adulta en Actividades de Aprendizaje (EADA, Survey on Adult Population Involvement in Learning Activities). Overall, only 22.8 % of the sample participated in a learning activity. However, there was wide variation in the participation rates for the different types of activity. Informal activities were far more common than formal ones. Multivariate logistic regression indicated that education level and involvement in social and cultural activities were associated with likelihood of participating, regardless of the type of learning activity. When these variables were taken into account, age did not predict decreasing participation, at least in non-formal and informal activities. Implications for further research, future trends and policies to promote older adult education are discussed.

  8. Frequency of Aggressive Behaviors in a Nationally Representative Sample of Iranian Children and Adolescents: The CASPIAN-IV Study.

    Science.gov (United States)

    Sadinejad, Morteza; Bahreynian, Maryam; Motlagh, Mohammad-Esmaeil; Qorbani, Mostafa; Movahhed, Mohsen; Ardalan, Gelayol; Heshmat, Ramin; Kelishadi, Roya

    2015-01-01

    This study aims to explore the frequency of aggressive behaviors among a nationally representative sample of Iranian children and adolescents. This nationwide study was performed on a multi-stage sample of 6-18 years students, living in 30 provinces in Iran. Students were asked to confidentially report the frequency of aggressive behaviors including physical fighting, bullying and being bullied in the previous 12 months, using the questionnaire of the World Health Organization Global School Health Survey. In this cross-sectional study, 13,486 students completed the study (90.6% participation rate); they consisted of 49.2% girls and 75.6% urban residents. The mean age of participants was 12.47 years (95% confidence interval: 12.29, 12.65). In total, physical fight was more prevalent among boys than girls (48% vs. 31%, P bulling to other classmates had a higher frequency among boys compared to girls (29% vs. 25%, P bulling to others). Physical fighting was more prevalent among rural residents (40% vs. 39%, respectively, P = 0.61), while being bullied was more common among urban students (27% vs. 26%, respectively, P = 0.69). Although in this study the frequency of aggressive behaviors was lower than many other populations, still these findings emphasize on the importance of designing preventive interventions that target the students, especially in early adolescence, and to increase their awareness toward aggressive behaviors. Implications for future research and aggression prevention programming are recommended.

  9. Generating Random Samples of a Given Size Using Social Security Numbers.

    Science.gov (United States)

    Erickson, Richard C.; Brauchle, Paul E.

    1984-01-01

    The purposes of this article are (1) to present a method by which social security numbers may be used to draw cluster samples of a predetermined size and (2) to describe procedures used to validate this method of drawing random samples. (JOW)

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    PURPOSE: To analyze the distribution of depressive, anxiety, and somatization symptoms across different occupational positions in a random sample of Danish residents. METHODS: The study sample consisted of 591 Danish residents (50% women), aged 20-65, drawn from an age- and gender-stratified random...... sample of the Danish population. Participants filled out a survey that included the 92 item version of the Hopkins Symptom Checklist (SCL-92). We categorized occupational position into seven groups: high- and low-grade non-manual workers, skilled and unskilled manual workers, high- and low-grade self...

  11. Culturally appropriate methodology in obtaining a representative sample of South Australian Aboriginal adults for a cross-sectional population health study: challenges and resolutions.

    Science.gov (United States)

    Marin, Tania; Taylor, Anne Winifred; Grande, Eleonora Dal; Avery, Jodie; Tucker, Graeme; Morey, Kim

    2015-05-19

    The considerably lower average life expectancy of Aboriginal and Torres Strait Islander Australians, compared with non-Aboriginal and non-Torres Strait Islander Australians, has been widely reported. Prevalence data for chronic disease and health risk factors are needed to provide evidence based estimates for Australian Aboriginal and Torres Strait Islanders population health planning. Representative surveys for these populations are difficult due to complex methodology. The focus of this paper is to describe in detail the methodological challenges and resolutions of a representative South Australian Aboriginal population-based health survey. Using a stratified multi-stage sampling methodology based on the Australian Bureau of Statistics 2006 Census with culturally appropriate and epidemiological rigorous methods, 11,428 randomly selected dwellings were approached from a total of 209 census collection districts. All persons eligible for the survey identified as Aboriginal and/or Torres Strait Islander and were selected from dwellings identified as having one or more Aboriginal person(s) living there at the time of the survey. Overall, the 399 interviews from an eligible sample of 691 SA Aboriginal adults yielded a response rate of 57.7%. These face-to-face interviews were conducted by ten interviewers retained from a total of 27 trained Aboriginal interviewers. Challenges were found in three main areas: identification and recruitment of participants; interviewer recruitment and retainment; and using appropriate engagement with communities. These challenges were resolved, or at least mainly overcome, by following local protocols with communities and their representatives, and reaching agreement on the process of research for Aboriginal people. Obtaining a representative sample of Aboriginal participants in a culturally appropriate way was methodologically challenging and required high levels of commitment and resources. Adhering to these principles has resulted in a

  12. Psychometric properties and measurement invariance of the Beck hopelessness scale (BHS): results from a German representative population sample.

    Science.gov (United States)

    Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar

    2018-04-25

    The Beck Hopelessness Scale (BHS) has been the most frequently used instrument for the measurement of hopelessness in the past 40 years. Only recently has it officially been translated into German. The psychometric properties and factor structure of the BHS have been cause for intensive debate in the past. Based on a representative sample of the German population (N = 2450) item analysis including item sensitivity, item-total correlation and item difficulty was performed. Confirmatory factor analyses (CFA) for several factor solutions from the literature were performed. Multiple group factor analysis was performed to assess measurement invariance. Construct validity was assessed via the replication of well-established correlations with concurrently assessed measures. Most items exhibited adequate properties. Items #4, #8 and #13 exhibited poor item characteristics- each of these items had previously received negative evaluations in international studies. A one-dimensional factor solution, favorable for the calculation and interpretation of a sum score, was regarded as adequate. A bi-factor model with one content factor and two method factors (defined by positive/negative item coding) resulted in an excellent model fit. Cronbach's alpha in the current sample was .87. Hopelessness, as measured by the BHS, significantly correlated in the expected direction with suicidal ideation (r = .36), depression (r = .53) and life satisfaction (r = -.53). Strict measurement invariance could be established regarding gender and depression status. Due to limited research regarding the interpretation of fit indices with dichotomous data, interpretation of CFA results needs to remain tentative. The BHS is a valid measure of hopelessness in various subgroups of the general population. Future research could aim at replicating these findings using item response theory and cross-cultural samples. A one-dimensional bi-factor model seems appropriate even in a non

  13. The Association between Mental Health and Violence among a Nationally Representative Sample of College Students from the United States.

    Science.gov (United States)

    Schwartz, Joseph A; Beaver, Kevin M; Barnes, J C

    2015-01-01

    Recent violent attacks on college campuses in the United States have sparked discussions regarding the prevalence of psychiatric disorders and the perpetration of violence among college students. While previous studies have examined the potential association between mental health problems and violent behavior, the overall pattern of findings flowing from this literature remain mixed and no previous studies have examined such associations among college students. The current study makes use of a nationally representative sample of 3,929 college students from the National Epidemiologic Study on Alcohol and Related Conditions (NESARC) to examine the prevalence of seven violent behaviors and 19 psychiatric disorder diagnoses tapping mood, anxiety, personality, and substance use disorders. Associations between individual and composite psychiatric disorder diagnoses and violent behaviors were also examined. Additional analyses were adjusted for the comorbidity of multiple psychiatric diagnoses. The results revealed that college students were less likely to have engaged in violent behavior relative to the non-student sample, but a substantial portion of college students had engaged in violent behavior. Age- and sex-standardized prevalence rates indicated that more than 21% of college students reported at least one violent act. In addition, more than 36% of college students had at least one diagnosable psychiatric disorder. Finally, the prevalence of one or more psychiatric disorders significantly increased the odds of violent behavior within the college student sample. These findings indicate that violence and psychiatric disorders are prevalent on college campuses in the United States, though perhaps less so than in the general population. In addition, college students who have diagnosable psychiatric disorders are significantly more likely to engage in various forms of violent behavior.

  14. Prevalence of prehypertension and hypertension in a nationally representative sample of iranian children and adolescents: The CASPIAN-IV study

    Directory of Open Access Journals (Sweden)

    Zahra Fallah

    2014-01-01

    Full Text Available Background: The global health burden has faced toward non-communicable diseases (NCDs. It is suggested that adulthood blood pressure (BP is tracked from childhood. This study aims to evaluate the mean BP and the prevalence of prehypertension and hypertension in the Iranian pediatric population. Methods: In a national survey as the 4 th phase of Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable diseases study and through random multistage cluster sampling, a national sample of Iranian school students, aged 6-18 years, were recruited. Data gathered by means of modified World Health Organization Global school-based student health survey questionnaire, a weight disorders determinants questionnaire and anthropometric and BP measurements. Prehypertension (HTN was defined as BP equal or greater than 90 th age and sex specific percentile or ≥120/80 mmHg and HTN was defined as BP ≥95 th percentile. Results: A total of 13486 students entered the study (49.2% girls, 75.6% urban. Mean age of participants was 11.47 ΁ 3.36 years. A total rate of 4.17% (3.84-4.52 95% CI for high systolic BP (SBP, 4.33% (3.99-4.68 for high diastolic BP (DBP and 6.88% (6.45-7.32 for high SBP and/or DBP was depicted. Conclusions: The prevalence rate of high BP (pre-HTN together with HTN is substantially high in this population. It is needed to study the causative situations and implement relevant interventions.

  15. Prevalence and Predictors of Video Game Addiction: A Study Based on a National Representative Sample of Gamers.

    Science.gov (United States)

    Wittek, Charlotte Thoresen; Finserås, Turi Reiten; Pallesen, Ståle; Mentzoni, Rune Aune; Hanss, Daniel; Griffiths, Mark D; Molde, Helge

    Video gaming has become a popular leisure activity in many parts of the world, and an increasing number of empirical studies examine the small minority that appears to develop problems as a result of excessive gaming. This study investigated prevalence rates and predictors of video game addiction in a sample of gamers, randomly selected from the National Population Registry of Norway ( N  = 3389). Results showed there were 1.4 % addicted gamers, 7.3 % problem gamers, 3.9 % engaged gamers, and 87.4 % normal gamers. Gender (being male) and age group (being young) were positively associated with addicted-, problem-, and engaged gamers. Place of birth (Africa, Asia, South- and Middle America) were positively associated with addicted- and problem gamers. Video game addiction was negatively associated with conscientiousness and positively associated with neuroticism. Poor psychosomatic health was positively associated with problem- and engaged gaming. These factors provide insight into the field of video game addiction, and may help to provide guidance as to how individuals that are at risk of becoming addicted gamers can be identified.

  16. Organizational factors associated with work-related sleep problems in a nationally representative sample of Korean workers.

    Science.gov (United States)

    Park, Jae Bum; Nakata, Akinori; Swanson, Naomi G; Chun, Heekyoung

    2013-02-01

    The purpose of this study was to assess the association of organizational factors with work-related sleep problems (WRSP) among Korean workers. The data were derived from the First Korean Working Conditions Survey conducted in 2006 with a representative sample of the Korean working population (n = 10,039). The overall prevalence of WRSP was 5.1% (95% confidence interval (CI) 4.7-5.5). Those who experienced sexual harassment at work (adjusted odds ratio (aOR) 3.47: 95% CI 1.77-6.81), discrimination due to sex (aOR 2.44: 95% CI 1.36-4.36) or age (aOR 2.22: 95% CI 1.52-3.23), violence at work (aOR 1.98: 95% CI 1.06-3.68), threat of violence (aOR 1.96: 95% CI 1.05-3.66), poor work-life balance (aOR 1.78: 95% CI 1.44-2.20), low job satisfaction (aOR 1.69: 95% CI 1.37-2.09), high cognitive (OR 1.64: 95% CI 1.32-2.03) and emotional (aOR 1.53: 95% CI 1.22-1.91) demands, job insecurity (aOR 1.32: 95% CI 1.07-1.63), and high work intensity (aOR 1.55: 95% CI: 95% CI 1.25-1.92) had an increased risk of WRSP compared to their respective counterparts (p social support was not significantly associated with WRSP (aOR 0.88: 95% CI 0.67-1.15). The results revealed that poor psychosocial working conditions may be related to a high prevalence of WRSP among representative Korean workers.

  17. Prevalence and sociodemographic associations of common mental disorders in a nationally representative sample of the general population of Greece.

    Science.gov (United States)

    Skapinakis, Petros; Bellos, Stefanos; Koupidis, Sotirios; Grammatikopoulos, Ilias; Theodorakis, Pavlos N; Mavreas, Venetsanos

    2013-06-04

    No study in Greece has assessed so far the full range of common mental disorders using a representative sample of the population from both mainland and insular regions of the country. The aim of the present paper was to present the results of the first such study. The study was carried out between 2009-2010 in a nationally representative sample of 4894 individuals living in private households in Greece. Common mental disorders in the past week were assessed with the revised Clinical Interview Schedule (CIS-R). We also assessed alcohol use disorders (using AUDIT), smoking and cannabis use. 14% of the population (Male: 11%, Female: 17%) was found to have clinically significant psychiatric morbidity according to the scores on the CIS-R. The prevalence (past seven days) of specific common mental disorders was as follows: Generalized Anxiety Disorder: 4.10% (95% CI: 3.54, 4.65); Depression: 2.90% (2.43, 3.37); Panic Disorder: 1.88% (1.50, 2.26); Obsessive-Compulsive Disorder: 1.69% (1.33, 2.05); All Phobias: 2.79% (2.33, 3.26); Mixed anxiety-depression: 2.67% (2.22, 3.12). Harmful alcohol use was reported by 12.69% of the population (11.75, 13.62). Regular smoking was reported by 39.60% of the population (38.22, 40.97) while cannabis use (at least once during the past month) by 2.06% (1.66, 2.46). Clinically significant psychiatric morbidity was positively associated with the following variables: female gender, divorced or widowed family status, low educational status and unemployment. Use of all substances was more common in men compared to women. Common mental disorders were often comorbid, undertreated, and associated with a lower quality of life. The findings of the present study can help in the better planning and development of mental health services in Greece, especially in a time of mental health budget restrictions.

  18. Health correlates of insomnia symptoms and comorbid mental disorders in a nationally representative sample of US adolescents.

    Science.gov (United States)

    Blank, Madeleine; Zhang, Jihui; Lamers, Femke; Taylor, Adrienne D; Hickie, Ian B; Merikangas, Kathleen R

    2015-01-01

    To estimate the prevalence and health correlates of insomnia symptoms and their association with comorbid mental disorders in a nationally representative sample of adolescents in the United States. National representative cross-sectional study. Population-based sample from the US adolescents. A total of 6,483 individuals aged between 13–18 y in the National Comorbidity Survey-Adolescent Supplement (NCS-A) with both individual and parental reports of mental health were included in this study. Participants were classified with insomnia symptoms if they reported difficulty initiating sleep, difficulty maintaining sleep, and/or early morning awakening, nearly every day for at least 2 w in the past year. Nearly one-third of adolescents reported insomnia symptoms for at least 2 w during the previous year. Hispanic and black youth were significantly more likely to report insomnia symptoms (42.0% and 41.3%, respectively) than non-Hispanic white youth (30.4%). Adolescents with insomnia symptoms were at a higher risk for all classes of mental disorders {odds ratio [OR] (95% confidence interval [CI]: 3.4 (2.9–4.0)} including mood, anxiety, behavioral, substance use, and eating disorders, suicidality [OR (95% CI): 2.63 (1.34–5.16)], poor perceived mental health [OR (95% CI): 2.01 (1.02–3.96)], chronic medical conditions [OR (95% CI): 1.94 (1.55–2.43)], smoking [OR (95% CI: 2.60 (1.00–6.72)], and obesity [OR (95% CI: 1.46 (1.10–1.93)] than those without insomnia symptoms. Adolescents with insomnia symptoms and comorbid mental disorders manifested even greater rates of these indicators of negative health behaviors and disorders than those with mental disorders alone (P Insomnia symptoms are reported by one-third of adolescents in the general population. Insomnia symptoms, even in the absence of concomitant depression or other mental disorders, are associated with serious health conditions, risk factors, and suicidality. Comorbid mental disorders potentiate the

  19. Adverse childhood experiences predict earlier age of drinking onset: results from a representative US sample of current or former drinkers.

    Science.gov (United States)

    Rothman, Emily F; Edwards, Erika M; Heeren, Timothy; Hingson, Ralph W

    2008-08-01

    Our goal was to determine whether adverse childhood experiences predicted the age at which drinking was initiated and drinking motives in a representative sample of current or former drinkers in the United States. In 2006, a probability sample of 3592 US current or former drinkers aged 18 to 39 were surveyed. Multinomial logistic regression examined whether each of 10 adverse childhood experiences was associated with earlier ages of drinking onset, controlling for demographics, parental alcohol use, parental attitudes toward drinking, and peers' drinking in adolescence. We also examined whether there was a graded relationship between the number of adverse childhood experiences and age of drinking onset and whether adverse childhood experiences were related to self-reported motives for drinking during the first year that respondents drank. Sixty-six percent of respondents reported >or=1 adverse childhood experiences, and 19% reported experiencing >or=4. The most commonly reported adverse childhood experiences were parental separation/divorce (41.3%), living with a household member who was a problem drinker (28.7%), mental illness of a household member (24.8%), and sexual abuse (19.1%). Of the 10 specific adverse childhood experiences assessed, 5 were significantly associated with initiating drinking at or=21 years of age) after adjustment for confounders, including physical abuse, sexual abuse, having a mentally ill household member, substance abuse in the home, and parental discord or divorce. Compared with those without adverse childhood experiences, respondents with adverse childhood experiences were substantially more likely to report that they drank to cope during the first year that they used alcohol. Results suggest that children with particular adverse childhood experiences may initiate drinking earlier than their peers and that they may be more likely to drink to cope with problems (rather than for pleasure or to be social).

  20. Operationalization and Validation of the Stopping Elderly Accidents, Deaths, and Injuries (STEADI) Fall Risk Algorithm in a Nationally Representative Sample

    Science.gov (United States)

    Lohman, Matthew C.; Crow, Rebecca S.; DiMilia, Peter R.; Nicklett, Emily J.; Bruce, Martha L.; Batsis, John A.

    2017-01-01

    Background Preventing falls and fall-related injuries among older adults is a public health priority. The Stopping Elderly Accidents, Deaths, and Injuries (STEADI) tool was developed to promote fall risk screening and encourage coordination between clinical and community-based fall prevention resources; however, little is known about the tool’s predictive validity or adaptability to survey data. Methods Data from five annual rounds (2011–2015) of the National Health and Aging Trends Study (NHATS), a representative cohort of adults age 65 and older in the US. Analytic sample respondents (n=7,392) were categorized at baseline as having low, moderate, or high fall risk according to the STEADI algorithm adapted for use with NHATS data. Logistic mixed-effects regression was used to estimate the association between baseline fall risk and subsequent falls and mortality. Analyses incorporated complex sampling and weighting elements to permit inferences at a national level. Results Participants classified as having moderate and high fall risk had 2.62 (95% CI: 2.29, 2.99) and 4.76 (95% CI: 3.51, 6.47) times greater odds of falling during follow-up compared to those with low risk, respectively, controlling for sociodemographic and health related risk factors for falls. High fall risk was also associated with greater likelihood of falling multiple times annually but not with greater risk of mortality. Conclusion The adapted STEADI clinical fall risk screening tool is a valid measure for predicting future fall risk using survey cohort data. Further efforts to standardize screening for fall risk and to coordinate between clinical and community-based fall prevention initiatives are warranted. PMID:28947669

  1. Operationalisation and validation of the Stopping Elderly Accidents, Deaths, and Injuries (STEADI) fall risk algorithm in a nationally representative sample.

    Science.gov (United States)

    Lohman, Matthew C; Crow, Rebecca S; DiMilia, Peter R; Nicklett, Emily J; Bruce, Martha L; Batsis, John A

    2017-12-01

    Preventing falls and fall-related injuries among older adults is a public health priority. The Stopping Elderly Accidents, Deaths, and Injuries (STEADI) tool was developed to promote fall risk screening and encourage coordination between clinical and community-based fall prevention resources; however, little is known about the tool's predictive validity or adaptability to survey data. Data from five annual rounds (2011-2015) of the National Health and Aging Trends Study (NHATS), a representative cohort of adults age 65 years and older in the USA. Analytic sample respondents (n=7392) were categorised at baseline as having low, moderate or high fall risk according to the STEADI algorithm adapted for use with NHATS data. Logistic mixed-effects regression was used to estimate the association between baseline fall risk and subsequent falls and mortality. Analyses incorporated complex sampling and weighting elements to permit inferences at a national level. Participants classified as having moderate and high fall risk had 2.62 (95% CI 2.29 to 2.99) and 4.76 (95% CI 3.51 to 6.47) times greater odds of falling during follow-up compared with those with low risk, respectively, controlling for sociodemographic and health-related risk factors for falls. High fall risk was also associated with greater likelihood of falling multiple times annually but not with greater risk of mortality. The adapted STEADI clinical fall risk screening tool is a valid measure for predicting future fall risk using survey cohort data. Further efforts to standardise screening for fall risk and to coordinate between clinical and community-based fall prevention initiatives are warranted. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. Negative associations between corpus callosum midsagittal area and IQ in a representative sample of healthy children and adolescents.

    Directory of Open Access Journals (Sweden)

    Hooman Ganjavi

    Full Text Available Documented associations between corpus callosum size and cognitive ability have heretofore been inconsistent potentially owing to differences in sample characteristics, differing methodologies in measuring CC size, or the use of absolute versus relative measures. We investigated the relationship between CC size and intelligence quotient (IQ in the NIH MRI Study of Normal Brain Development sample, a large cohort of healthy children and adolescents (aged six to 18, n = 198 recruited to be representative of the US population. CC midsagittal area was measured using an automated system that partitioned the CC into 25 subregions. IQ was measured using the Wechsler Abbreviated Scale of Intelligence (WASI. After correcting for total brain volume and age, a significant negative correlation was found between total CC midsagittal area and IQ (r = -0.147; p = 0.040. Post hoc analyses revealed a significant negative correlation in children (age<12 (r = -0.279; p = 0.004 but not in adolescents (age≥12 (r = -0.005; p = 0.962. Partitioning the subjects by gender revealed a negative correlation in males (r = -0.231; p = 0.034 but not in females (r = 0.083; p = 0.389. Results suggest that the association between CC and intelligence is mostly driven by male children. In children, a significant gender difference was observed for FSIQ and PIQ, and in males, a significant age-group difference was observed for FSIQ and PIQ. These findings suggest that the correlation between CC midsagittal area and IQ may be related to age and gender.

  3. Investigating the factorial structure and availability of work time control in a representative sample of the Swedish working population.

    Science.gov (United States)

    Albrecht, Sophie C; Kecklund, Göran; Tucker, Philip; Leineweber, Constanze

    2016-05-01

    Past research has often neglected the sub-dimensions of work time control (WTC). Moreover, differences in levels of WTC with respect to work and demographic characteristics have not yet been examined in a representative sample. We investigated these matters in a recent sample of the Swedish working population. The study was based on the 2014 data collection of the Swedish Longitudinal Occupational Survey of Health. We assessed the structure of the WTC measure using exploratory and confirmatory factor analysis. Differences in WTC by work and demographic characteristics were examined with independent samplet-tests, one-way ANOVAs and gender-stratified logistic regressions. Best model fit was found for a two-factor structure that distinguished between control over daily hours and control over time off (root mean square error of approximation = 0.06; 95% CI 0.04 to 0.09; Comparative Fit Index (CFI) = 0.99). Women, shift and public-sector workers reported lower control in relation to both factors. Age showed small associations with WTC, while a stronger link was suggested for civil status and family situation. Night, roster and rotating shift work seemed to be the most influential factors on reporting low control over daily hours and time off. Our data confirm the two-dimensional structure underlying WTC, namely the components 'control over daily hours' and 'control over time off'. Women, public-sector and shift workers reported lower levels of control. Future research should examine the public health implications of WTC, in particular whether increased control over daily hours and time off can reduce health problems associated with difficult working-time arrangements. © 2015 the Nordic Societies of Public Health.

  4. Sex in Australia: autoerotic, esoteric and other sexual practices engaged in by a representative sample of adults.

    Science.gov (United States)

    Richters, Juliet; Grulich, Andrew E; de Visser, Richard O; Smith, Anthony M A; Rissel, Chris E

    2003-01-01

    To describe the prevalence of a range of autoerotic and other non-coital sexual practices among Australians. Computer-assisted telephone interviews were completed by a representative sample of 10,173 men and 9,134 women aged 16-59 years (response rate 73.1%). Respondents were asked whether in the past year they had: masturbated, engaged in various other autoerotic activities, or engaged in any of six other non-coital or esoteric practices. Half of the respondents (65% men, 35% women) had masturbated in the past year. Nearly half (48%) of the men and 25% of the women had masturbated in the past four weeks, among whom men had done so a mean of 5.8 times and women 3.3 times. About a quarter of all respondents had watched an X-rated film (37% men, 16% women), 12% of men and 14% of women had used a sex toy, and 17% of men and 2% of women had visited an Internet sex site. 17% of men and 14% of women had engaged in digital-anal stimulation with a partner. Phone sex, role play or dressing up, bondage and discipline, sadomasochism or dominance and submission (BDSM-DS), fisting (rectal or vaginal, insertive or receptive) and rimming (oral-anal stimulation) were all engaged in by less than 5% of the sample. Most of the practices studied were engaged in by more men than women. A range of autoerotic activities are both substitutes for partnered sex and additional sources of pleasure for people with sexual partners.

  5. Frequency of aggressive behaviors in a nationally representative sample of Iranian children and adolescents: The CASPIAN-IV study

    Directory of Open Access Journals (Sweden)

    Morteza Sadinejad

    2015-01-01

    Full Text Available Background: This study aims to explore the frequency of aggressive behaviors among a nationally representative sample of Iranian children and adolescents. Methods: This nationwide study was performed on a multi-stage sample of 6-18 years students, living in 30 provinces in Iran. Students were asked to confidentially report the frequency of aggressive behaviors including physical fighting, bullying and being bullied in the previous 12 months, using the questionnaire of the World Health Organization Global School Health Survey. Results: In this cross-sectional study, 13,486 students completed the study (90.6% participation rate; they consisted of 49.2% girls and 75.6% urban residents. The mean age of participants was 12.47 years (95% confidence interval: 12.29, 12.65. In total, physical fight was more prevalent among boys than girls (48% vs. 31%, P < 0.001. Higher rates of involvement in two other behaviors namely being bullied and bulling to other classmates had a higher frequency among boys compared to girls (29% vs. 25%, P < 0.001 for being bullied and (20% vs. 14%, P < 0.001 for bulling to others. Physical fighting was more prevalent among rural residents (40% vs. 39%, respectively, P = 0.61, while being bullied was more common among urban students (27% vs. 26%, respectively, P = 0.69. Conclusions: Although in this study the frequency of aggressive behaviors was lower than many other populations, still these findings emphasize on the importance of designing preventive interventions that target the students, especially in early adolescence, and to increase their awareness toward aggressive behaviors. Implications for future research and aggression prevention programming are recommended.

  6. Assessing childhood maltreatment and mental health correlates of disordered eating profiles in a nationally representative sample of English females.

    Science.gov (United States)

    Armour, Cherie; Műllerová, Jana; Fletcher, Shelley; Lagdon, Susan; Burns, Carol Rhonda; Robinson, Martin; Robinson, Jake

    2016-03-01

    Previous research suggests that childhood maltreatment is associated with the onset of eating disorders (ED). In turn, EDs are associated with alternative psychopathologies such as depression and posttraumatic stress disorder (PTSD), and with suicidality. Moreover, it has been reported that various ED profiles may exist. The aim of the current study was to examine the profiles of disordered eating and the associations of these with childhood maltreatment and with mental health psychopathology. The current study utilised a representative sample of English females (N = 4206) and assessed for the presence of disordered eating profiles using Latent Class Analysis. Multinomial logistic regression was implemented to examine the associations of childhood sexual and physical abuse with the disordered eating profiles and the associations of these with PTSD, depression and suicidality. Results supported those of previous findings in that we found five latent classes of which three were regarded as disordered eating classes. Significant relationships were found between these and measures of childhood trauma and mental health outcomes. Childhood sexual and physical abuse increased the likelihood of membership in disordered eating classes and these in turn increased the likelihood of adverse mental health and suicidal outcomes.

  7. Parent-Child Connectedness and Long-Term Risk for Suicidal Ideation in a Nationally Representative Sample of US Adolescents.

    Science.gov (United States)

    Kuramoto-Crawford, S Janet; Ali, Mir M; Wilcox, Holly C

    2017-09-01

    Few studies have addressed on the role of parent-child connectedness (PCC) on adolescents' risk for suicidal ideation from a longitudinal, developmental perspective. This study examined PCC during adolescence and risk of suicidal ideation into adulthood among a nationally representative sample of American adolescents. The study includes 13,234 adolescents aged 11-18 from the National Longitudinal Study of Adolescent to Adult Health (Add Health) who were surveyed during adolescence (1994-1995) and then again in early adulthood (2008-2009). Multinomial logistic regression estimated the association between PCC during adolescence and having ideation during the adolescence period only, in adulthood only, and in both adolescence and adulthood as compared with those without suicidal ideation. After adjusting for depressive symptoms and other parent and adolescent characteristics, adolescents in two-parent households who reported higher PCC during adolescence had lower relative risk of having ideation during adolescence alone and in both adolescence and adulthood. In mother-only households, higher mother connectedness was also associated with decreased risk of having adolescent ideation. PCC is an important modifiable target for the prevention of suicidal ideation from adolescence into adulthood.

  8. Eating style, overeating and weight gain. A prospective 2-year follow-up study in a representative Dutch sample.

    Science.gov (United States)

    van Strien, Tatjana; Herman, C Peter; Verheijden, Marieke W

    2012-12-01

    This study examined which individuals are particularly at risk for developing overweight and whether there are behavioral lifestyle factors that may attenuate this susceptibility. A prospective study with a 2-year follow-up was conducted in a sample representative of the general population of The Netherlands (n=590). Body mass change (self-reported) was assessed in relation to overeating and change in physical activity (both self-reported), dietary restraint, emotional eating, and external eating, as assessed by the Dutch Eating Behavior Questionnaire. There was a consistent main (suppressive) effect of increased physical activity on BMI change. Only emotional eating and external eating moderated the relation between overeating and body mass change. However, the interaction effect of external eating became borderline significant with Yes or No meaningful weight gain (weight gain >3%) as dependent variable. It was concluded that whilst increasing physical activity may attenuate weight gain, particularly high emotional eaters seem at risk for developing overweight, because overconsumption seems to be more strongly related to weight gain in people with high degrees of emotional eating. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Representativeness of soil samples collected to assess mining-related contamination of flood plains in southeast Kansas

    Science.gov (United States)

    Juracek, Kyle E.

    2015-01-01

    Historical lead and zinc mining in the Tri-State Mining District (TSMD), located in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma, has resulted in a substantial ongoing input of lead and zinc to the environment (Juracek, 2006; Juracek and Becker, 2009). In response to concern about the mining-related contamination, southeast Cherokee County, Kansas, was listed on the U.S. Environmental Protection Agency’s (USEPA) National Priority List as a Superfund hazardous waste site (fig. 1). To provide some of the information needed to support remediation efforts in the Cherokee County Superfund site, a study was begun in 2009 by the U.S. Geological Survey (USGS) that was requested and funded by USEPA. As part of the study, surficial-soil sampling was used to investigate the extent and magnitude of mining-related lead and zinc contamination in the flood plains of the Spring River and several tributaries within the Superfund site. In mining-affected areas, flood-plain soils had lead and zinc concentrations that far exceeded background levels as well as probable-effects guidelines for toxic aquatic biological effects (Juracek, 2013). Lead- and zinc-contaminated flood plains are a concern, in part, because they represent a long-term source of contamination to the fluvial environment.

  10. Age, sex, and racial differences in harsh physical punishment: results from a nationally representative United States sample.

    Science.gov (United States)

    Taillieu, Tamara L; Afifi, Tracie O; Mota, Natalie; Keyes, Katherine M; Sareen, Jitender

    2014-12-01

    The purpose of this research was to examine age, sex, and racial differences in the prevalence of harsh physical punishment in childhood in a nationally representative sample of the United States. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) collected in 2004 and 2005 (n=34,653). Logistic regression analyses were conducted to examine age, sex, and racial differences in the prevalence of harsh physical punishment. Results suggest that the prevalence of harsh physical punishment has been decreasing among more recently born age groups; however, there appear to be sex and racial differences in this trend over time. The magnitude of the decrease appears to be stronger for males than for females. By race, the decrease in harsh physical punishment over time is only apparent among Whites; Black participants demonstrate little change over time, and harsh physical punishment seems to be increasing over time among Hispanics. Prevention and intervention efforts that educate about the links of physical punishment to negative outcomes and alternative non-physical discipline strategies may be particularly useful in reducing the prevalence of harsh physical punishment over time. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Out-of-Pocket Expenditures on Complementary Health Approaches Associated with Painful Health Conditions in a Nationally Representative Adult Sample

    Science.gov (United States)

    Nahin, Richard L.; Stussman, Barbara J.; Herman, Patricia M.

    2015-01-01

    National surveys suggest that millions of adults in the United States use complementary health approaches such as acupuncture, chiropractic manipulation, and herbal medicines to manage painful conditions such as arthritis, back pain and fibromyalgia. Yet, national and per person out-of-pocket (OOP) costs attributable to this condition-specific use are unknown. In the 2007 National Health Interview Survey, use of complementary health approaches, reasons for this use, and associated OOP costs were captured in a nationally representative sample of 5,467 adults. Ordinary least square regression models that controlled for co-morbid conditions were used to estimate aggregate and per person OOP costs associated with 14 painful health conditions. Individuals using complementary approaches spent a total of $14.9 billion (S.E. $0.9 billion) OOP on these approaches to manage these painful conditions. Total OOP expenditures seen in those using complementary approaches for their back pain ($8.7 billion, S.E. $0.8 billion) far outstripped that of any other condition, with the majority of these costs ($4.7 billion, S.E. $0.4 billion) resulting from visits to complementary providers. Annual condition-specific per-person OOP costs varied from a low of $568 (SE $144) for regular headaches, to a high of $895 (SE $163) for fibromyalgia. PMID:26320946

  12. High burden of homelessness among sexual-minority adolescents: findings from a representative Massachusetts high school sample.

    Science.gov (United States)

    Corliss, Heather L; Goodenow, Carol S; Nichols, Lauren; Austin, S Bryn

    2011-09-01

    We compared the prevalence of current homelessness among adolescents reporting a minority sexual orientation (lesbian/gay, bisexual, unsure, or heterosexual with same-sex sexual partners) with that among exclusively heterosexual adolescents. We combined data from the 2005 and 2007 Massachusetts Youth Risk Behavior Survey, a representative sample of public school students in grades 9 though 12 (n = 6317). Approximately 25% of lesbian/gay, 15% of bisexual, and 3% of exclusively heterosexual Massachusetts public high school students were homeless. Sexual-minority males and females had an odds of reporting current homelessness that was between 4 and 13 times that of their exclusively heterosexual peers. Sexual-minority youths' greater likelihood of being homeless was driven by their increased risk of living separately from their parents or guardians. Youth homelessness is linked with numerous threats such as violence, substance use, and mental health problems. Although discrimination and victimization related to minority sexual orientation status are believed to be important causal factors, research is needed to improve our understanding of the risks and protective factors for homelessness and to determine effective strategies to prevent homelessness in this population.

  13. Problematic internet use and problematic online gaming are not the same: findings from a large nationally representative adolescent sample.

    Science.gov (United States)

    Király, Orsolya; Griffiths, Mark D; Urbán, Róbert; Farkas, Judit; Kökönyei, Gyöngyi; Elekes, Zsuzsanna; Tamás, Domokos; Demetrovics, Zsolt

    2014-12-01

    There is an ongoing debate in the literature whether problematic Internet use (PIU) and problematic online gaming (POG) are two distinct conceptual and nosological entities or whether they are the same. The present study contributes to this question by examining the interrelationship and the overlap between PIU and POG in terms of sex, school achievement, time spent using the Internet and/or online gaming, psychological well-being, and preferred online activities. Questionnaires assessing these variables were administered to a nationally representative sample of adolescent gamers (N=2,073; Mage=16.4 years, SD=0.87; 68.4% male). Data showed that Internet use was a common activity among adolescents, while online gaming was engaged in by a considerably smaller group. Similarly, more adolescents met the criteria for PIU than for POG, and a small group of adolescents showed symptoms of both problem behaviors. The most notable difference between the two problem behaviors was in terms of sex. POG was much more strongly associated with being male. Self-esteem had low effect sizes on both behaviors, while depressive symptoms were associated with both PIU and POG, affecting PIU slightly more. In terms of preferred online activities, PIU was positively associated with online gaming, online chatting, and social networking, while POG was only associated with online gaming. Based on our findings, POG appears to be a conceptually different behavior from PIU, and therefore the data support the notion that Internet Addiction Disorder and Internet Gaming Disorder are separate nosological entities.

  14. Educational Attainment by Life Course Sexual Attraction: Prevalence and Correlates in a Nationally Representative Sample of Young Adults

    Science.gov (United States)

    Walsemann, Katrina M.; Lindley, Lisa L.; Gentile, Danielle; Welihindha, Shehan V.

    2014-01-01

    Researchers know relatively little about the educational attainment of sexual minorities, despite the fact that educational attainment is consistently associated with a range of social, economic, and health outcomes. We examined whether sexual attraction in adolescence and early adulthood was associated with educational attainment in early adulthood among a nationally representative sample of US young adults. We analyzed Waves I and IV restricted data from the National Longitudinal Study of Adolescent Health (n=14,111). Sexual orientation was assessed using self-reports of romantic attraction in Waves I (adolescence) and IV (adulthood). Multinomial regression models were estimated and all analyses were stratified by gender. Women attracted to the same-sex in adulthood only had lower educational attainment compared to women attracted only to the opposite-sex in adolescence and adulthood. Men attracted to the same-sex in adolescence only had lower educational attainment compared to men attracted only to the opposite-sex in adolescence and adulthood. Adolescent experiences and academic performance attenuated educational disparities among men and women. Adjustment for adolescent experiences also revealed a suppression effect; women attracted to the same-sex in adolescence and adulthood had lower predicted probabilities of having a high school diploma or less compared to women attracted only to the opposite-sex in adolescence and adulthood. Our findings challenge previous research documenting higher educational attainment among sexual minorities in the US. Additional population-based studies documenting the educational attainment of sexual minority adults are needed. PMID:25382888

  15. Dietary intake patterns and diet quality in a nationally representative sample of women with and without severe headache or migraine.

    Science.gov (United States)

    Evans, E Whitney; Lipton, Richard B; Peterlin, B Lee; Raynor, Hollie A; Thomas, J Graham; O'Leary, Kevin C; Pavlovic, Jelena; Wing, Rena R; Bond, Dale S

    2015-04-01

    The role of diet in migraine is not well understood. We sought to characterize usual dietary intake patterns and diet quality in a nationally representative sample of women with and without severe headache or migraine. We also examined whether the relationship between migraine and diet differs by weight status. In this analysis, women with migraine or severe headache status was determined by questionnaire for 3069 women, ages 20-50 years, who participated in the National Health and Nutrition Examination Study, 1999-2004. Women who experienced severe headaches or migraines were classified as migraine for the purposes of this analysis. Dietary intake patterns (micro- and macronutrient intake and eating frequency) and diet quality, measured by the Healthy Eating Index, 2005, were determined using one 24-hour dietary recall. Dietary intake patterns did not significantly differ between women with and without migraine. Normal weight women with migraine had significantly lower diet quality (Healthy Eating Index, 2005 total scores) than women without migraine (52.5 ± 0.9 vs. 45.9 ± 1.0; P quality differs by migraine status in normal weight women. Prospective analyses are needed to establish how diet relates to migraine onset, characteristics, and clinical features in individuals of varying weight status. © 2015 American Headache Society.

  16. Gender differences in the associations of gambling activities and suicidal behaviors with problem gambling in a nationally representative French sample.

    Science.gov (United States)

    Husky, Mathilde M; Michel, Grégory; Richard, Jean-Baptiste; Guignard, Romain; Beck, François

    2015-06-01

    The objectives of the present study are to describe gender differences in factors associated with moderate risk and problem gambling. Data were extracted from the 2010 Health Barometer, a large survey on a representative sample of the general population aged 15-85 years living in France (n=27,653), carried out by the National Institute for Health Promotion and Health Education. Data were collected between October 2009 and July 2010. A computer-assisted telephone interview system was used. The findings indicate that men are three times more likely to experience problems with gambling. Men and women have different patterns of gambling activities. Men were more involved with Rapido, internet gambling, sports and racetrack betting, poker, and casino tables, whereas women gambled more often on scratch games. Both men and women engaging in immediate reward games were significantly more likely to experience difficulties with gambling. This association, however, was stronger in women. Furthermore, suicidal ideation and behaviors were more likely to be associated with gambling problems in women as compared to men. The study underscores the importance of considering gender-related differences in the study of gambling behaviors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Experimental study and modelling of the well-mixing length. Application to the representativeness of sampling points in duct

    International Nuclear Information System (INIS)

    Alengry, Jonathan

    2014-01-01

    Monitoring of gaseous releases from nuclear installations in the environment and air cleaning efficiency measurement are based on regular measurements of concentrations of contaminants in outlet chimneys and ventilation systems. The concentration distribution may be heterogeneous at the measuring point if the distance setting of the mixing is not sufficient. The question is about the set up of the measuring point in duct and the error compared to the homogeneous concentration in case of non-compliance with this distance. This study defines the so-called 'well mixing length' from laboratory experiments. The bench designed for these tests allowed to reproduce flows in long circular and rectangular ducts, each including a bend. An optical measurement technique has been developed, calibrated and used to measure the concentration distribution of a tracer injected in the flow. The experimental results in cylindrical duct have validated an analytical model based on the convection-diffusion equation of a tracer, and allowed to propose models of good mixing length and representativeness of sampling points. In rectangular duct, the acquired measures constitute a first database on the evolution of the homogenization of a tracer, in the perspective of numerical simulations exploring more realistic conditions for measurements in situ. (author) [fr

  18. The relationship between nonstandard working and mental health in a representative sample of the South Korean population.

    Science.gov (United States)

    Kim, Il-Ho; Muntaner, Carles; Khang, Young-Ho; Paek, Domyung; Cho, Sung-Il

    2006-08-01

    In light of escalating job insecurity due to increasing numbers of nonstandard workers, this study examined the association between nonstandard employment and mental health among South Korean workers. We analyzed a representative weighted sample of 2086 men and 1194 women aged 20-64 years, using data from the 1998 Korean National Health and Nutrition Examination Survey. Nonstandard employment included part-time work, temporary work, and daily work. Mental health was measured with indicators of self-reported depression and suicidal ideation. Based on age-adjusted prevalence of mental health, nonstandard employees were more likely to be mentally ill compared to standard employees. Furthermore, nonstandard work status was associated with poor mental health after adjusting for socioeconomic position (education, occupational class, and income) and health behaviors (smoking, alcohol consumption, and exercise). However, the pattern of the relationship between nonstandard work and mental health differed by gender. Female gender was significantly associated with poor mental health. Although males tended to report more suicidal ideation, this difference was not statistically significant. Considering the increasing prevalence of nonstandard working conditions in South Korea, the results call for more longitudinal research on the mental health effects of nonstandard work.

  19. Psychosocial and other working conditions in relation to body mass index in a representative sample of Australian workers

    Directory of Open Access Journals (Sweden)

    Louie Amber M

    2006-03-01

    Full Text Available Abstract Background The aim of the study was to examine the relationship between psychosocial and other working conditions and body-mass index (BMI in a working population. This study contributes to the approximately dozen investigations of job stress, which have demonstrated mixed positive and negative results in relation to obesity, overweight and BMI. Methods A cross-sectional population-based survey was conducted among working Australians in the state of Victoria. Participants were contacted by telephone from a random sample of phone book listings. Information on body mass index was self-reported as were psychosocial work conditions assessed using the demand/control and effort/reward imbalance models. Other working conditions measured included working hours, shift work, and physical demand. Separate linear regression analyses were undertaken for males and females, with adjustment for potential confounders. Results A total of 1101 interviews (526 men and 575 women were completed. Multivariate models (adjusted for socio-demographics demonstrated no associations between job strain, as measured using the demand/control model, or ERI using the effort/reward imbalance model (after further adjustment for over commitment and BMI among men and women. Multivariate models demonstrated a negative association between low reward and BMI among women. Among men, multivariate models demonstrated positive associations between high effort, high psychological demand, long working hours and BMI and a negative association between high physical demand and BMI. After controlling for the effort/reward imbalance or the demand/control model, the association between physical demand and working longer hours and BMI remained. Conclusion Among men and women the were differing patterns of both exposures to psychosocial working conditions and associations with BMI. Among men, working long hours was positively associated with higher BMI and this association was partly

  20. Random sampling of quantum states: a survey of methods and some issues regarding the Overparametrized Method

    International Nuclear Information System (INIS)

    Maziero, Jonas

    2015-01-01

    The numerical generation of random quantum states (RQS) is an important procedure for investigations in quantum information science. Here, we review some methods that may be used for performing that task. We start by presenting a simple procedure for generating random state vectors, for which the main tool is the random sampling of unbiased discrete probability distributions (DPD). Afterwards, the creation of random density matrices is addressed. In this context, we first present the standard method, which consists in using the spectral decomposition of a quantum state for getting RQS from random DPDs and random unitary matrices. In the sequence, the Bloch vector parametrization method is described. This approach, despite being useful in several instances, is not in general convenient for RQS generation. In the last part of the article, we regard the overparametrized method (OPM) and the related Ginibre and Bures techniques. The OPM can be used to create random positive semidefinite matrices with unit trace from randomly produced general complex matrices in a simple way that is friendly for numerical implementations. We consider a physically relevant issue related to the possible domains that may be used for the real and imaginary parts of the elements of such general complex matrices. Subsequently, a too fast concentration of measure in the quantum state space that appears in this parametrization is noticed. (author)

  1. Association of Some Vitamins and Minerals with Periodontitis in a Nationally Representative Sample of Korean Young Adults.

    Science.gov (United States)

    Park, Ji-A; Lee, Jung-Hwa; Lee, Hyo-Jin; Jin, Bo-Hyoung; Bae, Kwang-Hak

    2017-08-01

    The purpose of this study was to investigate whether the intakes of some kinds of vitamins and minerals are associated with periodontitis in a nationally representative sample of young adults. This study comprised 2049 young adults aged 19-39 years who took both periodontal examination and nutrition survey. The vitamin and mineral intakes were calculated from dietary intake data gained by complete one-day 24-h recall interviews, and the intake levels for each nutrient were classified by the Recommended Nutrient Intake (RNI) in Dietary Reference Intakes for Koreans and median values. Periodontitis was assessed using Community Periodontal Index (CPI). Multivariate logistic regression analyses were performed in a whole sample and subgroups with the strata of gender or smoking, following a complex sampling design. In analyses according to RNI, a lower intake of niacin was significantly associated with periodontitis in young adults (odd ratio [OR] 1.47, 95% confidential interval [CI] 1.09-2.00) and in its subgroup of women (OR 1.70; 95% CI 1.10-2.64) and current non-smokers (OR 1.75; 95% CI 1.22-2.51). Whereas, in analyses according to median intake values, there were significant associations of periodontitis with a lower intake of niacin in women (OR 1.58; 95% CI 1.02-2.46) and current non-smokers (OR 1.50; 95% CI 1.01-2.22), with lower intake of vitamin C in women (OR 1.66; 95% CI 1.04-2.64) and in current non-smokers (OR 1.49; 95% CI 1.04-2.14), with lower intake of iron in women (OR 1.85; 95% CI 1.11-3.07), and with lower intake of vitamin A marginally in women (OR 1.56; 95% CI 1.00-2.44). In young adults, periodonitis is significantly associated with the lower intakes of niacin, vitamin C, and iron, especially in women and current non-smokers.

  2. Trends of VOC exposures among a nationally representative sample: Analysis of the NHANES 1988 through 2004 data sets

    Science.gov (United States)

    Su, Feng-Chiao; Mukherjee, Bhramar; Batterman, Stuart

    2011-09-01

    Exposures to volatile organic compounds (VOCs) are ubiquitous due to emissions from personal, commercial and industrial products, but quantitative and representative information regarding long term exposure trends is lacking. This study characterizes trends from 1988 to 2004 for the 15 VOCs measured in blood in five cohorts of the National Health and Nutrition Examination Survey (NHANES), a large and representative sample of U.S. adults. Trends were evaluated at various percentiles using linear quantile regression (QR) models, which were adjusted for solvent-related occupations and cotinine levels. Most VOCs showed decreasing trends at all quantiles, e.g., median exposures declined by 2.5 (m,p-xylene) to 6.4 (tetrachloroethene) percent per year over the 15 year period. Trends varied by VOC and quantile, and were grouped into three patterns: similar decreases at all quantiles (including benzene, toluene); most rapid decreases at upper quantiles (ethylbenzene, m,p-xylene, o-xylene, styrene, chloroform, tetrachloroethene); and fastest declines at central quantiles (1,4-dichlorobenzene). These patterns reflect changes in exposure sources, e.g., upper-percentile exposures may result mostly from occupational exposure, while lower percentile exposures arise from general environmental sources. Both VOC emissions aggregated at the national level and VOC concentrations measured in ambient air also have declined substantially over the study period and are supportive of the exposure trends, although the NHANES data suggest the importance of indoor sources and personal activities on VOC exposures. While piecewise QR models suggest that exposures of several VOCs decreased little or any during the 1990's, followed by more rapid decreases from 1999 to 2004, questions are raised concerning the reliability of VOC data in several of the NHANES cohorts and its applicability as an exposure indicator, as demonstrated by the modest correlation between VOC levels in blood and personal air

  3. Inferences about Variance Components and Reliability-Generalizability Coefficients in the Absence of Random Sampling.

    Science.gov (United States)

    Kane, Michael

    2002-01-01

    Reviews the criticisms of sampling assumptions in generalizability theory (and in reliability theory) and examines the feasibility of using representative sampling, stratification, homogeneity assumptions, and replications to address these criticisms. Suggests some general outlines for the conduct of generalizability theory studies. (SLD)

  4. Inclusion of mobile phone numbers into an ongoing population health survey in New South Wales, Australia: design, methods, call outcomes, costs and sample representativeness.

    Science.gov (United States)

    Barr, Margo L; van Ritten, Jason J; Steel, David G; Thackway, Sarah V

    2012-11-22

    In Australia telephone surveys have been the method of choice for ongoing jurisdictional population health surveys. Although it was estimated in 2011 that nearly 20% of the Australian population were mobile-only phone users, the inclusion of mobile phone numbers into these existing landline population health surveys has not occurred. This paper describes the methods used for the inclusion of mobile phone numbers into an existing ongoing landline random digit dialling (RDD) health survey in an Australian state, the New South Wales Population Health Survey (NSWPHS). This paper also compares the call outcomes, costs and the representativeness of the resultant sample to that of the previous landline sample. After examining several mobile phone pilot studies conducted in Australia and possible sample designs (screening dual-frame and overlapping dual-frame), mobile phone numbers were included into the NSWPHS using an overlapping dual-frame design. Data collection was consistent, where possible, with the previous years' landline RDD phone surveys and between frames. Survey operational data for the frames were compared and combined. Demographic information from the interview data for mobile-only phone users, both, and total were compared to the landline frame using χ2 tests. Demographic information for each frame, landline and the mobile-only (equivalent to a screening dual frame design), and the frames combined (with appropriate overlap adjustment) were compared to the NSW demographic profile from the 2011 census using χ2 tests. In the first quarter of 2012, 3395 interviews were completed with 2171 respondents (63.9%) from the landline frame (17.6% landline only) and 1224 (36.1%) from the mobile frame (25.8% mobile only). Overall combined response, contact and cooperation rates were 33.1%, 65.1% and 72.2% respectively. As expected from previous research, the demographic profile of the mobile-only phone respondents differed most (more that were young, males, Aboriginal

  5. Applying Exploratory Structural Equation Modeling to Examine the Student-Teacher Relationship Scale in a Representative Greek Sample.

    Science.gov (United States)

    Tsigilis, Nikolaos; Gregoriadis, Athanasios; Grammatikopoulos, Vasilis; Zachopoulou, Evridiki

    2018-01-01

    Teacher-child relationships in early childhood are a fundamental prerequisite for children's social, emotional, and academic development. The Student-Teacher Relationship Scale (STRS) is one of the most widely accepted and used instruments that evaluate the quality of teacher-child relationships. STRS is a 28-item questionnaire that assess three relational dimensions, Closeness, Conflict, and Dependency. The relevant literature has shown a pattern regarding the difficulty to support the STRS factor structure with CFA, while it is well-documented with EFA. Recently, a new statistical technique was proposed to combine the best of the CFA and EFA namely, the Exploratory Structural Equation Modeling (ESEM). The purpose of this study was (a) to examine the factor structure of the STRS in a Greek national sample. Toward this end, the ESEM framework was applied in order to overcome the limitations of EFA and CFA, (b) to confirm previous findings about the cultural influence in teacher-child relationship patterns, and (c) to examine the invariance of STRS across gender and age. Early educators from a representative Greek sample size of 535 child care and kindergarten centers completed the STRS for 4,158 children. CFA as well as ESEM procedures were implemented. Results showed that ESEM provided better fit to the data than CFA in both groups, supporting the argument that CFA is an overly restrictive approach in comparison to ESEM for the study of STRS. All primary loadings were statistically significant and were associated with their respective latent factors. Contrary to the existing literature conducted in USA and northern Europe, the association between Closeness and Dependency yielded a positive correlation. This finding is in line with previous studies conducted in Greece and confirm the existence of cultural differences in teacher-child relationships. In addition, findings supported the configural, metric, scalar, and variance/covariance equivalence of the STRS

  6. Applying Exploratory Structural Equation Modeling to Examine the Student-Teacher Relationship Scale in a Representative Greek Sample

    Directory of Open Access Journals (Sweden)

    Nikolaos Tsigilis

    2018-05-01

    Full Text Available Teacher-child relationships in early childhood are a fundamental prerequisite for children's social, emotional, and academic development. The Student-Teacher Relationship Scale (STRS is one of the most widely accepted and used instruments that evaluate the quality of teacher-child relationships. STRS is a 28-item questionnaire that assess three relational dimensions, Closeness, Conflict, and Dependency. The relevant literature has shown a pattern regarding the difficulty to support the STRS factor structure with CFA, while it is well-documented with EFA. Recently, a new statistical technique was proposed to combine the best of the CFA and EFA namely, the Exploratory Structural Equation Modeling (ESEM. The purpose of this study was (a to examine the factor structure of the STRS in a Greek national sample. Toward this end, the ESEM framework was applied in order to overcome the limitations of EFA and CFA, (b to confirm previous findings about the cultural influence in teacher-child relationship patterns, and (c to examine the invariance of STRS across gender and age. Early educators from a representative Greek sample size of 535 child care and kindergarten centers completed the STRS for 4,158 children. CFA as well as ESEM procedures were implemented. Results showed that ESEM provided better fit to the data than CFA in both groups, supporting the argument that CFA is an overly restrictive approach in comparison to ESEM for the study of STRS. All primary loadings were statistically significant and were associated with their respective latent factors. Contrary to the existing literature conducted in USA and northern Europe, the association between Closeness and Dependency yielded a positive correlation. This finding is in line with previous studies conducted in Greece and confirm the existence of cultural differences in teacher-child relationships. In addition, findings supported the configural, metric, scalar, and variance/covariance equivalence of

  7. Mental health and resiliency following 44 months of terrorism: a survey of an Israeli national representative sample

    Science.gov (United States)

    Bleich, Avi; Gelkopf, Marc; Melamed, Yuval; Solomon, Zahava

    2006-01-01

    Background Israeli citizens have been exposed to intense and ongoing terrorism since September 2000. We previously studied the mental health impact of terrorism on the Israeli population (Bleich et al., 2002), however the long-term impact of ongoing terrorism has not yet been examined. The present study evaluated the psychological sequelae of 44 months of terrorism in Israel, and sought to identify factors that may contribute to vulnerability and resilience. Methods This was a telephone survey using strata sampling of 828 households, which reached a representative sample of 702 adult Israeli residents (84.8% contact rate). In total, 501 people (60.5%) agreed to participate. The methodology was similar to that of our previous study. Exposure to terrorism and other traumatic events, number of traumatic stress-related symptoms (TSRS), percentage of respondents with symptom criteria for post-traumatic stress disorder (PTSD), traumatic stress (TS) resiliency and feelings of depression, anxiety, optimism, sense of safety, and help-seeking were the main outcome measures. Results In total, 56 participants (11.2%) were directly exposed to a terrorist incident, and 101 (20.2%) had family members or friends exposed. Respondents reported a mean ± SD of 5.0 ± 4.5 TSRS; 45 (9%) met symptom criteria for PTSD; and 72 (14.4%) were TS-resilient. There were 147 participants (29.5%) who felt depressed, 50 (10.4%) felt anxious, and almost half (235; 47%) felt life-threatening danger; 48 (9.7%) felt the need for professional help. Women and people of Arab ethnicity had more TSRS, more PTSD, and less TS resiliency. Injury following a life-threatening experience, a major stressful life event, and a major loss of income were associated with PTSD. Immigrant status, lower education, low sense of safety, low sense of social support, high societal distress, and injury following life-threatening experiences were associated with TSRS. TSRS did not increase with exposure severity. This study

  8. Pattern analysis of total item score and item response of the Kessler Screening Scale for Psychological Distress (K6 in a nationally representative sample of US adults

    Directory of Open Access Journals (Sweden)

    Shinichiro Tomitaka

    2017-02-01

    Full Text Available Background Several recent studies have shown that total scores on depressive symptom measures in a general population approximate an exponential pattern except for the lower end of the distribution. Furthermore, we confirmed that the exponential pattern is present for the individual item responses on the Center for Epidemiologic Studies Depression Scale (CES-D. To confirm the reproducibility of such findings, we investigated the total score distribution and item responses of the Kessler Screening Scale for Psychological Distress (K6 in a nationally representative study. Methods Data were drawn from the National Survey of Midlife Development in the United States (MIDUS, which comprises four subsamples: (1 a national random digit dialing (RDD sample, (2 oversamples from five metropolitan areas, (3 siblings of individuals from the RDD sample, and (4 a national RDD sample of twin pairs. K6 items are scored using a 5-point scale: “none of the time,” “a little of the time,” “some of the time,” “most of the time,” and “all of the time.” The pattern of total score distribution and item responses were analyzed using graphical analysis and exponential regression model. Results The total score distributions of the four subsamples exhibited an exponential pattern with similar rate parameters. The item responses of the K6 approximated a linear pattern from “a little of the time” to “all of the time” on log-normal scales, while “none of the time” response was not related to this exponential pattern. Discussion The total score distribution and item responses of the K6 showed exponential patterns, consistent with other depressive symptom scales.

  9. The relationship between child abuse, parental divorce, and lifetime mental disorders and suicidality in a nationally representative adult sample.

    Science.gov (United States)

    Afifi, Tracie O; Boman, Jonathan; Fleisher, William; Sareen, Jitender

    2009-03-01

    To determine how the experiences of child abuse and parental divorce are related to long-term mental health outcomes using a nationally representative adult sample after adjusting for sociodemographic variables and parental psychopathology. Data were drawn from the National Comorbidity Survey (NCS, n=5,877; age 15-54 years; response rate 82.4%). Logistic regression models were used to determine the odds of experiencing lifetime psychiatric disorders and suicidal ideation and attempts. Parental divorce alone was associated with some psychiatric disorders after adjusting for sociodemographic variables (AOR ranging from 1.30 to 2.37), while child abuse alone was associated with psychiatric disorders (AOR ranging from 1.39 to 6.07) and suicidal ideation (AOR=2.08; 95% CI=1.57-2.77) and attempts (AOR=1.54; 95% CI=1.02-2.31) after adjusting for sociodemographic variables. However, having experienced both parental divorce and child abuse together resulted in significantly increased odds for lifetime PTSD (AOR=9.87; 95% CI=6.69-14.55), conduct disorder (AOR=4.01; 95% CI=2.92-5.51) and suicide attempts (AOR=2.74; 95% CI=1.84-4.08) compared to having experienced either parental divorce or child abuse alone. These results were attenuated when further adjusting for parental psychopathology. When the experience of parental divorce is accompanied with child abuse, the associations with some poor mental health outcomes are significantly greater compared to the impact of either parental divorce or child abuse on its own. Therefore, parental divorce is an additional childhood adversity that significantly contributes to poor mental health outcomes especially when in combination with child abuse. Parental psychopathology attenuated these relationships suggesting that it may be one possible mechanism to explain the relationships between child abuse, parental divorce, and psychiatric disorders and suicide attempts.

  10. The prevalence of couple infertility in the United States from a male perspective: evidence from a nationally representative sample.

    Science.gov (United States)

    Louis, J F; Thoma, M E; Sørensen, D N; McLain, A C; King, R B; Sundaram, R; Keiding, N; Buck Louis, G M

    2013-09-01

    Infertility is a couple-based fecundity impairment, although population level research is largely based upon information reported by female partners. Of the few studies focusing on male partners, most focus on the utilization of infertility services rather than efforts to estimate the prevalence and determinants of infertility as reported by male partners. Data from a nationally representative sample of men aged 15-44 years who participated in the 2002 National Survey of Family Growth (NSFG) were used to estimate the prevalence of infertility and determinants of longer time-to-pregnancy (TTP) using the novel current duration (CD) approach. Using backward recurrence time parametric survival methods, we estimated infertility prevalence (TTP > 12 months) and time ratios (TR) associated with TTP as derived from males' reported CD of their pregnancy attempt. The estimated prevalence of infertility was 12.0% (95% CI: 7.0, 23.2). Longer TTP was associated with older male age (35-45 vs. 17-24 years) (TR: 2.49; 95% CI: 1.03, 6.03), biological childlessness (TR: 1.53; 95% CI: 1.07, 2.19) and lack of health insurance (TR: 1.73; 95% CI: 1.02, 2.94) after controlling for the differences in couples' age and other socioeconomic factors. The prevalence of infertility based on male reporting is consistent with estimates of infertility in the US found in prospective cohort studies and CD studies based on female reporting. Our findings suggest that male partners can reliably inform about couple infertility. Interventions and services aimed at reducing couple infertility should include attention to male factors associated with longer TTP identified in this study. © 2013 American Society of Andrology and European Academy of Andrology.

  11. Can Nonurgent Emergency Department Care Costs be Reduced? Empirical Evidence from a U.S. Nationally Representative Sample.

    Science.gov (United States)

    Xin, Haichang; Kilgore, Meredith L; Sen, Bisakha Pia; Blackburn, Justin

    2015-09-01

    A well-functioning primary care system has the capacity to provide effective care for patients to avoid nonurgent emergency department (ED) use and related costs. This study examined how patients' perceived deficiency in ambulatory care is associated with nonurgent ED care costs nationwide. This retrospective cohort study used data from the 2010-2011 Medical Expenditure Panel Survey. This study chose usual source of care, convenience of needed medical care, and patient evaluation of care quality as the main independent variables. The marginal effect following a multivariate logit model was employed to analyze the urgent vs. nonurgent ED care costs in 2011, after controlling for covariates in 2010. The endogeneity was accounted for by the time lag effect and controlling for education levels. Sample weights and variance were adjusted with the survey procedures to make results nationally representative. Patient-perceived poor and intermediate levels of primary care quality had higher odds of nonurgent ED care costs (odds ratio [OR] = 2.22, p = 0.035, and OR = 2.05, p = 0.011, respectively) compared to high-quality care, with a marginal effect (at means) of 13.0% and 11.5% higher predicted probability of nonurgent ED care costs. Costs related to these ambulatory care quality deficiencies amounted to $229 million for private plans (95% confidence interval [CI] $100 million-$358 million), $58.5 million for public plans (95% CI $33.9 million-$83.1 million), and an overall of $379 million (95% CI $229 million-$529 million) nationally. These findings highlight the improvement in ambulatory care quality as the potential target area to effectively reduce nonurgent ED care costs. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. The Emergence of Spanking Among a Representative Sample of Children Under 2 Years of Age in North Carolina

    Science.gov (United States)

    Zolotor, Adam J.; Robinson, T. Walker; Runyan, Desmond K.; Barr, Ronald G.; Murphy, Robert A.

    2011-01-01

    Spanking is common in the United States but less common in many European countries in which it has been outlawed. Being spanked has been associated with child abuse victimization, poor self-esteem, impaired parent–child relationships, and child and adult mental health, substance abuse, and behavioral consequences. Being spanked as a child has also been shown to increase the likelihood of abusing one's own children or spouse as an adult. Spanking of very young children less than two is almost never recommended even among experts that consider spanking as reasonable in some circumstances. Using a cross-sectional anonymous telephone survey, we describe spanking rates among a representative sample of North Carolina mothers of children less than 2 years old and the association of spanking with demographic characteristics. A substantial proportion of mothers admit to spanking their very young children. The rate of spanking in the last year among all maternal respondents was 30%. Over 5% of the mothers of 3-month olds reported spanking. Over 70% of the mothers of 23-month olds reported spanking. Increased spanking was associated with higher age of the child and lower maternal age. With every month of age, a child had 27% increased odds of being spanked. Early spanking has been shown to be associated with poor cognitive development in early childhood. Further, early trauma has been shown to have significant effects on the early developing brain. It is therefore critical that health and human services professionals address the risk of corporal punishment as a method of discipline early in the life of the child. The spanking of very young children may be an appropriate locus for policy and legislative debates regarding corporal punishment. PMID:21738509

  13. Premenstrual dysphoric disorder as a correlate of suicidal ideation, plans, and attempts among a nationally representative sample.

    Science.gov (United States)

    Pilver, Corey E; Libby, Daniel J; Hoff, Rani A

    2013-03-01

    Suicide is a major public health concern and a leading cause of death in the United States. Psychopathology is an established risk factor for non-fatal suicidal behavior; however, it is unclear whether premenstrual dysphoric disorder (PMDD), a psychiatric disorder specific to women, is correlated with these outcomes. The objective of this study was to determine if PMDD status was associated with suicidal ideation, plans, and attempts, independent of socio-demographic factors and psychiatric comorbidity. We conducted a secondary data analysis of 3,965 American women aged 18-40 who participated in the Collaborative Psychiatric Epidemiology Survey. Descriptive statistics and forward stepwise logistic regression modeling were performed using SUDAAN software. The prevalence of non-fatal suicidal behaviors increased in a graded fashion according to PMDD status. Although the control for demographic characteristics and psychiatric comorbidity greatly attenuated the unadjusted association between PMDD and suicidal behaviors, women with PMDD remained significantly more likely than women with no premenstrual symptoms to report suicidal ideation (OR 2.22; 95% CI 1.40-3.53), plans (OR 2.27; 95% CI 1.20-4.28), and attempts (OR 2.10; 95% CI 1.08-4.08). Only the likelihood of suicidal ideation was significantly elevated among women with moderate/severe premenstrual syndrome (PMS; OR 1.49; 95% CI 1.17-1.88), compared to women with no premenstrual symptoms. PMDD was strongly and independently associated with non-fatal suicidal behaviors among a nationally representative sample. These findings suggest that clinicians treating women with PMDD should assess and be vigilant for signs of non-fatal suicidal behavior, and that clinicians should evaluate and treat the premenstrual symptoms of women who express these behaviors.

  14. Workplace psychosocial factors associated with work-related injury absence: a study from a nationally representative sample of Korean workers.

    Science.gov (United States)

    Lu, Ming-Lun; Nakata, Akinori; Park, Jae Bum; Swanson, Naomi G

    2014-02-01

    Little is known about the association between psychosocial factors and injury absence in the workplace. This study aims to assess the association of comprehensive workplace psychosocial factors with work-related injury absence among Korean workers. The data (n = 7,856) were derived from the First Korean Working Conditions Survey conducted in 2006 with a representative sample (n = 10,043) of the Korean working population. The survey instrument contained questions about hours of work, physical risk factors, work organization, and the effect of work on health/injury. Work-related injury absence was indicated by a dichotomous variable with at least 1 day absence during the preceding 12 months. Logistic regression models were used to calculate odds ratio and confidence interval (CI). Incremental adjustments for sociodemographic, health behavior, and occupational confounding variables were employed in the models. The overall 1-year prevalence of work-related injury absence in this study was 1.37 % (95 % CI, 1.11-1.63 %). Those who experienced violence at work (adjusted odds ratio (aOR), 7.05 (95 % CI, 2.69-18.5)), threat of violence at work (aOR, 4.25 (95 % CI, 1.32-13.64)), low job autonomy (aOR, 1.79 (95 % CI, 1.17-2.74)), and high job strain (aOR, 2.38 (95 % CI, 1.29-4.42) had an increased risk of injury absence, compared with their respective counterparts (p workers in Korea were at a near fourfold risk of work absence due to occupational injuries, compared with managers in low-risk jobs. Workplace violence and increased job strain were two key workplace psychosocial factors associated with work-related injury absence.

  15. Child maltreatment and eating disorders among men and women in adulthood: Results from a nationally representative United States sample.

    Science.gov (United States)

    Afifi, Tracie O; Sareen, Jitender; Fortier, Janique; Taillieu, Tamara; Turner, Sarah; Cheung, Kristene; Henriksen, Christine A

    2017-11-01

    Child maltreatment is associated with an increased likelihood of having mood disorders, anxiety disorders, post-traumatic stress disorder, substance use disorders, and personality disorders, but far less is known about eating disorders. The objective of the current study was to examine the associations between child maltreatment, including harsh physical punishment, physical abuse, sexual abuse, emotional abuse, emotional neglect, physical neglect, and exposure to intimate partner violence, and eating disorders in adulthood among men and women. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions wave 3 (NESARC-III) collected in 2012-2013. The sample was nationally representative of the United States adult population (N = 36,309). Lifetime eating disorders (anorexia nervosa [AN], bulimia nervosa [BN], and binge-eating disorder [BED]) were assessed using diagnostic and statistical manual of mental disorders, fifth edition (DSM-5) criteria and the alcohol use disorder and associated disabilities interview schedule-5 (AUDADIS-5). The prevalence of any lifetime eating disorder was 1.7% (0.8% among men and 2.7% among women). All child maltreatment types were associated with AN, BN, and BED with notable differences among men and women. Overall, the types of child maltreatment with the strongest relationships with any eating disorder were sexual abuse and physical neglect among men and sexual abuse and emotional abuse among women. Clinicians should be mindful that child maltreatment experiences are associated with increased odds of eating disorders including AN, BED, and BN. Such relationships are significant among men and women although notable gender differences in these relationships exist. Abstract word count = 248. © 2017 The Authors International Journal of Eating Disorders Published by Wiley Periodicals, Inc.

  16. Mental health problems and their association to violence and maltreatment in a nationally representative sample of Tanzanian secondary school students.

    Science.gov (United States)

    Nkuba, Mabula; Hermenau, Katharin; Goessmann, Katharina; Hecker, Tobias

    2018-04-12

    Little is known about the prevalence of mental health problems among adolescents in Sub-Saharan Africa. Research consistently determined violence and maltreatment to be important risk factors. In this study, we examined the prevalence of mental health problems among adolescents in Tanzania, as well as the association with exposure to violence and maltreatment. We administered a set of questionnaires (e.g., strength and difficulties questionnaire; conflict tactic scale) to a nationally representative sample of 700 Tanzanian secondary school children (52% girls; age 14.92 years, SD = 1.02) and 333 parents or primary caregivers (53% females; age 43.47 years, SD = 9.02). 41% of the students reported an elevated level of mental health problems (emotional problems 40%, peer problems 63%, conduct problems 45%, hyperactivity 17%) in the past 6 months. Concordantly, 31% of parents reported observing an elevated level of mental health problems in their children (emotional problems 37%, peer problems 54%, conduct problems 35%, hyperactivity 17%). After controlling for other risk factors, we found significant associations between physical violence by parents and adolescent's mental health problems reported by students (β = 0.15) and their parents (β = 0.33). Our findings suggest a high prevalence of mental health problems using screening tools among secondary school students in Tanzania as well as an association between physical violence by parents and adolescents' mental health problems. Our findings emphasize the need to inform the population at large about the potentially adverse consequences associated with violence against children and adolescents.

  17. Application of morphological and physiological parameters representative of a sample Brazilian population in the human respiratory tract model

    International Nuclear Information System (INIS)

    Reis, A.A.; Cardoso, J.C.S.; Lourenco, M.C.

    2005-01-01

    Full text: The Human Respiratory Tract Model (HRTM) proposed in ICRP Publication 66 account for the morphology and physiology of the respiratory tract. The characteristics of air drawn into the lungs and exhaled are greatly influenced by the morphology of the respiratory tract, which causes numerous changes in pressure, flow rate, direction and humidity as air moves into and out of the lungs. These changing characteristics can influence the rates and the sites of deposition. Concerning the respiratory physiological parameters the breathing characteristics influence the volume, the inhalation rate of air and the portion that enters through the nose and the mouth. These characteristics are important to determine the fractional deposition. The HRTM model uses morphological and physiological parameters from the Caucasian man to establish deposition fractions in the respiratory tract regions. lt is known that the morphology and physiology are influenced by environmental, occupational and economic conditions. The ICRP recommends for a reliable evaluation of the regional deposition the use of parameters from a local population when information is available. The main purpose of this study is to verify the influence in using the morphology and physiology parameters representative of a sample of the Brazilian population on the deposition model of ICRP Publication 66. The morphological and physiological data were obtained from the literature. The software EXCEL for Windows (version 2000) was used in order to implement the deposition model and also to allow the changes in parameters of interest. Initially, the implemented model was checked using the parameters defined in ICRP and the results of the fraction deposition in the respiratory tract compartments were compared. Finally, morphological and physiological parameters from Brazilian adult male were applied and the fractional deposition calculated. The respiratory values at different levels of activity for ages varying from

  18. Relationship between sleep characteristics and measures of body size and composition in a nationally-representative sample.

    Science.gov (United States)

    Xiao, Qian; Gu, Fangyi; Caporaso, Neil; Matthews, Charles E

    2016-01-01

    Short sleep has been linked to obesity. However, sleep is a multidimensional behavior that cannot be characterized solely by sleep duration. There is limited study that comprehensively examined different sleep characteristics in relation to obesity. We examined various aspects of sleep in relation to adiposity in 2005-2006 NHANES participants who were 18 or older and free of cardiovascular disease, cancer, emphysema, chronic bronchitis and depression ( N  = 3995). Sleep characteristics were self-reported, and included duration, overall quality, onset latency, fragmentation, daytime sleepiness, snoring, and sleep disorders. Body measurements included weight, height, waist circumference, and dual-energy X-ray absorptiometry measured fat mass. Snoring was associated with higher BMI (adjusted difference in kg/m 2 comparing snoring for 5+ nights/week with no snoring (95 % confidence interval), 1.85 (0.88, 2.83)), larger waist circumference (cm, 4.52 (2.29, 6.75)), higher percentage of body fat (%, 1.61 (0.84, 2.38)), and higher android/gynoid ratio (0.03 (0.01, 0.06)). The associations were independent of sleep duration and sleep quality, and cannot be explained by the existence of sleep disorders such as sleep apnea. Poor sleep quality (two or more problematic sleep conditions) and short sleep duration (body size and fat composition, although the effects were attenuated after snoring was adjusted. In a nationally representative sample of healthy US adults, snoring, short sleep, and poor sleep quality were associated with higher adiposity.

  19. Problematic Internet Use and Problematic Online Gaming Are Not the Same: Findings from a Large Nationally Representative Adolescent Sample

    Science.gov (United States)

    Griffiths, Mark D.; Urbán, Róbert; Farkas, Judit; Kökönyei, Gyöngyi; Elekes, Zsuzsanna; Tamás, Domokos; Demetrovics, Zsolt

    2014-01-01

    Abstract There is an ongoing debate in the literature whether problematic Internet use (PIU) and problematic online gaming (POG) are two distinct conceptual and nosological entities or whether they are the same. The present study contributes to this question by examining the interrelationship and the overlap between PIU and POG in terms of sex, school achievement, time spent using the Internet and/or online gaming, psychological well-being, and preferred online activities. Questionnaires assessing these variables were administered to a nationally representative sample of adolescent gamers (N=2,073; Mage=16.4 years, SD=0.87; 68.4% male). Data showed that Internet use was a common activity among adolescents, while online gaming was engaged in by a considerably smaller group. Similarly, more adolescents met the criteria for PIU than for POG, and a small group of adolescents showed symptoms of both problem behaviors. The most notable difference between the two problem behaviors was in terms of sex. POG was much more strongly associated with being male. Self-esteem had low effect sizes on both behaviors, while depressive symptoms were associated with both PIU and POG, affecting PIU slightly more. In terms of preferred online activities, PIU was positively associated with online gaming, online chatting, and social networking, while POG was only associated with online gaming. Based on our findings, POG appears to be a conceptually different behavior from PIU, and therefore the data support the notion that Internet Addiction Disorder and Internet Gaming Disorder are separate nosological entities. PMID:25415659

  20. Depression, obesity, and metabolic syndrome: prevalence and risks of comorbidity in a population-based representative sample of Mexican Americans.

    Science.gov (United States)

    Olvera, Rene L; Williamson, Douglas E; Fisher-Hoch, Susan P; Vatcheva, Kristina P; McCormick, Joseph B

    2015-10-01

    We examined the prevalence of depression, obesity, and metabolic syndrome and associations between them in a population-based representative cohort of Mexican Americans living on the United States-Mexico border. The sample in this cross-sectional analysis consisted of 1,768 Mexican American adults (≥ 18 years of age) assessed between the years 2004 and 2010, with whom we tested our central hypothesis of a significant relationship between obesity and depression. Depression was measured using the Center for Epidemiologic Studies-Depression scale (CES-D) with a cutoff score of ≥ 16 for depression and a cutoff score of ≥ 27 for severe depression. We categorized body mass index (BMI) values as obese (≥ 30kg/m(2)) and later subdivided the obese subjects into obese (30-39 kg/m(2)[inclusive]) and morbidly obese (≥ 40 kg/m(2)). Metabolic syndrome was defined using the American Heart Association definition requiring at least 3 of the following: increased waist circumference, elevated triglycerides, reduced high-density lipoprotein (HDL) cholesterol, elevated blood pressure, and elevated fasting glucose. Weighted data were analyzed to establish prevalence of depression, obesity, and metabolic syndrome. Univariate and multivariable weighted regression models were used to test potential associations between these disorders. Using weighted prevalence, we observed high rates of depression (30%), obesity (52%), and metabolic syndrome (45%). Univariate models revealed female gender (P = .0004), low education (P = .003), low HDL level (P = .009), and increased waist circumference (P = .03) were associated with depression. Female gender (P = .01), low education (P = .003), and morbid obesity (P = .002) were risk factors for severe depression and remained significant in multivariable models. In this large cohort of Mexican Americans, obesity, female gender, and low education were identified risk factors for depression. These indicators may serve as targets for early

  1. Men's use and perceptions of commercial lubricants: prevalence and characteristics in a nationally representative sample of American adults.

    Science.gov (United States)

    Reece, Michael; Herbenick, Debby; Schick, Vanessa; Sanders, Stephanie A; Fortenberry, J Dennis

    2014-05-01

    Most research on men's use of commercial lubricants during sexual activities is in the context of condom use and often specifically among men who have sex with men. Less is known about men's use of lubricants associated with a broader range of sexual experiences. The aims of this study are to document the prevalence of commercial lubricant use among adult U.S. men (age 18+), to document men's use of lubricants across solo and partnered sexual behaviors, and to assess men's perceptions of the contributions lubricants have to the sexual experience. Data are from the 2012 National Survey of Sexual Health and Behavior, which involved the administration of an online questionnaire to a nationally representative probability sample of U.S. adults ages 18 and older. Sociodemographic characteristics, recent and lifetime commercial lubricant use, lubricant use during specific sexual behaviors, frequency of lubricant use, and reasons for lubricant use. Most men in the United States (70%, N = 1,014) reported having used a commercial lubricant, with men older than 24 and those in a relationship more likely to report lubricant use. About one in four men had used a lubricant in the past 30 days. Intercourse was the most common behavior during which men used lubricant, though solo masturbation and partnered sexual play were also frequently linked to lubricant use. The most common reasons for lubricant use included "to make sex more comfortable," "for fun," "curiosity," and "my partner wanted to." Most American men have used a lubricant; lubricant use is common across all age groups, and some of the most common reasons why men report using lubricants have to do with sexual enhancement, comfort, and pleasure. Clinicians may find these data helpful to their efforts to educate patients about lubricant use, comfort during sex, and sexual enhancement. © 2014 International Society for Sexual Medicine.

  2. Smoking and its risk factors in Chinese elementary and middle school students: a nationally representative sample study.

    Science.gov (United States)

    Zhang, Xinghui; Li, Yajun; Zhang, Qin; Lu, Furong; Wang, Yun

    2014-05-01

    The purpose of this study was to examine the prevalence of smoking in a nationally representative sample of Chinese elementary and middle school students and to investigate its risk factors from families and schools. The data were from the National Children's Study of China (NCSC), in which 24,013 fourth- to ninth-grade students were recruited from 100 counties in 31 provinces in China. Chi-square tests and one-way ANOVAs were used to analyze the relationships between smoking and the risk factors. Logistic regressions were used to calculate odds ratios. The prevalence of ever smokers and current smokers were 19.0% and 5.4%. Focusing on current smokers, boys, middle school students, rural students, boarding students, non-only children and those owning parents with low educational levels reported smoking significantly more than girls, elementary school students, urban students, non-boarding students, only children and those owning parents with high educational levels. Lower trust and support from teachers and higher parent-child conflict positively predicted both smoking and smoking frequency. Lower trust and support from classmates was associated with higher possibility of smoking. However, higher trust and support from classmates was associated with higher smoking frequency. Teacher smoking and friend smoking were only predictive of smoking, but not of smoking frequency. Boys, middle school students, rural students, boarding students, non-only children and those owning parents with low educational levels need special attention. The most risk factors for smoking and smoking frequency were lower trust and support from teachers and higher parent-child conflict. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Protective factors for mental disorders and psychological distress in female, compared with male, service members in a representative sample.

    Science.gov (United States)

    Mota, Natalie P; Medved, Maria; Whitney, Debbie; Hiebert-Murphy, Diane; Sareen, Jitender

    2013-10-01

    Although military interest in promoting psychological resilience is growing, resources protective against psychopathology have been understudied in female service members. Using a representative sample of Canadian Forces personnel, we investigated whether religious attendance, spirituality, coping, and social support were related to mental disorders and psychological distress in female service members, and whether sex differences occurred in these associations. Religious attendance and spirituality were self-reported. Coping items were taken from 3 scales and produced 3 factors (active, avoidance, and self-medication). Social support was assessed with the Medical Outcomes Study Social Support Survey. Past-year mental disorders were diagnosed with the World Mental Health Composite International Diagnostic Interview. The Kessler Psychological Distress Scale assessed distress. Multivariate regression models investigated links between correlates and psychological outcomes within each sex. For associations that were statistically significant in only one sex, sex by correlate interactions were computed. In female service members, inverse relations were found between social support and MDD, any MDD or anxiety disorder, suicidal ideation, and distress. No associations were found between religious attendance and outcomes, and spirituality was associated with an increased likelihood of some outcomes. Active coping was related to less psychological distress, while avoidance coping and self-medication were linked to a higher likelihood of most outcomes. Although several statistically significant associations were found in only one sex, only one sex by correlate interaction was statistically significant. Social support was found to be inversely related to several negative mental health outcomes in female service members. Few differences between men and women reached statistical significance. Future research should identify additional helpful resources for female service members.

  4. The emergence of spanking among a representative sample of children under two years of age in North Carolina.

    Directory of Open Access Journals (Sweden)

    Adam J. Zolotor

    2011-06-01

    Full Text Available Spanking is common in the United States but less common in many European countries in which it has been outlawed. Being spanked has been associated with child abuse victimization, poor self-esteem, impaired parent-child relationships, and child and adult mental health, substance abuse, and behavioral consequences. Being spanked as a child has also been shown to increase the likelihood of abusing one’s own children or spouse as an adult. Spanking of very young children less than two is almost never recommended even among experts that consider spanking as reasonable in some circumstances. Using a cross-sectional anonymous telephone survey, we describe spanking rates among a representative sample of North Carolina mothers of children less than two years old and the association of spanking with demographic characteristics.A substantial proportion of mothers admit to spanking their very young children. The rate of spanking in the last year among all maternal respondents was 30%. Over 5% of the mothers of three month olds reported spanking. Over 70% of the mothers of 23 month olds reported spanking. Increased spanking was associated with higher age of the child and lower maternal age. With every month of age, a child had 27% increased odds of being spanked. Early spanking has been shown to be associated with poor cognitive development in early childhood. Further, early trauma has been shown to have significant effects on the early developing brain. It is therefore critical that health and human services professionals addres the risk of corporal punishment as a method of discipline early in the life of the child. The spanking of very young children may be an appropriate locus for policy and legislative debates regarding corporal punishment.

  5. Blood pressure and its influencing factors in a national representative sample of Iranian children and adolescents: the CASPIAN Study.

    Science.gov (United States)

    Kelishadi, Roya; Ardalan, Gelayol; Gheiratmand, Riaz; Majdzadeh, Reza; Delavari, Alireza; Heshmat, Ramin; Gouya, Mohammad Mehdi; Razaghi, Emran Mohammad; Motaghian, Molouk; Mokhtari, Mohammad Reza; Barekati, Hamed; Arabi, Minoo Sadat Mahmoud

    2006-12-01

    This study was performed to determine the blood pressure (BP) percentile curves by height, as well as to assess the prevalence of high BP and its influencing factors among children in the first national survey in this field in Iran. A multicentre national cross-sectional survey. This study was performed in 23 provinces among a representative sample of 21,111 students aged 6-18 years. Age and sex-specific percentile curves of systolic and diastolic BP were obtained by height. A comparison of the values obtained corresponding to the 90th percentiles with the Second Task Force cut-offs showed that the BP values and trends were relatively similar in both studies. The overall prevalence of systolic, diastolic as well as systolic or diastolic hypertension according to the Second Task Force study 95th percentile cut-off points were 4.2, 5.4 and 7.7%, respectively, without a significant sex difference. A history of low birthweight, overweight, taller height, the consumption of solid hydrogenated fat, as well as the frequency of fast food consumption increased the risk of both systolic and diastolic hypertension. Male sex, large waist, and low education of the mother were the risks for systolic hypertension, whereas the risk of diastolic hypertension rose with living in an urban area, attending public school, low physical activity level, having a housewife mother, and a positive family history of obesity, especially in the parents. Considering the effect of modifiable environmental factors on the childrens' BP, encouraging breast feeding and a healthy lifestyle may have an important effect on public health.

  6. The emergence of spanking among a representative sample of children under 2 years of age in north Carolina.

    Science.gov (United States)

    Zolotor, Adam J; Robinson, T Walker; Runyan, Desmond K; Barr, Ronald G; Murphy, Robert A

    2011-01-01

    Spanking is common in the United States but less common in many European countries in which it has been outlawed. Being spanked has been associated with child abuse victimization, poor self-esteem, impaired parent-child relationships, and child and adult mental health, substance abuse, and behavioral consequences. Being spanked as a child has also been shown to increase the likelihood of abusing one's own children or spouse as an adult. Spanking of very young children less than two is almost never recommended even among experts that consider spanking as reasonable in some circumstances. Using a cross-sectional anonymous telephone survey, we describe spanking rates among a representative sample of North Carolina mothers of children less than 2 years old and the association of spanking with demographic characteristics. A substantial proportion of mothers admit to spanking their very young children. The rate of spanking in the last year among all maternal respondents was 30%. Over 5% of the mothers of 3-month olds reported spanking. Over 70% of the mothers of 23-month olds reported spanking. Increased spanking was associated with higher age of the child and lower maternal age. With every month of age, a child had 27% increased odds of being spanked. Early spanking has been shown to be associated with poor cognitive development in early childhood. Further, early trauma has been shown to have significant effects on the early developing brain. It is therefore critical that health and human services professionals address the risk of corporal punishment as a method of discipline early in the life of the child. The spanking of very young children may be an appropriate locus for policy and legislative debates regarding corporal punishment.

  7. 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.

  8. Transactional relationships and sex with a woman in prostitution: prevalence and patterns in a representative sample of South African men.

    Science.gov (United States)

    Jewkes, Rachel; Morrell, Robert; Sikweyiya, Yandisa; Dunkle, Kristin; Penn-Kekana, Loveday

    2012-05-02

    Sex motivated by economic exchange is a public health concern as a driver of the Sub-Saharan African HIV epidemic. We describe patterns of engagement in transactional sexual relationships and sex with women in prostitution of South African men, and suggest interpretations that advance our understanding of the phenomenon. Cross-sectional study with a randomly-selected sample of 1645 sexually active men aged 18-49 years who completed interviews in a household study and were asked whether they had had sex with a woman in prostitution, or had had a relationship or sex they took to be motivated by the expectation of material gain (transactional sex). 18% of men had ever had sex with a woman in prostitution, 66% at least one type of transactional sexual relationship, only 30% of men had done neither. Most men had had a transactional relationship/sex with a main partner (58% of all men), 42% with a concurrent partner (or makhwapheni) and 44% with a once off partner, and there was almost no difference in reports of what was provided to women of different partner types. The majority of men distinguished the two types of sexual relationships and even among men who had once-off transactional sex and gave cash (n = 314), few (34%) reported that they had had sex with a 'prostitute'. Transactional sex was more common among men aged 25-34 years, less educated men and low income earners rather than those with none or higher income. Having had sex with a woman in prostitution varied little between social and demographic categories, but was less common among the unwaged or very low earners. The notion of 'transactional sex' developed through research with women does not translate easily to men. Many perceive expectations that they fulfil a provider role, with quid pro quo entitlement to sex. Men distinguished these circumstances of sex from having sex with a woman in prostitution. Whilst there may be similarities, when viewed relationally, these are quite distinct practices

  9. Mental health and psychosocial problems in the aftermath of the Nepal earthquakes: findings from a representative cluster sample survey.

    Science.gov (United States)

    Kane, J C; Luitel, N P; Jordans, M J D; Kohrt, B A; Weissbecker, I; Tol, W A

    2018-06-01

    Two large earthquakes in 2015 caused widespread destruction in Nepal. This study aimed to examine frequency of common mental health and psychosocial problems and their correlates following the earthquakes. A stratified multi-stage cluster sampling design was employed to randomly select 513 participants (aged 16 and above) from three earthquake-affected districts in Nepal: Kathmandu, Gorkha and Sindhupalchowk, 4 months after the second earthquake. Outcomes were selected based on qualitative preparatory research and included symptoms of depression and anxiety (Hopkins Symptom Checklist-25); post-traumatic stress disorder (PTSD Checklist-Civilian); hazardous alcohol use (AUDIT-C); symptoms indicating severe psychological distress (WHO-UNHCR Assessment Schedule of Serious Symptoms in Humanitarian Settings (WASSS)); suicidal ideation (Composite International Diagnostic Interview); perceived needs (Humanitarian Emergency Settings Perceived Needs Scale (HESPER)); and functional impairment (locally developed scale). A substantial percentage of participants scored above validated cut-off scores for depression (34.3%, 95% CI 28.4-40.4) and anxiety (33.8%, 95% CI 27.6-40.6). Hazardous alcohol use was reported by 20.4% (95% CI 17.1-24.3) and 10.9% (95% CI 8.8-13.5) reported suicidal ideation. Forty-two percent reported that 'distress' was a serious problem in their community. Anger that was out of control (symptom from the WASSS) was reported by 33.7% (95% CI 29.5-38.2). Fewer people had elevated rates of PTSD symptoms above a validated cut-off score (5.2%, 95% CI 3.9-6.8), and levels of functional impairment were also relatively low. Correlates of elevated symptom scores were female gender, lower caste and greater number of perceived needs. Residing in Gorkha and Sindhupalchowk districts and lower caste were also associated with greater perceived needs. Higher levels of impaired functioning were associated with greater odds of depression and anxiety symptoms; impaired

  10. Transactional relationships and sex with a woman in prostitution: prevalence and patterns in a representative sample of South African men

    Science.gov (United States)

    2012-01-01

    Background Sex motivated by economic exchange is a public health concern as a driver of the Sub-Saharan African HIV epidemic. We describe patterns of engagement in transactional sexual relationships and sex with women in prostitution of South African men, and suggest interpretations that advance our understanding of the phenomenon. Methods Cross-sectional study with a randomly-selected sample of 1645 sexually active men aged 18–49 years who completed interviews in a household study and were asked whether they had had sex with a woman in prostitution, or had had a relationship or sex they took to be motivated by the expectation of material gain (transactional sex). Results 18% of men had ever had sex with a woman in prostitution, 66% at least one type of transactional sexual relationship, only 30% of men had done neither. Most men had had a transactional relationship/sex with a main partner (58% of all men), 42% with a concurrent partner (or makhwapheni) and 44% with a once off partner, and there was almost no difference in reports of what was provided to women of different partner types. The majority of men distinguished the two types of sexual relationships and even among men who had once-off transactional sex and gave cash (n = 314), few (34%) reported that they had had sex with a ‘prostitute’. Transactional sex was more common among men aged 25–34 years, less educated men and low income earners rather than those with none or higher income. Having had sex with a woman in prostitution varied little between social and demographic categories, but was less common among the unwaged or very low earners. Conclusions The notion of ‘transactional sex’ developed through research with women does not translate easily to men. Many perceive expectations that they fulfil a provider role, with quid pro quo entitlement to sex. Men distinguished these circumstances of sex from having sex with a woman in prostitution. Whilst there may be similarities, when

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

    Directory of Open Access Journals (Sweden)

    Bo Yu

    2015-01-01

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

  12. 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...

  13. The Dirichet-Multinomial model for multivariate randomized response data and small samples

    NARCIS (Netherlands)

    Avetisyan, Marianna; Fox, Gerardus J.A.

    2012-01-01

    In survey sampling the randomized response (RR) technique can be used to obtain truthful answers to sensitive questions. Although the individual answers are masked due to the RR technique, individual (sensitive) response rates can be estimated when observing multivariate response data. The

  14. The Dirichlet-Multinomial Model for Multivariate Randomized Response Data and Small Samples

    Science.gov (United States)

    Avetisyan, Marianna; Fox, Jean-Paul

    2012-01-01

    In survey sampling the randomized response (RR) technique can be used to obtain truthful answers to sensitive questions. Although the individual answers are masked due to the RR technique, individual (sensitive) response rates can be estimated when observing multivariate response data. The beta-binomial model for binary RR data will be generalized…

  15. 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…

  16. A simple sample size formula for analysis of covariance in cluster randomized trials.

    NARCIS (Netherlands)

    Teerenstra, S.; Eldridge, S.; Graff, M.J.; Hoop, E. de; Borm, G.F.

    2012-01-01

    For cluster randomized trials with a continuous outcome, the sample size is often calculated as if an analysis of the outcomes at the end of the treatment period (follow-up scores) would be performed. However, often a baseline measurement of the outcome is available or feasible to obtain. An

  17. 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

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

    Science.gov (United States)

    Taylor, Laura; Doehler, Kirsten

    2015-01-01

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

  19. An efficient method of randomly sampling the coherent angular scatter distribution

    International Nuclear Information System (INIS)

    Williamson, J.F.; Morin, R.L.

    1983-01-01

    Monte Carlo simulations of photon transport phenomena require random selection of an interaction process at each collision site along the photon track. Possible choices are usually limited to photoelectric absorption and incoherent scatter as approximated by the Klein-Nishina distribution. A technique is described for sampling the coherent angular scatter distribution, for the benefit of workers in medical physics. (U.K.)

  20. Monitoring oil persistence on beaches : SCAT versus stratified random sampling designs

    International Nuclear Information System (INIS)

    Short, J.W.; Lindeberg, M.R.; Harris, P.M.; Maselko, J.M.; Pella, J.J.; Rice, S.D.

    2003-01-01

    In the event of a coastal oil spill, shoreline clean-up assessment teams (SCAT) commonly rely on visual inspection of the entire affected area to monitor the persistence of the oil on beaches. Occasionally, pits are excavated to evaluate the persistence of subsurface oil. This approach is practical for directing clean-up efforts directly following a spill. However, sampling of the 1989 Exxon Valdez oil spill in Prince William Sound 12 years later has shown that visual inspection combined with pit excavation does not offer estimates of contaminated beach area of stranded oil volumes. This information is needed to statistically evaluate the significance of change with time. Assumptions regarding the correlation of visually-evident surface oil and cryptic subsurface oil are usually not evaluated as part of the SCAT mandate. Stratified random sampling can avoid such problems and could produce precise estimates of oiled area and volume that allow for statistical assessment of major temporal trends and the extent of the impact. The 2001 sampling of the shoreline of Prince William Sound showed that 15 per cent of surface oil occurrences were associated with subsurface oil. This study demonstrates the usefulness of the stratified random sampling method and shows how sampling design parameters impact statistical outcome. Power analysis based on the study results, indicate that optimum power is derived when unnecessary stratification is avoided. It was emphasized that sampling effort should be balanced between choosing sufficient beaches for sampling and the intensity of sampling

  1. Prevalence and Correlates of Elopement in a Nationally Representative Sample of Children with Developmental Disabilities in the United States.

    Directory of Open Access Journals (Sweden)

    Bridget Kiely

    Full Text Available Despite increased awareness and concern about children with developmental disabilities wandering away from adult supervision, there is a paucity of research about elopement. This is the first study to examine and report the prevalence and correlates of elopement in a nationally representative sample of school-age children in the United States with an autism spectrum disorder (ASD and/or cognitive impairment. Data were obtained from the CDC's "Pathways" Survey, a follow-up telephone survey of the parents of 4,032 children with a developmental condition. 3,518 children that had ASD, intellectual disability (ID, and/or developmental delay (DD at the time of survey administration were included for analysis. Children were divided into three condition groups: ASD-only; ID/DD-only; ASD+ID/DD. Logistic regression analyses were used to compare the prevalence of elopement and rates of preventive measure use (barriers and/or electronic devices across condition groups, and to examine the clinical and demographic correlates of elopement. T-tests were also performed to compare scores on the Children's Social Behavior Questionnaire (CSBQ between wanderers and non-wanderers. Overall, 26.7% of children had reportedly eloped within the previous year, most commonly from public places. Children with ASD-only and ASD+ID/DD were more likely to have eloped than those with ID/DD-only. Across all groups, wanderers scored higher than non-wanderers on five out of six CSBQ subscales; they were more likely not to realize when there is danger, to have difficulty distinguishing between strangers and familiar people, to show sudden mood changes, to over-react to everything/everyone, to get angry quickly, to get lost easily, and to panic in new situations or if change occurs. Even after controlling for elopement history, parents of children in the ASD+ID/DD group were more likely than those in the other condition groups to report using physical or electronic measures to prevent

  2. The Bootstrap, the Jackknife, and the Randomization Test: A Sampling Taxonomy.

    Science.gov (United States)

    Rodgers, J L

    1999-10-01

    A simple sampling taxonomy is defined that shows the differences between and relationships among the bootstrap, the jackknife, and the randomization test. Each method has as its goal the creation of an empirical sampling distribution that can be used to test statistical hypotheses, estimate standard errors, and/or create confidence intervals. Distinctions between the methods can be made based on the sampling approach (with replacement versus without replacement) and the sample size (replacing the whole original sample versus replacing a subset of the original sample). The taxonomy is useful for teaching the goals and purposes of resampling schemes. An extension of the taxonomy implies other possible resampling approaches that have not previously been considered. Univariate and multivariate examples are presented.

  3. Blasthole sampling (replicate and variographic experiments) in LKAB open pit iron ore mines – fit-for-purpose representativity?

    DEFF Research Database (Denmark)

    Engström, Karin; Esbensen, Kim Harry

    2017-01-01

    The conclusion from the debate over the last decade in the mining sector is that, for grade control, reverse circulation (RC) drill sampling gives more reliable results due to less sampling problems than blasthole samples. However, by conducting the latter with well-controlled procedures there st...

  4. Prevalence of Hearing Loss Among a Representative Sample of Canadian Children and Adolescents, 3 to 19 Years of Age.

    Science.gov (United States)

    Feder, Katya Polena; Michaud, David; McNamee, James; Fitzpatrick, Elizabeth; Ramage-Morin, Pamela; Beauregard, Yves

    There are no nationally representative hearing loss (HL) prevalence data available for Canadian youth using direct measurements. The present study objectives were to estimate national prevalence of HL using audiometric pure-tone thresholds (0.5 to 8 kHz) and or distortion product otoacoustic emissions (DPOAEs) for children and adolescents, aged 3 to 19 years. This cross-sectional population-based study presents findings from the 2012/2013 Canadian Health Measures Survey, entailing an in-person household interview and hearing measurements conducted in a mobile examination clinic. The initial study sample included 2591 participants, aged 3 to 19 years, representing 6.5 million Canadians (3.3 million males). After exclusions, subsamples consisted of 2434 participants, aged 3 to 19 years and 1879 participants, aged 6 to 19 years, with valid audiometric results. Eligible participants underwent otoscopic examination, tympanometry, DPOAE, and audiometry. HL was defined as a pure-tone average >20 dB for 6- to 18-year olds and ≥26 dB for 19-year olds, for one or more of the following: four-frequency (0.5, 1, 2, and 4 kHz) pure-tone average, high-frequency (3, 4, 6, and 8 kHz) pure-tone average, and low-frequency (0.5, 1, and 2 kHz) pure-tone average. Mild HL was defined as >20 to 40 dB (6- to 18-year olds) and ≥26 to 40 dB (19-year olds). Moderate or worse HL was defined as >40 dB (6- to 19-year olds). HL in 3- to 5-year olds (n = 555) was defined as absent DPOAEs as audiometry was not conducted. Self-reported HL was evaluated using the Health Utilities Index Mark 3 hearing questions. The primary study outcome indicates that 7.7% of Canadian youth, aged 6 to 19, had any HL, for one or more pure-tone average. Four-frequency pure-tone average and high-frequency pure-tone average HL prevalence was 4.7 and 6.0%, respectively, whereas 5.8% had a low-frequency pure-tone average HL. Significantly more children/adolescents had unilateral HL. Mild HL was significantly

  5. Additive non-uniform random sampling in superimposed fiber Bragg grating strain gauge

    International Nuclear Information System (INIS)

    Ma, Y C; Liu, H Y; Yan, S B; Li, J M; Tang, J; Yang, Y H; Yang, M W

    2013-01-01

    This paper demonstrates an additive non-uniform random sampling and interrogation method for dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to generate non-equidistant space of a sensing pulse train in the time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A 1.9 kHz dynamic strain is measured by generating an additive non-uniform randomly distributed 2 kHz optical sensing pulse train from a mean 500 Hz triangular periodically changing scanning frequency. (paper)

  6. Additive non-uniform random sampling in superimposed fiber Bragg grating strain gauge

    Science.gov (United States)

    Ma, Y. C.; Liu, H. Y.; Yan, S. B.; Yang, Y. H.; Yang, M. W.; Li, J. M.; Tang, J.

    2013-05-01

    This paper demonstrates an additive non-uniform random sampling and interrogation method for dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to generate non-equidistant space of a sensing pulse train in the time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A 1.9 kHz dynamic strain is measured by generating an additive non-uniform randomly distributed 2 kHz optical sensing pulse train from a mean 500 Hz triangular periodically changing scanning frequency.

  7. Fixed-location hydroacoustic monitoring designs for estimating fish passage using stratified random and systematic sampling

    International Nuclear Information System (INIS)

    Skalski, J.R.; Hoffman, A.; Ransom, B.H.; Steig, T.W.

    1993-01-01

    Five alternate sampling designs are compared using 15 d of 24-h continuous hydroacoustic data to identify the most favorable approach to fixed-location hydroacoustic monitoring of salmonid outmigrants. Four alternative aproaches to systematic sampling are compared among themselves and with stratified random sampling (STRS). Stratifying systematic sampling (STSYS) on a daily basis is found to reduce sampling error in multiday monitoring studies. Although sampling precision was predictable with varying levels of effort in STRS, neither magnitude nor direction of change in precision was predictable when effort was varied in systematic sampling (SYS). Furthermore, modifying systematic sampling to include replicated (e.g., nested) sampling (RSYS) is further shown to provide unbiased point and variance estimates as does STRS. Numerous short sampling intervals (e.g., 12 samples of 1-min duration per hour) must be monitored hourly using RSYS to provide efficient, unbiased point and interval estimates. For equal levels of effort, STRS outperformed all variations of SYS examined. Parametric approaches to confidence interval estimates are found to be superior to nonparametric interval estimates (i.e., bootstrap and jackknife) in estimating total fish passage. 10 refs., 1 fig., 8 tabs

  8. Self-reference and random sampling approach for label-free identification of DNA composition using plasmonic nanomaterials.

    Science.gov (United States)

    Freeman, Lindsay M; Pang, Lin; Fainman, Yeshaiahu

    2018-05-09

    The analysis of DNA has led to revolutionary advancements in the fields of medical diagnostics, genomics, prenatal screening, and forensic science, with the global DNA testing market expected to reach revenues of USD 10.04 billion per year by 2020. However, the current methods for DNA analysis remain dependent on the necessity for fluorophores or conjugated proteins, leading to high costs associated with consumable materials and manual labor. Here, we demonstrate a potential label-free DNA composition detection method using surface-enhanced Raman spectroscopy (SERS) in which we identify the composition of cytosine and adenine within single strands of DNA. This approach depends on the fact that there is one phosphate backbone per nucleotide, which we use as a reference to compensate for systematic measurement variations. We utilize plasmonic nanomaterials with random Raman sampling to perform label-free detection of the nucleotide composition within DNA strands, generating a calibration curve from standard samples of DNA and demonstrating the capability of resolving the nucleotide composition. The work represents an innovative way for detection of the DNA composition within DNA strands without the necessity of attached labels, offering a highly sensitive and reproducible method that factors in random sampling to minimize error.

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

    Science.gov (United States)

    Yashchuk, Valeriy V.; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R.; Takacs, Peter Z.; Voronov, Dmitriy L.

    2011-09-01

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

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

    International Nuclear Information System (INIS)

    Yashchuk, Valeriy V.; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R.; Takacs, Peter Z.; Voronov, Dmitriy L.

    2011-01-01

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

  11. LOD score exclusion analyses for candidate genes using random population samples.

    Science.gov (United States)

    Deng, H W; Li, J; Recker, R R

    2001-05-01

    While extensive analyses have been conducted to test for, no formal analyses have been conducted to test against, the importance of candidate genes with random population samples. We develop a LOD score approach for exclusion analyses of candidate genes with random population samples. Under this approach, specific genetic effects and inheritance models at candidate genes can be analysed and if a LOD score is < or = - 2.0, the locus can be excluded from having an effect larger than that specified. Computer simulations show that, with sample sizes often employed in association studies, this approach has high power to exclude a gene from having moderate genetic effects. In contrast to regular association analyses, population admixture will not affect the robustness of our analyses; in fact, it renders our analyses more conservative and thus any significant exclusion result is robust. Our exclusion analysis complements association analysis for candidate genes in random population samples and is parallel to the exclusion mapping analyses that may be conducted in linkage analyses with pedigrees or relative pairs. The usefulness of the approach is demonstrated by an application to test the importance of vitamin D receptor and estrogen receptor genes underlying the differential risk to osteoporotic fractures.

  12. Path integral methods for primordial density perturbations - sampling of constrained Gaussian random fields

    International Nuclear Information System (INIS)

    Bertschinger, E.

    1987-01-01

    Path integrals may be used to describe the statistical properties of a random field such as the primordial density perturbation field. In this framework the probability distribution is given for a Gaussian random field subjected to constraints such as the presence of a protovoid or supercluster at a specific location in the initial conditions. An algorithm has been constructed for generating samples of a constrained Gaussian random field on a lattice using Monte Carlo techniques. The method makes possible a systematic study of the density field around peaks or other constrained regions in the biased galaxy formation scenario, and it is effective for generating initial conditions for N-body simulations with rare objects in the computational volume. 21 references

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

    Science.gov (United States)

    Sztepanacz, Jacqueline L; Blows, Mark W

    2017-07-01

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

  14. A simple and efficient alternative to implementing systematic random sampling in stereological designs without a motorized microscope stage.

    Science.gov (United States)

    Melvin, Neal R; Poda, Daniel; Sutherland, Robert J

    2007-10-01

    When properly applied, stereology is a very robust and efficient method to quantify a variety of parameters from biological material. A common sampling strategy in stereology is systematic random sampling, which involves choosing a random sampling [corrected] start point outside the structure of interest, and sampling relevant objects at [corrected] sites that are placed at pre-determined, equidistant intervals. This has proven to be a very efficient sampling strategy, and is used widely in stereological designs. At the microscopic level, this is most often achieved through the use of a motorized stage that facilitates the systematic random stepping across the structure of interest. Here, we report a simple, precise and cost-effective software-based alternative to accomplishing systematic random sampling under the microscope. We believe that this approach will facilitate the use of stereological designs that employ systematic random sampling in laboratories that lack the resources to acquire costly, fully automated systems.

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Iterative algorithm of discrete Fourier transform for processing randomly sampled NMR data sets

    International Nuclear Information System (INIS)

    Stanek, Jan; Kozminski, Wiktor

    2010-01-01

    Spectra obtained by application of multidimensional Fourier Transformation (MFT) to sparsely sampled nD NMR signals are usually corrupted due to missing data. In the present paper this phenomenon is investigated on simulations and experiments. An effective iterative algorithm for artifact suppression for sparse on-grid NMR data sets is discussed in detail. It includes automated peak recognition based on statistical methods. The results enable one to study NMR spectra of high dynamic range of peak intensities preserving benefits of random sampling, namely the superior resolution in indirectly measured dimensions. Experimental examples include 3D 15 N- and 13 C-edited NOESY-HSQC spectra of human ubiquitin.

  17. Randomized branch sampling to estimatefruit production in Pecan trees cv. ‘Barton’

    Directory of Open Access Journals (Sweden)

    Filemom Manoel Mokochinski

    Full Text Available ABSTRACT: Sampling techniques to quantify the production of fruits are still very scarce and create a gap in crop development research. This study was conducted in a rural property in the county of Cachoeira do Sul - RS to estimate the efficiency of randomized branch sampling (RBS in quantifying the production of pecan fruit at three different ages (5,7 and 10 years. Two selection techniques were tested: the probability proportional to the diameter (PPD and the uniform probability (UP techniques, which were performed on nine trees, three from each age and randomly chosen. The RBS underestimated fruit production for all ages, and its main drawback was the high sampling error (125.17% - PPD and 111.04% - UP. The UP was regarded as more efficient than the PPD, though both techniques estimated similar production and similar experimental errors. In conclusion, we reported that branch sampling was inaccurate for this case study, requiring new studies to produce estimates with smaller sampling error.

  18. Assessment of Different Sampling Methods for Measuring and Representing Macular Cone Density Using Flood-Illuminated Adaptive Optics.

    Science.gov (United States)

    Feng, Shu; Gale, Michael J; Fay, Jonathan D; Faridi, Ambar; Titus, Hope E; Garg, Anupam K; Michaels, Keith V; Erker, Laura R; Peters, Dawn; Smith, Travis B; Pennesi, Mark E

    2015-09-01

    To describe a standardized flood-illuminated adaptive optics (AO) imaging protocol suitable for the clinical setting and to assess sampling methods for measuring cone density. Cone density was calculated following three measurement protocols: 50 × 50-μm sampling window values every 0.5° along the horizontal and vertical meridians (fixed-interval method), the mean density of expanding 0.5°-wide arcuate areas in the nasal, temporal, superior, and inferior quadrants (arcuate mean method), and the peak cone density of a 50 × 50-μm sampling window within expanding arcuate areas near the meridian (peak density method). Repeated imaging was performed in nine subjects to determine intersession repeatability of cone density. Cone density montages could be created for 67 of the 74 subjects. Image quality was determined to be adequate for automated cone counting for 35 (52%) of the 67 subjects. We found that cone density varied with different sampling methods and regions tested. In the nasal and temporal quadrants, peak density most closely resembled histological data, whereas the arcuate mean and fixed-interval methods tended to underestimate the density compared with histological data. However, in the inferior and superior quadrants, arcuate mean and fixed-interval methods most closely matched histological data, whereas the peak density method overestimated cone density compared with histological data. Intersession repeatability testing showed that repeatability was greatest when sampling by arcuate mean and lowest when sampling by fixed interval. We show that different methods of sampling can significantly affect cone density measurements. Therefore, care must be taken when interpreting cone density results, even in a normal population.

  19. Revisiting random walk based sampling in networks: evasion of burn-in period and frequent regenerations.

    Science.gov (United States)

    Avrachenkov, Konstantin; Borkar, Vivek S; Kadavankandy, Arun; Sreedharan, Jithin K

    2018-01-01

    In the framework of network sampling, random walk (RW) based estimation techniques provide many pragmatic solutions while uncovering the unknown network as little as possible. Despite several theoretical advances in this area, RW based sampling techniques usually make a strong assumption that the samples are in stationary regime, and hence are impelled to leave out the samples collected during the burn-in period. This work proposes two sampling schemes without burn-in time constraint to estimate the average of an arbitrary function defined on the network nodes, for example, the average age of users in a social network. The central idea of the algorithms lies in exploiting regeneration of RWs at revisits to an aggregated super-node or to a set of nodes, and in strategies to enhance the frequency of such regenerations either by contracting the graph or by making the hitting set larger. Our first algorithm, which is based on reinforcement learning (RL), uses stochastic approximation to derive an estimator. This method can be seen as intermediate between purely stochastic Markov chain Monte Carlo iterations and deterministic relative value iterations. The second algorithm, which we call the Ratio with Tours (RT)-estimator, is a modified form of respondent-driven sampling (RDS) that accommodates the idea of regeneration. We study the methods via simulations on real networks. We observe that the trajectories of RL-estimator are much more stable than those of standard random walk based estimation procedures, and its error performance is comparable to that of respondent-driven sampling (RDS) which has a smaller asymptotic variance than many other estimators. Simulation studies also show that the mean squared error of RT-estimator decays much faster than that of RDS with time. The newly developed RW based estimators (RL- and RT-estimators) allow to avoid burn-in period, provide better control of stability along the sample path, and overall reduce the estimation time. Our

  20. Religiousness and headache: is there a relation? Results from a representative sample of adults living in a low-income community.

    Science.gov (United States)

    Lucchetti, Giancarlo; Lucchetti, Alessandra L G; Peres, Mario F Prieto

    2015-03-01

    The use of religious behaviors to alleviate the consequences of stressful life circumstances is a frequent strategy employed by pain sufferers. Specifically in the field of headache research, to date, few studies have assessed spiritual and religious beliefs. The objective of this article is to investigate the relation between religiousness (organizational, non-organizational and intrinsic) and headache disorders in a representative sample of adults living in a low-income community. This was a cross-sectional, population-based study. In 2005, we conducted door-to-door interviews with 439 people, aged more than 18 years, randomly selected from a low-income community in Brazil. Four regression models were created to explain the relationships between religious involvement and headache, controlling for demographics, depression/anxiety and alcohol use and smoking. Of the 439 households contacted, at least one member from 383 (87.2%) households participated. We interviewed more women (74.4%) and more subjects aged 18-39 years. The mean age was 41.7 (SD 8.5) years. Bivariate analysis shows that high religious attendance, non-organizational religiousness and intrinsic religiousness were associated with presence of headache and presence of migraine. After the logistic regression models, only high non-organizational religiousness remained associated with presence of headache (odds ratio (OR): 1.22 (1.01-1.49)). All other religious variables were unrelated to the presence of headache and its types. There is a modest relationship between high non-organizational religiousness and presence of headache. Headache sufferers may use coping strategies such as private religious behaviors to try to overcome suffering. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  1. An ultra-short screening version of the Recalled Parental Rearing Behavior questionnaire (FEE-US and its factor structure in a representative German sample

    Directory of Open Access Journals (Sweden)

    Petrowski Katja

    2012-11-01

    Full Text Available Abstract Background The Recalled Parental Rearing Behavior questionnaire (FEE, [1,2] assesses perceived parental rearing behavior separately for each parent. An ultra-short screening version (FEE-US with the same three scales each for the mother and the father is reported and factor-analytically validated. Methods N = 4,640 subjects aged 14 to 92 (M = 48.4 years were selected by the random-route sampling method. The ultra-short questionnaire version was derived from the long version through item and factor analyses. In a confirmatory factor analysis framework, the hypothesized three-factorial structure was fitted to the empirical data and tested for measurement invariance, differential item functioning, item discriminability, and convergent and discriminant factorial validity. Effects of gender or age were assessed using MANOVAs. Results The a-priori hypothesized model resulted in mostly adequate overall fit. Neither gender nor age group yielded considerable effects on the factor structure, but had small effects on means of raw score sums. Factorial validities could be confirmed. Scale sums are well-suited to rank respondents along the respective latent dimension. Conclusion The structure of the long version with the factors Rejection & Punishment, Emotional Warmth, and Control & Overprotection could be replicated for both father and mother items in the ultra-short screening version using confirmatory factor analyses. These results indicate that the ultra-short screening version is a time-saving and promising screening instrument for research settings and in individual counseling. However, the shortened scales do not necessarily represent the full spectrum covered by the full-scale dimensions.

  2. An individual urinary proteome analysis in normal human beings to define the minimal sample number to represent the normal urinary proteome

    Directory of Open Access Journals (Sweden)

    Liu Xuejiao

    2012-11-01

    Full Text Available Abstract Background The urinary proteome has been widely used for biomarker discovery. A urinary proteome database from normal humans can provide a background for discovery proteomics and candidate proteins/peptides for targeted proteomics. Therefore, it is necessary to define the minimum number of individuals required for sampling to represent the normal urinary proteome. Methods In this study, inter-individual and inter-gender variations of urinary proteome were taken into consideration to achieve a representative database. An individual analysis was performed on overnight urine samples from 20 normal volunteers (10 males and 10 females by 1DLC/MS/MS. To obtain a representative result of each sample, a replicate 1DLCMS/MS analysis was performed. The minimal sample number was estimated by statistical analysis. Results For qualitative analysis, less than 5% of new proteins/peptides were identified in a male/female normal group by adding a new sample when the sample number exceeded nine. In addition, in a normal group, the percentage of newly identified proteins/peptides was less than 5% upon adding a new sample when the sample number reached 10. Furthermore, a statistical analysis indicated that urinary proteomes from normal males and females showed different patterns. For quantitative analysis, the variation of protein abundance was defined by spectrum count and western blotting methods. And then the minimal sample number for quantitative proteomic analysis was identified. Conclusions For qualitative analysis, when considering the inter-individual and inter-gender variations, the minimum sample number is 10 and requires a balanced number of males and females in order to obtain a representative normal human urinary proteome. For quantitative analysis, the minimal sample number is much greater than that for qualitative analysis and depends on the experimental methods used for quantification.

  3. Improving ambulatory saliva-sampling compliance in pregnant women: a randomized controlled study.

    Directory of Open Access Journals (Sweden)

    Julian Moeller

    Full Text Available OBJECTIVE: Noncompliance with scheduled ambulatory saliva sampling is common and has been associated with biased cortisol estimates in nonpregnant subjects. This study is the first to investigate in pregnant women strategies to improve ambulatory saliva-sampling compliance, and the association between sampling noncompliance and saliva cortisol estimates. METHODS: We instructed 64 pregnant women to collect eight scheduled saliva samples on two consecutive days each. Objective compliance with scheduled sampling times was assessed with a Medication Event Monitoring System and self-reported compliance with a paper-and-pencil diary. In a randomized controlled study, we estimated whether a disclosure intervention (informing women about objective compliance monitoring and a reminder intervention (use of acoustical reminders improved compliance. A mixed model analysis was used to estimate associations between women's objective compliance and their diurnal cortisol profiles, and between deviation from scheduled sampling and the cortisol concentration measured in the related sample. RESULTS: Self-reported compliance with a saliva-sampling protocol was 91%, and objective compliance was 70%. The disclosure intervention was associated with improved objective compliance (informed: 81%, noninformed: 60%, F(1,60  = 17.64, p<0.001, but not the reminder intervention (reminders: 68%, without reminders: 72%, F(1,60 = 0.78, p = 0.379. Furthermore, a woman's increased objective compliance was associated with a higher diurnal cortisol profile, F(2,64  = 8.22, p<0.001. Altered cortisol levels were observed in less objective compliant samples, F(1,705  = 7.38, p = 0.007, with delayed sampling associated with lower cortisol levels. CONCLUSIONS: The results suggest that in pregnant women, objective noncompliance with scheduled ambulatory saliva sampling is common and is associated with biased cortisol estimates. To improve sampling compliance, results suggest

  4. Representativeness of two sampling procedures for an internet intervention targeting cancer-related distress: a comparison of convenience and registry samples

    OpenAIRE

    Owen, Jason E.; Bantum, Erin O'Carroll; Criswell, Kevin; Bazzo, Julie; Gorlick, Amanda; Stanton, Annette L.

    2013-01-01

    Internet interventions often rely on convenience sampling, yet convenience samples may differ in important ways from systematic recruitment approaches. The purpose of this study was to evaluate potential demographic, medical, and psychosocial differences between Internet-recruited and registry-recruited cancer survivors in an Internet-based intervention. Participants were recruited from a cancer registry (n = 80) and via broad Internet outreach efforts (n = 160). Participants completed a set ...

  5. A Behavior-Genetic Study of Parenting Quality, Infant Attachment Security, and Their Covariation in a Nationally Representative Sample

    Science.gov (United States)

    Roisman, Glenn I.; Fraley, R. Chris

    2008-01-01

    A number of relatively small-sample, genetically sensitive studies of infant attachment security have been published in the past several years that challenge the view that all psychological phenotypes are heritable and that environmental influences on child development--to the extent that they can be detected--serve to make siblings dissimilar.…

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

    DEFF Research Database (Denmark)

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

    implementation generally improved the algorithm’s ability to predict the correct soil class. The implementation of soil-landscape relationships and area-proportional sampling generally increased the calculation time, while the random forest implementation reduced the calculation time. In the most successful......Detailed soil information is often needed to support agricultural practices, environmental protection and policy decisions. Several digital approaches can be used to map soil properties based on field observations. When soil observations are sparse or missing, an alternative approach...... is to disaggregate existing conventional soil maps. At present, the DSMART algorithm represents the most sophisticated approach for disaggregating conventional soil maps (Odgers et al., 2014). The algorithm relies on classification trees trained from resampled points, which are assigned classes according...

  7. Acute stress symptoms during the second Lebanon war in a random sample of Israeli citizens.

    Science.gov (United States)

    Cohen, Miri; Yahav, Rivka

    2008-02-01

    The aims of this study were to assess prevalence of acute stress disorder (ASD) and acute stress symptoms (ASS) in Israel during the second Lebanon war. A telephone survey was conducted in July 2006 of a random sample of 235 residents of northern Israel, who were subjected to missile attacks, and of central Israel, who were not subjected to missile attacks. Results indicate that ASS scores were higher in the northern respondents; 6.8% of the northern sample and 3.9% of the central sample met ASD criteria. Appearance of each symptom ranged from 15.4% for dissociative to 88.4% for reexperiencing, with significant differences between northern and central respondents only for reexperiencing and arousal. A low ASD rate and a moderate difference between areas subjected and not subjected to attack were found.

  8. How many EMA-workshops are needed to collect a representative sample of events in a hospital ward?

    DEFF Research Database (Denmark)

    Edwards, Kasper

    2017-01-01

    The effect modifier assessment (EMA) method (Edwards & Winkel, 2016) is a method for assessing the impact of an intervention and modifiers on a desired outcome e.g. improved work environment. The EMA-method captures events (a change in work) in a ward and for each event asses 1) impact on work...... and diverse tasks. This poses a problem when using the EMA-method and raises the research question of this abstract: How many EMA-workshops are needed to generate a representative collection of events in a ward? Methods Six EMA-workshops each with a full surgical team of six people was conducted in a heart...... on surgery. The ward was organized in three specialties: Heart surgery, Lung surgery and Child heart surgery. Events differed between specialties and therefor it was expected that saturation would be reached after minimum three workshops. The heart center is comparable to other surgical units...

  9. Sexual diversity in the United States: Results from a nationally representative probability sample of adult women and men.

    Directory of Open Access Journals (Sweden)

    Debby Herbenick

    Full Text Available In 2015, we conducted a cross-sectional, Internet-based, U.S. nationally representative probability survey of 2,021 adults (975 men, 1,046 women focused on a broad range of sexual behaviors. Individuals invited to participate were from the GfK KnowledgePanel®. The survey was titled the 2015 Sexual Exploration in America Study and survey completion took about 12 to 15 minutes. The survey was confidential and the researchers never had access to respondents' identifiers. Respondents reported on demographic items, lifetime and recent sexual behaviors, and the appeal of 50+ sexual behaviors. Most (>80% reported lifetime masturbation, vaginal sex, and oral sex. Lifetime anal sex was reported by 43% of men (insertive and 37% of women (receptive. Common lifetime sexual behaviors included wearing sexy lingerie/underwear (75% women, 26% men, sending/receiving digital nude/semi-nude photos (54% women, 65% men, reading erotic stories (57% of participants, public sex (≥43%, role-playing (≥22%, tying/being tied up (≥20%, spanking (≥30%, and watching sexually explicit videos/DVDs (60% women, 82% men. Having engaged in threesomes (10% women, 18% men and playful whipping (≥13% were less common. Lifetime group sex, sex parties, taking a sexuality class/workshop, and going to BDSM parties were uncommon (each <8%. More Americans identified behaviors as "appealing" than had engaged in them. Romantic/affectionate behaviors were among those most commonly identified as appealing for both men and women. The appeal of particular behaviors was associated with greater odds that the individual had ever engaged in the behavior. This study contributes to our understanding of more diverse adult sexual behaviors than has previously been captured in U.S. nationally representative probability surveys. Implications for sexuality educators, clinicians, and individuals in the general population are discussed.

  10. Sexual diversity in the United States: Results from a nationally representative probability sample of adult women and men

    Science.gov (United States)

    Herbenick, Debby; Bowling, Jessamyn; Fu, Tsung-Chieh (Jane); Guerra-Reyes, Lucia; Sanders, Stephanie

    2017-01-01

    In 2015, we conducted a cross-sectional, Internet-based, U.S. nationally representative probability survey of 2,021 adults (975 men, 1,046 women) focused on a broad range of sexual behaviors. Individuals invited to participate were from the GfK KnowledgePanel®. The survey was titled the 2015 Sexual Exploration in America Study and survey completion took about 12 to 15 minutes. The survey was confidential and the researchers never had access to respondents’ identifiers. Respondents reported on demographic items, lifetime and recent sexual behaviors, and the appeal of 50+ sexual behaviors. Most (>80%) reported lifetime masturbation, vaginal sex, and oral sex. Lifetime anal sex was reported by 43% of men (insertive) and 37% of women (receptive). Common lifetime sexual behaviors included wearing sexy lingerie/underwear (75% women, 26% men), sending/receiving digital nude/semi-nude photos (54% women, 65% men), reading erotic stories (57% of participants), public sex (≥43%), role-playing (≥22%), tying/being tied up (≥20%), spanking (≥30%), and watching sexually explicit videos/DVDs (60% women, 82% men). Having engaged in threesomes (10% women, 18% men) and playful whipping (≥13%) were less common. Lifetime group sex, sex parties, taking a sexuality class/workshop, and going to BDSM parties were uncommon (each <8%). More Americans identified behaviors as “appealing” than had engaged in them. Romantic/affectionate behaviors were among those most commonly identified as appealing for both men and women. The appeal of particular behaviors was associated with greater odds that the individual had ever engaged in the behavior. This study contributes to our understanding of more diverse adult sexual behaviors than has previously been captured in U.S. nationally representative probability surveys. Implications for sexuality educators, clinicians, and individuals in the general population are discussed. PMID:28727762

  11. Distributed fiber sparse-wideband vibration sensing by sub-Nyquist additive random sampling

    Science.gov (United States)

    Zhang, Jingdong; Zheng, Hua; Zhu, Tao; Yin, Guolu; Liu, Min; Bai, Yongzhong; Qu, Dingrong; Qiu, Feng; Huang, Xianbing

    2018-05-01

    The round trip time of the light pulse limits the maximum detectable vibration frequency response range of phase-sensitive optical time domain reflectometry ({\\phi}-OTDR). Unlike the uniform laser pulse interval in conventional {\\phi}-OTDR, we randomly modulate the pulse interval, so that an equivalent sub-Nyquist additive random sampling (sNARS) is realized for every sensing point of the long interrogation fiber. For an {\\phi}-OTDR system with 10 km sensing length, the sNARS method is optimized by theoretical analysis and Monte Carlo simulation, and the experimental results verify that a wide-band spars signal can be identified and reconstructed. Such a method can broaden the vibration frequency response range of {\\phi}-OTDR, which is of great significance in sparse-wideband-frequency vibration signal detection, such as rail track monitoring and metal defect detection.

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

    Directory of Open Access Journals (Sweden)

    Alireza Goli

    2015-09-01

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

  13. Random On-Board Pixel Sampling (ROPS) X-Ray Camera

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui [Los Alamos; Iaroshenko, O. [Los Alamos; Li, S. [Los Alamos; Liu, T. [Fermilab; Parab, N. [Argonne (main); Chen, W. W. [Purdue U.; Chu, P. [Los Alamos; Kenyon, G. [Los Alamos; Lipton, R. [Fermilab; Sun, K.-X. [Nevada U., Las Vegas

    2017-09-25

    Recent advances in compressed sensing theory and algorithms offer new possibilities for high-speed X-ray camera design. In many CMOS cameras, each pixel has an independent on-board circuit that includes an amplifier, noise rejection, signal shaper, an analog-to-digital converter (ADC), and optional in-pixel storage. When X-ray images are sparse, i.e., when one of the following cases is true: (a.) The number of pixels with true X-ray hits is much smaller than the total number of pixels; (b.) The X-ray information is redundant; or (c.) Some prior knowledge about the X-ray images exists, sparse sampling may be allowed. Here we first illustrate the feasibility of random on-board pixel sampling (ROPS) using an existing set of X-ray images, followed by a discussion about signal to noise as a function of pixel size. Next, we describe a possible circuit architecture to achieve random pixel access and in-pixel storage. The combination of a multilayer architecture, sparse on-chip sampling, and computational image techniques, is expected to facilitate the development and applications of high-speed X-ray camera technology.

  14. Microfinance Participation, Control Over Resources, and Justification of IPV: Results From a Nationally Representative Sample of Women.

    Science.gov (United States)

    Murshid, Nadine Shaanta

    2016-04-13

    A high percentage of men and women are purported to justify intimate partner violence (IPV) in countries that are steeped in patriarchy even in the presence of programs such as microfinance that aim to address gender equity. This article examines two assertions that emerge from the literature on microfinance and its potential for positive outcomes for women who participate in it: (a) Microfinance participation is associated with reduced justification of IPV, and (b) microfinance participants with control over their own resources are less likely to justify IPV when compared with microfinance participants who do not have control over their resources. Couples data from a nationally representative survey, the Bangladesh Demographic and Health Survey, were used in the present study. Propensity score matching and logistic regression analyses were conducted to reveal that (a) microfinance participation was not associated with justification of IPV and that (b) women who participated in microfinance were less likely to justify IPV when they had no control over their resources. Implications for practitioners and policymakers are discussed. © The Author(s) 2016.

  15. Spectrum of dizziness visits to US emergency departments: cross-sectional analysis from a nationally representative sample.

    Science.gov (United States)

    Newman-Toker, David E; Hsieh, Yu-Hsiang; Camargo, Carlos A; Pelletier, Andrea J; Butchy, Gregary T; Edlow, Jonathan A

    2008-07-01

    To describe the spectrum of visits to US emergency departments (EDs) for acute dizziness and determine whether ED patients with dizziness are diagnosed as having a range of benign and dangerous medical disorders, rather than predominantly vestibular ones. A cross-sectional study of ED visits from the National Hospital Ambulatory Medical Care Survey (NHAMCS) used a weighted sample of US ED visits (1993-2005) to measure patient and hospital demographics, ED diagnoses, and resource use in cases vs controls without dizziness. Dizziness in patients 16 years or older was defined as an NHAMCS reason-for-visit code of dizziness/vertigo (1225.0) or a final International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis of dizziness/vertigo (780.4) or of a vestibular disorder (386.x). A total of 9472 dizziness cases (3.3% of visits) were sampled over 13 years (weighted 33.6 million). Top diagnostic groups were otologic/vestibular (32.9%), cardiovascular (21.1%), respiratory (11.5%), neurologic (11.2%, including 4% cerebrovascular), metabolic (11.0%), injury/poisoning (10.6%), psychiatric (7.2%), digestive (7.0%), genitourinary (5.1%), and infectious (2.9%). Nearly half of the cases (49.2%) were given a medical diagnosis, and 22.1% were given only a symptom diagnosis. Predefined dangerous disorders were diagnosed in 15%, especially among those older than 50 years (20.9% vs 9.3%; Pdisorder in most ED cases and often is associated with cardiovascular or other medical causes, including dangerous ones. Resource use is substantial, yet many patients remain undiagnosed.

  16. MUP, CEC-DES, STRADE. Codes for uncertainty propagation, experimental design and stratified random sampling techniques

    International Nuclear Information System (INIS)

    Amendola, A.; Astolfi, M.; Lisanti, B.

    1983-01-01

    The report describes the how-to-use of the codes: MUP (Monte Carlo Uncertainty Propagation) for uncertainty analysis by Monte Carlo simulation, including correlation analysis, extreme value identification and study of selected ranges of the variable space; CEC-DES (Central Composite Design) for building experimental matrices according to the requirements of Central Composite and Factorial Experimental Designs; and, STRADE (Stratified Random Design) for experimental designs based on the Latin Hypercube Sampling Techniques. Application fields, of the codes are probabilistic risk assessment, experimental design, sensitivity analysis and system identification problems

  17. Neighborhood age structure and cognitive function in a nationally-representative sample of older adults in the U.S.

    Science.gov (United States)

    Friedman, Esther M; Shih, Regina A; Slaughter, Mary E; Weden, Margaret M; Cagney, Kathleen A

    2017-02-01

    Recent evidence suggests that living in a neighborhood with a greater percentage of older adults is associated with better individual health, including lower depression, better self-rated health, and a decreased risk of overall mortality. However, much of the work to date suffers from four limitations. First, none of the U.S.-based studies examine the association at the national level. Second, no studies have examined three important hypothesized mechanisms - neighborhood socioeconomic status and neighborhood social and physical characteristics - which are significantly correlated with both neighborhood age structure and health. Third, no U.S. study has longitudinally examined cognitive health trajectories. We build on this literature by examining nine years of nationally-representative data from the Health and Retirement Study (2002-2010) on men and women aged 51 and over linked with Census data to examine the relationship between the percentage of adults 65 and older in a neighborhood and individual cognitive health trajectories. Our results indicate that living in a neighborhood with a greater percentage of older adults is related to better individual cognition at baseline but we did not find any significant association with cognitive decline. We also explored potential mediators including neighborhood socioeconomic status, perceived neighborhood cohesion and perceived neighborhood physical disorder. We did not find evidence that neighborhood socioeconomic status explains this relationship; however, there is suggestive evidence that perceived cohesion and disorder may explain some of the association between age structure and cognition. Although more work is needed to identify the precise mechanisms, this work may suggest a potential contextual target for public health interventions to prevent cognitive impairment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Intellectual disability is associated with increased risk for obesity in a nationally representative sample of U.S. children.

    Science.gov (United States)

    Segal, Mary; Eliasziw, Misha; Phillips, Sarah; Bandini, Linda; Curtin, Carol; Kral, Tanja V E; Sherwood, Nancy E; Sikich, Lin; Stanish, Heidi; Must, Aviva

    2016-07-01

    Data on obesity prevalence in children with intellectual disability (ID) are scarce. We estimated rates of obesity among children aged 10-17 years with and without ID in a nationally representative dataset that included measures of child weight and ID status, as well as family meal frequency, physical activity, and sedentary behavior. Chi-square tests compared prevalence of obesity, demographic and behavioral characteristics between children with and without ID as reported in the 2011 National Survey of Children's Health. Tests for interaction in logistic regression models determined whether associations between obesity and behavioral characteristics were different between children with/without ID. Obesity prevalence for children with ID was 28.9% and 15.5% for children without ID. After adjusting for age, sex, race/ethnicity and poverty level, the odds ratio was significantly 1.89 times greater among children with ID than among those without ID (95% CI: 1.14 to 3.12). Among children with ID, 49.8% ate at least one meal with family members every day compared to 35.0% without ID (p obesity was higher among all children who ate family meals every day compared to fewer days per week, and the effect was significantly more pronounced among those with ID (p = 0.05). Prevalence of obesity among youth with ID was almost double that of the general population. Prospective studies are needed in this population to examine the impact of consistent family mealtimes and infrequent physical activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The association between hypertension and depression and anxiety disorders: results from a nationally-representative sample of South African adults.

    Directory of Open Access Journals (Sweden)

    Anna Grimsrud

    Full Text Available Growing evidence suggests high levels of comorbidity between hypertension and mental illness but there are few data from low- and middle-income countries. We examined the association between hypertension and depression and anxiety in South Africa.Data come from a nationally-representative survey of adults (n = 4351. The Composite International Diagnostic Interview was used to measure DSM-IV mental disorders during the previous 12-months. The relationships between self-reported hypertension and anxiety disorders, depressive disorders and comorbid anxiety-depression were assessed after adjustment for participant characteristics including experience of trauma and other chronic physical conditions.Overall 16.7% reported a previous medical diagnosis of hypertension, and 8.1% and 4.9% were found to have a 12-month anxiety or depressive disorder, respectively. In adjusted analyses, hypertension diagnosis was associated with 12-month anxiety disorders [Odds ratio (OR = 1.55, 95% Confidence interval (CI = 1.10-2.18] but not 12-month depressive disorders or 12-month comorbid anxiety-depression. Hypertension in the absence of other chronic physical conditions was not associated with any of the 12-month mental health outcomes (p-values all <0.05, while being diagnosed with both hypertension and another chronic physical condition were associated with 12-month anxiety disorders (OR = 2.25, 95% CI = 1.46-3.45, but not 12-month depressive disorders or comorbid anxiety-depression.These are the first population-based estimates to demonstrate an association between hypertension and mental disorders in sub-Saharan Africa. Further investigation is needed into role of traumatic life events in the aetiology of hypertension as well as the temporality of the association between hypertension and mental disorders.

  20. Investigating Correlates of Self-Regulation in Early Childhood with a Representative Sample of English-Speaking American Families.

    Science.gov (United States)

    Piotrowski, Jessica Taylor; Lapierre, Matthew A; Linebarger, Deborah L

    2013-04-01

    Children who possess less self-regulatory skill are at a disadvantage when compared to children who demonstrate greater skill at regulating their emotions, cognitions and behavior. Children with these regulatory deficits have difficulty connecting with peers, generating relationships with teachers, negotiating their social world, and succeeding academically. By understanding the correlates of self-regulatory abilities, interventions can be developed to ensure that children at-risk for poor self-regulation receive the support necessary to enhance their regulatory skills. Using data from a nationally representative survey of English-speaking American parents with children between the ages of two and eight ( n  = 1,141), we evaluated a host of demographic and parenting variables to isolate the correlates of self-regulation. Older children were found to have fewer regulatory problems than younger children while children from low-income homes and male children were found to have greater problems with self-regulation. Minority status, household composition (single vs multi-parent), and parental education were not significant correlates of self-regulation. Findings also illustrate the powerful relationship between parenting style and self-regulation. Parents who rely on nurturing parenting practices that reinforce the child's sense of autonomy while still maintaining a consistent parenting presence (i.e., authoritative parenting) have children who demonstrate stronger self-regulatory skills. Parents who exert an excess of parental control (i.e., authoritarian parents) have children with weaker self-regulatory skills. And lastly, parents who have notable absence of control (i.e., permissive parents) are more likely to have children with considerable regulatory deficits. Results offer implications for both practitioners and scholars.

  1. Association of Physical Activity with Alcohol Abuse and Dependence in a Nationally-Representative U.S. Sample.

    Science.gov (United States)

    Damian, April Joy; Mendelson, Tamar

    2017-11-10

    Alcohol use is a pervasive and costly public health problem in the United States. Relapse rates from alcohol use disorders are high. Although exercise has been proposed as a strategy to prevent relapse, lifestyle modification is the least studied aspect of relapse prevention programs, especially among racial/ethnic minority populations. The current study assessed whether being physically active was associated with remission from alcohol abuse or dependence among Black (African American and Afro Caribbean) adults in the U.S. We utilized data on Black adult participants (n = 4,828) from the nationally representative National Survey of American Life (NSAL) conducted in 2001-2003. Logistic regression models were estimated to assess the odds of being in 12-month remission or currently meeting DSM-IV criteria for alcohol abuse or dependence based on level of physical activity, adjusting for socio-demographic and neighborhood characteristics. People who endorsed being physically active had higher odds of being in 12-month remission from alcohol use problems (OR: 1.67, 95% CI: 1.28, 2.17) than people who were physically inactive, adjusting for individual- and neighborhood-level characteristics. People who were physically active did not differ significantly from those who were inactive with respect to odds of currently meeting DSM-IV criteria for alcohol abuse or dependence. Conclusions/Importance: Physical activity was positively associated with being in 12-month remission from alcohol use problems. Longitudinal studies are needed to establish temporal ordering and to explore exercise as a potential relapse prevention strategy for alcohol use problems.

  2. Diet- and Body Size-related Attitudes and Behaviors Associated with Vitamin Supplement Use in a Representative Sample of Fourth-grade Students in Texas

    Science.gov (United States)

    The objective of this research was to examine diet- and body size-related attitudes and behaviors associated with supplement use in a representative sample of fourth-grade students in Texas. The research design consisted of cross-sectional data from the School Physical Activity and Nutrition study, ...

  3. Exploring the Relation between Prenatal and Neonatal Complications and Later Autistic-Like Features in a Representative Community Sample of Twins

    Science.gov (United States)

    Ronald, Angelica; Happe, Francesca; Dworzynski, Katharina; Bolton, Patrick; Plomin, Robert

    2010-01-01

    Prenatal and neonatal events were reported by parents of 13,690 eighteen-month-old twins enrolled in the Twins Early Development Study, a representative community sample born in England and Wales. At ages 7-8, parents and teachers completed questionnaires on social and nonsocial autistic-like features and parents completed the Childhood Asperger…

  4. Short version of the Zimbardo Time Perspective Inventory (ZTPI-short) with and without the Future-Negative scale, verified on nationally representative samples

    Czech Academy of Sciences Publication Activity Database

    Košťál, Jaroslav; Klicperová-Baker, Martina; Lukavská, K.; Lukavský, Jiří

    2016-01-01

    Roč. 25, č. 2 (2016), s. 169-192 ISSN 0961-463X Institutional support: RVO:68081740 Keywords : ZTPI * ZTPI-short * time perspective * temporal orientation * representative sample Subject RIV: AN - Psychology Impact factor: 1.206, year: 2016

  5. Validation of a 16-Item Short Form of the Czech Version of the Experiences in Close Relationships Revised Questionnaire in a Representative Sample

    Czech Academy of Sciences Publication Activity Database

    Kaščáková, N.; Husárová, D.; Hašto, J.; Kolarčik, P.; Poláčková Šolcová, Iva; Madarasová Gecková, A.; Tavel, P.

    2016-01-01

    Roč. 119, č. 3 (2016), s. 804-825 ISSN 0033-2941 Institutional support: RVO:68081740 Keywords : Short form of the ECR-R * Experiences in Close Relationships Revised Questionnaire * validation * attachment anxiety * attachment avoidance * attachment styles * representative sample Subject RIV: AN - Psychology Impact factor: 0.629, year: 2016

  6. Depressive symptoms and indoor tanning among U.S. Hispanic adolescents: Results from a nationally representative sample.

    Science.gov (United States)

    Gonzales, Manuel; Blashill, Aaron J

    2018-01-01

    To examine the association between depressive symptoms and indoor tanning among U.S. Hispanic adolescents. Data were collected from the 2015 Youth Risk Behavior Survey (YRBS). In the current study, only Hispanic adolescents were included, which yielded a total weighted sample of 2,667 (men: N = 1,368; women: N = 1,299). Gender was also explored as a moderator in the association between depressive symptoms (sadness or hopelessness and suicidality) and indoor tanning. Logistic regressions were used, with past 12 month indoor tanning behavior (0 vs. 1 or more sessions) entered as the dependent variable. Across gender, sadness or hopelessness was associated with increased odds of indoor tanning (OR = 1.8, 95% CI [1.2, 3.0], p = .01); however, gender significantly moderated the association between suicidality and indoor tanning. Simple slope analyses revealed that suicidality was significantly associated with increased odds of indoor tanning only among boys (OR = 4.0, 95% CI [2.1, 7.5], p = .001) whereas a nonsignificant association was found among girls (OR = 0.8, 95% CI [0.4, 1.8], p = .65). Results suggest there is a differential relationship between suicidality and indoor tanning as function of gender among U.S. Hispanic adolescents. Skin cancer prevention programs for Hispanic youth may wish to consider the role of gender and negative affect in targeted campaigns. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  7. Assessment of Disability among the Elderly in Xiamen of China: A Representative Sample Survey of 14,292 Older Adults.

    Directory of Open Access Journals (Sweden)

    Wei Chen

    Full Text Available The unprecedented number of elderly individuals in China presents a serious public health challenge. Limited data are available on the prevalence of disability or factors resulting in disability among the elderly in China.We aimed to assess the prevalence of disability and related risk factors among the elderly of Xiamen, China.A cross-sectional study was performed on individuals who were ≥60 years of age. The subjects were recruited by multi-stage sampling; a total of 14,292 valid questionnaires were received. Study measurements included activities of daily living (ADL, demographics, and health status. The ADL was assessed by the Katz Index Scale to evaluate disability. Chi-square tests and binary logistic regression were used to identify factors associated with disabilities.Among the valid participants, 4.27% had at least one disability. Bathing was the most frequently reported disability and feeding was the least frequently reported disability. Disabilities were significantly associated with female gender, older age, unmarried status, living with family, urban residence, illiteracy, poor economic status, self-rated bad health, chronic illnesses, lower life satisfaction, bad mood, and feelings of loneliness.Functional disability among the elderly requires more public attention. Culturally appropriate policies and programs are also needed to address the care for the disabled elderly.

  8. Event-triggered synchronization for reaction-diffusion complex networks via random sampling

    Science.gov (United States)

    Dong, Tao; Wang, Aijuan; Zhu, Huiyun; Liao, Xiaofeng

    2018-04-01

    In this paper, the synchronization problem of the reaction-diffusion complex networks (RDCNs) with Dirichlet boundary conditions is considered, where the data is sampled randomly. An event-triggered controller based on the sampled data is proposed, which can reduce the number of controller and the communication load. Under this strategy, the synchronization problem of the diffusion complex network is equivalently converted to the stability of a of reaction-diffusion complex dynamical systems with time delay. By using the matrix inequality technique and Lyapunov method, the synchronization conditions of the RDCNs are derived, which are dependent on the diffusion term. Moreover, it is found the proposed control strategy can get rid of the Zeno behavior naturally. Finally, a numerical example is given to verify the obtained results.

  9. Quality issues of self-report of hypertension: analysis of a population representative sample of older adults in Taiwan.

    Science.gov (United States)

    Tsai, Alan Chung-Hong; Chang, Tsui-Lan

    2012-01-01

    The study was to evaluate the quality of self-report of hypertension and examine the factors associated with under- and over-reporting of hypertension in older Taiwanese. Data for this analysis were from the Social Environment and Biomarkers Study in Taiwan 2000, which involved a national sample of 1021 Taiwanese over 54 years of age. We performed binary classification tests to compare the prevalence rates of self-reported vs. clinically measured hypertension according to World Health Organization (WHO) (blood pressure ≥ 160/95 mm Hg or on hypertension medication) and JNC-6 (140/90 mm Hg or on hypertension medication) definitions. Logistic regression analysis was performed to analyze the potential factors associated with under- or over-reporting of blood pressure status. Results showed the test characteristics of self-reports were: sensitivity 73%, specificity 93%, and kappa = 0.68 (p WHO definition; and sensitivity 51%, specificity 95% and kappa = 0.43 (p definition. Old age was associated with over-reporting whereas having no health checkup during the past 12 months was associated with under-reporting. The relatively low agreement between self-reports and clinically measured hypertension (JNC-6 definition) was mainly due to the lack of a well-defined hypertension practice guideline and the failure of clinicians to clearly inform patients of their diagnoses. The consistency of hypertension practice guidelines and the effectiveness of informing the patients of their diagnoses are two main factors impacting the quality of self-report of hypertension in elderly Taiwanese. Better self-reports of health data can improve the efficiency of public health surveillance efforts. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Prevalence of dyslipidemia according to the nutritional status in a representative sample of São Paulo.

    Science.gov (United States)

    Garcez, Marcela Riccioppo; Pereira, Jaqueline Lopes; Fontanelli, Mariane de Mello; Marchioni, Dirce Maria Lobo; Fisberg, Regina Mara

    2014-12-01

    Overweight is one of the major public health problems in Brazil; it is associated with dyslipidemia, which is an important risk factor for cardiovascular diseases. To evaluate the lipid profile of residents of the municipality of São Paulo, state of São Paulo, according to the nutritional status. Data from the population-based cross-sectional study ISA-Capital 2008 on a sample of residents of São Paulo were used. Participants were categorized into groups according to body mass index and age range. The levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and non-HDL cholesterol were measured. The association between lipid profile, nutricional status, and waist circumference was investigated. The data were processed using the survey mode of the Stata 11.0 software. The prevalence of any type of dyslipidemia in the population was 59.74%, with low HDL-cholesterol dyslipidemia being the most common type. Not overweight individuals had higher mean levels of HDL-cholesterol and lower levels of LDL-cholesterol, total cholesterol, triglycerides, and non-HDL cholesterol when compared with the overweight group. The rate of inadequacy of these variables was higher in the overweight individuals, regardless of the age group, to the exception of LDL-cholesterol in the adults and elderly. A higher prevalence of isolated hypertriglyceridemia was observed in individuals with higher waist circumference among the adults and the total population. The results indicate an association between dyslipidemia and overweight in the population of the city of São Paulo. The most prevalent dyslipidemia in this population was low HDL-cholesterol.

  11. Racial/ethnic differences in 30-year trajectories of heavy drinking in a nationally representative U.S. sample.

    Science.gov (United States)

    Mulia, Nina; Karriker-Jaffe, Katherine J; Witbrodt, Jane; Bond, Jason; Williams, Edwina; Zemore, Sarah E

    2017-01-01

    Racial/ethnic minorities bear a disproportionate burden of alcohol-related problems in the U.S. It is unknown whether this reflects harmful patterns of lifecourse heavy drinking. Prior research shows little support for the latter but has been limited to young samples. We examine racial/ethnic differences in heavy drinking trajectories from ages 21 to 51. Data on heavy drinking (6+ drinks/occasion) are from the 1979 National Longitudinal Survey of Youth (N=9468), collected between 1982 and 2012. Sex-stratified, generalized estimating equations (GEE) were used to model heavy drinking frequency trajectories as a function of age with a cubic curve, and interactions of race with age terms were tested to assess racial/ethnic differences. Models adjusted for time-varying socioeconomic status and marital and parenting status; predictors of trajectories were examined in race- and sex-specific models. White men and women had similarly steep declines in heavy drinking frequency throughout the 20s, contrasting with slower declines (and lower peaks) in Black and Hispanic men and women. During the 30s there was a Hispanic-White crossover in men's heavy drinking curves, and a Black-White female crossover among lifetime heavy drinkers; by age 51, racial/ethnic group trajectories converged in both sexes. Greater education was protective for all groups. Observed racial/ethnic crossovers in heavy drinking frequency following young adulthood might contribute to disparities in alcohol-related problems in middle adulthood, and suggest a need for targeted interventions during this period. Additionally, interventions that increase educational attainment may constitute an important strategy for reducing heavy drinking in all groups. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Circulating Prostate-Specific Antigen and Telomere Length in a Nationally Representative Sample of Men Without History of Prostate Cancer.

    Science.gov (United States)

    Wulaningsih, Wahyu; Astuti, Yuliana; Matsuguchi, Tetsuya; Anggrandariyanny, Putri; Watkins, Johnathan

    2017-01-01

    We investigated the association of prostate-specific antigen (PSA) with leukocyte telomere length, which may be altered in preclinical prostate malignancies. This study was based on the 2001-2002 U.S. National Health and Nutrition Examination Survey (NHANES). A subsample of 1,127 men aged 40-85 years without prior history of prostate cancer who provided informed consent and blood samples were selected. Leukocyte telomere length (LTL) relative to standard DNA reference (T/S ratio) was quantified by polymerase chain reaction (PCR). Survey-weighted multivariable linear regression was performed to examine T/S ratio across quintiles of total and free PSA and free-to-total PSA ratio (%fPSA). A sensitivity analysis was performed by excluding men dying from prostate cancer during follow-up through to December 31, 2006. Stratification analyses were carried out to assess any effect modification by age group, race, body mass index (BMI), and levels of C-reactive protein (CRP), a marker of inflammation. Higher total PSA levels were associated to longer LTL, with approximately 8% increase in log-transformed T/S ratio (95% confidence interval [CI]: 2-13%) among men in the highest quintile of total PSA compared to the lowest in the fully adjusted model (P trend  = 0.01). No significant association was found for free PSA or %fPSA, although nonlinearity between all PSA measures and T/S ratio was indicated. Similar results were found after excluding men who died from prostate cancer during follow-up. We also found the associations between total PSA and T/S ratio to be strongest among non-Hispanic blacks, non-obese men (BMI specific mechanisms contributing to prostate cancer development. Prostate 77:22-32, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Femoral nerve block in a representative sample of elderly people with hip fracture: A randomised controlled trial.

    Science.gov (United States)

    Unneby, Anna; Svensson, Olle; Gustafson, Yngve; Olofsson, Birgitta

    2017-07-01

    The number of elderly people with hip fracture and dementia is increasing, and many of these patients suffer from pain. Opioids are difficult to adjust and side effects are common, especially with increased age and among patients with dementia. Preoperative femoral nerve block is an alternative pain treatment. To investigate whether preoperative femoral nerve block reduced acute pain and opioid use after hip fracture among elderly patients, including those with dementia. In this randomised controlled trial involving patients aged ≥70years with hip fracture (trochanteric and cervical), including those with dementia, we compared femoral nerve block with conventional pain management, with opioid use if required. The primary outcome was preoperative pain, measured at five timepoints using a visual analogue scale (VAS). Preoperative opioid consumption was also registered. The study sample comprised 266 patients admitted consecutively to the Orthopaedic Ward. The mean age was 84.1 (±6.9)years, 64% of participants were women, 44% lived in residential care facilities, and 120 (45.1%) had dementia diagnoses. Patients receiving femoral nerve block had significantly lower self-rated pain scores from baseline to 12h after admission than did controls. Self-rated and proxy VAS pain scores decreased significantly in these patients from baseline to 12h compared with controls (pblock required less opioids than did controls, overall (2.3±4.0 vs. 5.7±5.2mg, pblock had lower pain scores and required less opioids before surgery compared with those receiving conventional pain management. Femoral nerve block seems to be a feasible pain treatment for elderly people, including those with dementia. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Electronic cigarette use in the European Union: analysis of a representative sample of 27 460 Europeans from 28 countries.

    Science.gov (United States)

    Farsalinos, Konstantinos E; Poulas, Konstantinos; Voudris, Vassilis; Le Houezec, Jacques

    2016-11-01

    To assess prevalence of electronic cigarette (e-cigarette) use, reported changes in smoking status due to e-cigarette use and correlates of e-cigarette use in the European Union (EU) member states in 2014. Cross-sectional survey of EU citizens representative of the population (Special Eurobarometer 429). All 28 Member States of the EU. A total of 27 460 EU citizens aged ≥ 15 years (after excluding those who responded 'Do not know' to the questions about smoking status and e-cigarette use). Descriptive analysis [%, 95% confidence interval (CI)] of e-cigarette use prevalence (current use, past use and past experimentation) according to smoking status, self-reported changes in smoking status according to patterns of e-cigarette use and logistic regression analysis to examine correlates of e-cigarette use, especially socio-demographic factors and smoking status. Ever e-cigarette use was reported by 31.1% (95% CI = 30.0-32.2%) of current smokers, 10.8% (95% CI = 10.0-11.7%) of former smokers and 2.3% (95% CI = 2.1-2.6%) of never smokers. Past experimentation [7.2% (95% CI = 6.9-7.5%)] was more common than current [1.8% (95% CI = 1.6-1.9%)] and past use [2.6% (95% CI = 2.4-2.8%)]. Extrapolated to the whole population, approximately 48.5 million EU citizens were ever e-cigarette users, with 76.8% using nicotine-containing e-cigarettes. An estimated 6.1 and 9.2 million EU citizens had quit and reduced smoking with the help of e-cigarettes, respectively. Initiation with e-cigarettes was reported by 0.8% (95% CI = 0.6-0.9%) of participants who reported ever use of any tobacco-related product. Only 1.3% (95% CI = 1.1-1.5%) of never smokers used nicotine-containing e-cigarettes, with 0.09% (95% CI = 0.04-0.14%) reporting daily nicotine use. Smoking cessation with the help of e-cigarettes was reported by 35.1% (95% CI = 30.7-39.5%) of current e-cigarette users, while a further 32.2% (95% CI = 29.9-36.5%) reported smoking reduction. Being current

  15. Determination of Initial Conditions for the Safety Analysis by Random Sampling of Operating Parameters

    International Nuclear Information System (INIS)

    Jeong, Hae-Yong; Park, Moon-Ghu

    2015-01-01

    In most existing evaluation methodologies, which follow a conservative approach, the most conservative initial conditions are searched for each transient scenario through tremendous assessment for wide operating windows or limiting conditions for operation (LCO) allowed by the operating guidelines. In this procedure, a user effect could be involved and a remarkable time and human resources are consumed. In the present study, we investigated a more effective statistical method for the selection of the most conservative initial condition by the use of random sampling of operating parameters affecting the initial conditions. A method for the determination of initial conditions based on random sampling of plant design parameters is proposed. This method is expected to be applied for the selection of the most conservative initial plant conditions in the safety analysis using a conservative evaluation methodology. In the method, it is suggested that the initial conditions of reactor coolant flow rate, pressurizer level, pressurizer pressure, and SG level are adjusted by controlling the pump rated flow, setpoints of PLCS, PPCS, and FWCS, respectively. The proposed technique is expected to contribute to eliminate the human factors introduced in the conventional safety analysis procedure and also to reduce the human resources invested in the safety evaluation of nuclear power plants

  16. A systematic examination of a random sampling strategy for source apportionment calculations.

    Science.gov (United States)

    Andersson, August

    2011-12-15

    Estimating the relative contributions from multiple potential sources of a specific component in a mixed environmental matrix is a general challenge in diverse fields such as atmospheric, environmental and earth sciences. Perhaps the most common strategy for tackling such problems is by setting up a system of linear equations for the fractional influence of different sources. Even though an algebraic solution of this approach is possible for the common situation with N+1 sources and N source markers, such methodology introduces a bias, since it is implicitly assumed that the calculated fractions and the corresponding uncertainties are independent of the variability of the source distributions. Here, a random sampling (RS) strategy for accounting for such statistical bias is examined by investigating rationally designed synthetic data sets. This random sampling methodology is found to be robust and accurate with respect to reproducibility and predictability. This method is also compared to a numerical integration solution for a two-source situation where source variability also is included. A general observation from this examination is that the variability of the source profiles not only affects the calculated precision but also the mean/median source contributions. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Deng, Hong-Wen

    2003-11-01

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

  18. Landslide Susceptibility Assessment Using Frequency Ratio Technique with Iterative Random Sampling

    Directory of Open Access Journals (Sweden)

    Hyun-Joo Oh

    2017-01-01

    Full Text Available This paper assesses the performance of the landslide susceptibility analysis using frequency ratio (FR with an iterative random sampling. A pair of before-and-after digital aerial photographs with 50 cm spatial resolution was used to detect landslide occurrences in Yongin area, Korea. Iterative random sampling was run ten times in total and each time it was applied to the training and validation datasets. Thirteen landslide causative factors were derived from the topographic, soil, forest, and geological maps. The FR scores were calculated from the causative factors and training occurrences repeatedly ten times. The ten landslide susceptibility maps were obtained from the integration of causative factors that assigned FR scores. The landslide susceptibility maps were validated by using each validation dataset. The FR method achieved susceptibility accuracies from 89.48% to 93.21%. And the landslide susceptibility accuracy of the FR method is higher than 89%. Moreover, the ten times iterative FR modeling may contribute to a better understanding of a regularized relationship between the causative factors and landslide susceptibility. This makes it possible to incorporate knowledge-driven considerations of the causative factors into the landslide susceptibility analysis and also be extensively used to other areas.

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

    Directory of Open Access Journals (Sweden)

    Ying Yan

    2017-01-01

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

  20. Randomized comparison of vaginal self-sampling by standard vs. dry swabs for Human papillomavirus testing

    International Nuclear Information System (INIS)

    Eperon, Isabelle; Vassilakos, Pierre; Navarria, Isabelle; Menoud, Pierre-Alain; Gauthier, Aude; Pache, Jean-Claude; Boulvain, Michel; Untiet, Sarah; Petignat, Patrick

    2013-01-01

    To evaluate if human papillomavirus (HPV) self-sampling (Self-HPV) using a dry vaginal swab is a valid alternative for HPV testing. Women attending colposcopy clinic were recruited to collect two consecutive Self-HPV samples: a Self-HPV using a dry swab (S-DRY) and a Self-HPV using a standard wet transport medium (S-WET). These samples were analyzed for HPV using real time PCR (Roche Cobas). Participants were randomized to determine the order of the tests. Questionnaires assessing preferences and acceptability for both tests were conducted. Subsequently, women were invited for colposcopic examination; a physician collected a cervical sample (physician-sampling) with a broom-type device and placed it into a liquid-based cytology medium. Specimens were then processed for the production of cytology slides and a Hybrid Capture HPV DNA test (Qiagen) was performed from the residual liquid. Biopsies were performed if indicated. Unweighted kappa statistics (κ) and McNemar tests were used to measure the agreement among the sampling methods. A total of 120 women were randomized. Overall HPV prevalence was 68.7% (95% Confidence Interval (CI) 59.3–77.2) by S-WET, 54.4% (95% CI 44.8–63.9) by S-DRY and 53.8% (95% CI 43.8–63.7) by HC. Among paired samples (S-WET and S-DRY), the overall agreement was good (85.7%; 95% CI 77.8–91.6) and the κ was substantial (0.70; 95% CI 0.57-0.70). The proportion of positive type-specific HPV agreement was also good (77.3%; 95% CI 68.2-84.9). No differences in sensitivity for cervical intraepithelial neoplasia grade one (CIN1) or worse between the two Self-HPV tests were observed. Women reported the two Self-HPV tests as highly acceptable. Self-HPV using dry swab transfer does not appear to compromise specimen integrity. Further study in a large screening population is needed. ClinicalTrials.gov: http://clinicaltrials.gov/show/NCT01316120

  1. Smoothing the redshift distributions of random samples for the baryon acoustic oscillations: applications to the SDSS-III BOSS DR12 and QPM mock samples

    Science.gov (United States)

    Wang, Shao-Jiang; Guo, Qi; Cai, Rong-Gen

    2017-12-01

    We investigate the impact of different redshift distributions of random samples on the baryon acoustic oscillations (BAO) measurements of D_V(z)r_d^fid/r_d from the two-point correlation functions of galaxies in the Data Release 12 of the Baryon Oscillation Spectroscopic Survey (BOSS). Big surveys, such as BOSS, usually assign redshifts to the random samples by randomly drawing values from the measured redshift distributions of the data, which would necessarily introduce fiducial signals of fluctuations into the random samples, weakening the signals of BAO, if the cosmic variance cannot be ignored. We propose a smooth function of redshift distribution that fits the data well to populate the random galaxy samples. The resulting cosmological parameters match the input parameters of the mock catalogue very well. The significance of BAO signals has been improved by 0.33σ for a low-redshift sample and by 0.03σ for a constant-stellar-mass sample, though the absolute values do not change significantly. Given the precision of the measurements of current cosmological parameters, it would be appreciated for the future improvements on the measurements of galaxy clustering.

  2. Assessment of fracture risk: value of random population-based samples--the Geelong Osteoporosis Study.

    Science.gov (United States)

    Henry, M J; Pasco, J A; Seeman, E; Nicholson, G C; Sanders, K M; Kotowicz, M A

    2001-01-01

    Fracture risk is determined by bone mineral density (BMD). The T-score, a measure of fracture risk, is the position of an individual's BMD in relation to a reference range. The aim of this study was to determine the magnitude of change in the T-score when different sampling techniques were used to produce the reference range. Reference ranges were derived from three samples, drawn from the same region: (1) an age-stratified population-based random sample, (2) unselected volunteers, and (3) a selected healthy subset of the population-based sample with no diseases or drugs known to affect bone. T-scores were calculated using the three reference ranges for a cohort of women who had sustained a fracture and as a group had a low mean BMD (ages 35-72 yr; n = 484). For most comparisons, the T-scores for the fracture cohort were more negative using the population reference range. The difference in T-scores reached 1.0 SD. The proportion of the fracture cohort classified as having osteoporosis at the spine was 26, 14, and 23% when the population, volunteer, and healthy reference ranges were applied, respectively. The use of inappropriate reference ranges results in substantial changes to T-scores and may lead to inappropriate management.

  3. The Paternal Landscape along the Bight of Benin - Testing Regional Representativeness of West-African Population Samples Using Y-Chromosomal Markers.

    Directory of Open Access Journals (Sweden)

    Maarten H D Larmuseau

    Full Text Available Patterns of genetic variation in human populations across the African continent are still not well studied in comparison with Eurasia and America, despite the high genetic and cultural diversity among African populations. In population and forensic genetic studies a single sample is often used to represent a complete African region. In such a scenario, inappropriate sampling strategies and/or the use of local, isolated populations may bias interpretations and pose questions of representativeness at a macrogeographic-scale. The non-recombining region of the Y-chromosome (NRY has great potential to reveal the regional representation of a sample due to its powerful phylogeographic information content. An area poorly characterized for Y-chromosomal data is the West-African region along the Bight of Benin, despite its important history in the trans-Atlantic slave trade and its large number of ethnic groups, languages and lifestyles. In this study, Y-chromosomal haplotypes from four Beninese populations were determined and a global meta-analysis with available Y-SNP and Y-STR data from populations along the Bight of Benin and surrounding areas was performed. A thorough methodology was developed allowing comparison of population samples using Y-chromosomal lineage data based on different Y-SNP panels and phylogenies. Geographic proximity turned out to be the best predictor of genetic affinity between populations along the Bight of Benin. Nevertheless, based on Y-chromosomal data from the literature two population samples differed strongly from others from the same or neighbouring areas and are not regionally representative within large-scale studies. Furthermore, the analysis of the HapMap sample YRI of a Yoruban population from South-western Nigeria based on Y-SNPs and Y-STR data showed for the first time its regional representativeness, a result which is important for standard population and forensic genetic applications using the YRI sample

  4. Accounting for randomness in measurement and sampling in studying cancer cell population dynamics.

    Science.gov (United States)

    Ghavami, Siavash; Wolkenhauer, Olaf; Lahouti, Farshad; Ullah, Mukhtar; Linnebacher, Michael

    2014-10-01

    Knowing the expected temporal evolution of the proportion of different cell types in sample tissues gives an indication about the progression of the disease and its possible response to drugs. Such systems have been modelled using Markov processes. We here consider an experimentally realistic scenario in which transition probabilities are estimated from noisy cell population size measurements. Using aggregated data of FACS measurements, we develop MMSE and ML estimators and formulate two problems to find the minimum number of required samples and measurements to guarantee the accuracy of predicted population sizes. Our numerical results show that the convergence mechanism of transition probabilities and steady states differ widely from the real values if one uses the standard deterministic approach for noisy measurements. This provides support for our argument that for the analysis of FACS data one should consider the observed state as a random variable. The second problem we address is about the consequences of estimating the probability of a cell being in a particular state from measurements of small population of cells. We show how the uncertainty arising from small sample sizes can be captured by a distribution for the state probability.

  5. Gray bootstrap method for estimating frequency-varying random vibration signals with small samples

    Directory of Open Access Journals (Sweden)

    Wang Yanqing

    2014-04-01

    Full Text Available During environment testing, the estimation of random vibration signals (RVS is an important technique for the airborne platform safety and reliability. However, the available methods including extreme value envelope method (EVEM, statistical tolerances method (STM and improved statistical tolerance method (ISTM require large samples and typical probability distribution. Moreover, the frequency-varying characteristic of RVS is usually not taken into account. Gray bootstrap method (GBM is proposed to solve the problem of estimating frequency-varying RVS with small samples. Firstly, the estimated indexes are obtained including the estimated interval, the estimated uncertainty, the estimated value, the estimated error and estimated reliability. In addition, GBM is applied to estimating the single flight testing of certain aircraft. At last, in order to evaluate the estimated performance, GBM is compared with bootstrap method (BM and gray method (GM in testing analysis. The result shows that GBM has superiority for estimating dynamic signals with small samples and estimated reliability is proved to be 100% at the given confidence level.

  6. A systematic random sampling scheme optimized to detect the proportion of rare synapses in the neuropil.

    Science.gov (United States)

    da Costa, Nuno Maçarico; Hepp, Klaus; Martin, Kevan A C

    2009-05-30

    Synapses can only be morphologically identified by electron microscopy and this is often a very labor-intensive and time-consuming task. When quantitative estimates are required for pathways that contribute a small proportion of synapses to the neuropil, the problems of accurate sampling are particularly severe and the total time required may become prohibitive. Here we present a sampling method devised to count the percentage of rarely occurring synapses in the neuropil using a large sample (approximately 1000 sampling sites), with the strong constraint of doing it in reasonable time. The strategy, which uses the unbiased physical disector technique, resembles that used in particle physics to detect rare events. We validated our method in the primary visual cortex of the cat, where we used biotinylated dextran amine to label thalamic afferents and measured the density of their synapses using the physical disector method. Our results show that we could obtain accurate counts of the labeled synapses, even when they represented only 0.2% of all the synapses in the neuropil.

  7. Chronic Stereotype Threat Is Associated With Mathematical Achievement on Representative Sample of Secondary Schoolgirls: The Role of Gender Identification, Working Memory, and Intellectual Helplessness

    OpenAIRE

    Sylwia Bedyńska; Izabela Krejtz; Grzegorz Sedek

    2018-01-01

    Stereotype threat affects performance in many different groups across many different domains. Despite a large body of experimental research on situational stereotype threat, little attention has been paid to the consequences of repeated experience of stereotype threat. Using structural equation modeling on data from a representative sample of girls from secondary schools, the current research examined the relations of chronic stereotype threat with mathematical achievement, and effectiveness ...

  8. Informed decision-making with and for people with dementia - efficacy of the PRODECIDE education program for legal representatives: protocol of a randomized controlled trial (PRODECIDE-RCT).

    Science.gov (United States)

    Lühnen, Julia; Haastert, Burkhard; Mühlhauser, Ingrid; Richter, Tanja

    2017-09-15

    In Germany, the guardianship system provides adults who are no longer able to handle their own affairs a court-appointed legal representative, for support without restriction of legal capacity. Although these representatives only rarely are qualified in healthcare, they nevertheless play decisive roles in the decision-making processes for people with dementia. Previously, we developed an education program (PRODECIDE) to address this shortcoming and tested it for feasibility. Typical, autonomy-restricting decisions in the care of people with dementia-namely, using percutaneous endoscopic gastrostomy (PEG) or physical restrains (PR), or the prescription of antipsychotic drugs (AP)-were the subject areas trained. The training course aims to enhance the competency of legal representatives in informed decision-making. In this study, we will evaluate the efficacy of the PRODECIDE education program. A randomized controlled trial with a six-month follow-up will be conducted to compare the PRODECIDE education program with standard care, enrolling legal representatives (N = 216). The education program lasts 10 h and comprises four modules: A, decision-making processes and methods; and B, C and D, evidence-based knowledge about PEG, PR and AP, respectively. The primary outcome measure is knowledge, which is operationalized as the understanding of decision-making processes in healthcare affairs and in setting realistic expectations about benefits and harms of PEG, PR and AP in people with dementia. Secondary outcomes are sufficient and sustainable knowledge and percentage of persons concerned affected by PEG, FEM or AP. A qualitative process evaluation will be performed. Additionally, to support implementation, a concept for translating the educational contents into e-learning modules will be developed. The study results will show whether the efficacy of the education program could justify its implementation into the regular training curricula for legal representatives

  9. Iterative random vs. Kennard-Stone sampling for IR spectrum-based classification task using PLS2-DA

    Science.gov (United States)

    Lee, Loong Chuen; Liong, Choong-Yeun; Jemain, Abdul Aziz

    2018-04-01

    External testing (ET) is preferred over auto-prediction (AP) or k-fold-cross-validation in estimating more realistic predictive ability of a statistical model. With IR spectra, Kennard-stone (KS) sampling algorithm is often used to split the data into training and test sets, i.e. respectively for model construction and for model testing. On the other hand, iterative random sampling (IRS) has not been the favored choice though it is theoretically more likely to produce reliable estimation. The aim of this preliminary work is to compare performances of KS and IRS in sampling a representative training set from an attenuated total reflectance - Fourier transform infrared spectral dataset (of four varieties of blue gel pen inks) for PLS2-DA modeling. The `best' performance achievable from the dataset is estimated with AP on the full dataset (APF, error). Both IRS (n = 200) and KS were used to split the dataset in the ratio of 7:3. The classic decision rule (i.e. maximum value-based) is employed for new sample prediction via partial least squares - discriminant analysis (PLS2-DA). Error rate of each model was estimated repeatedly via: (a) AP on full data (APF, error); (b) AP on training set (APS, error); and (c) ET on the respective test set (ETS, error). A good PLS2-DA model is expected to produce APS, error and EVS, error that is similar to the APF, error. Bearing that in mind, the similarities between (a) APS, error vs. APF, error; (b) ETS, error vs. APF, error and; (c) APS, error vs. ETS, error were evaluated using correlation tests (i.e. Pearson and Spearman's rank test), using series of PLS2-DA models computed from KS-set and IRS-set, respectively. Overall, models constructed from IRS-set exhibits more similarities between the internal and external error rates than the respective KS-set, i.e. less risk of overfitting. In conclusion, IRS is more reliable than KS in sampling representative training set.

  10. Randomized controlled trial of attention bias modification in a racially diverse, socially anxious, alcohol dependent sample.

    Science.gov (United States)

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

    2016-12-01

    Attention biases may be an important treatment target for both alcohol dependence and social anxiety. This is the first ABM trial to investigate two (vs. one) targets of attention bias within a sample with co-occurring symptoms of social anxiety and alcohol dependence. Additionally, we used trial-level bias scores (TL-BS) to capture the phenomena of attention bias in a more ecologically valid, dynamic way compared to traditional attention bias scores. Adult participants (N = 86; 41% Female; 52% African American; 40% White) with elevated social anxiety symptoms and alcohol dependence were randomly assigned to an 8-session training condition in this 2 (Social Anxiety ABM vs. Social Anxiety Control) by 2 (Alcohol ABM vs. Alcohol Control) design. Symptoms of social anxiety, alcohol dependence, and attention bias were assessed across time. Multilevel models estimated the trajectories for each measure within individuals, and tested whether these trajectories differed according to the randomized training conditions. Across time, there were significant or trending decreases in all attention TL-BS parameters (but not traditional attention bias scores) and most symptom measures. However, there were not significant differences in the trajectories of change between any ABM and control conditions for any symptom measures. These findings add to previous evidence questioning the robustness of ABM and point to the need to extend the effects of ABM to samples that are racially diverse and/or have co-occurring psychopathology. The results also illustrate the potential importance of calculating trial-level attention bias scores rather than only including traditional bias scores. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Convergence analysis for Latin-hypercube lattice-sample selection strategies for 3D correlated random hydraulic-conductivity fields

    OpenAIRE

    Simuta-Champo, R.; Herrera-Zamarrón, G. S.

    2010-01-01

    The Monte Carlo technique provides a natural method for evaluating uncertainties. The uncertainty is represented by a probability distribution or by related quantities such as statistical moments. When the groundwater flow and transport governing equations are solved and the hydraulic conductivity field is treated as a random spatial function, the hydraulic head, velocities and concentrations also become random spatial functions. When that is the case, for the stochastic simulation of groundw...

  13. Relative efficiency and sample size for cluster randomized trials with variable cluster sizes.

    Science.gov (United States)

    You, Zhiying; Williams, O Dale; Aban, Inmaculada; Kabagambe, Edmond Kato; Tiwari, Hemant K; Cutter, Gary

    2011-02-01

    The statistical power of cluster randomized trials depends on two sample size components, the number of clusters per group and the numbers of individuals within clusters (cluster size). Variable cluster sizes are common and this variation alone may have significant impact on study power. Previous approaches have taken this into account by either adjusting total sample size using a designated design effect or adjusting the number of clusters according to an assessment of the relative efficiency of unequal versus equal cluster sizes. This article defines a relative efficiency of unequal versus equal cluster sizes using noncentrality parameters, investigates properties of this measure, and proposes an approach for adjusting the required sample size accordingly. We focus on comparing two groups with normally distributed outcomes using t-test, and use the noncentrality parameter to define the relative efficiency of unequal versus equal cluster sizes and show that statistical power depends only on this parameter for a given number of clusters. We calculate the sample size required for an unequal cluster sizes trial to have the same power as one with equal cluster sizes. Relative efficiency based on the noncentrality parameter is straightforward to calculate and easy to interpret. It connects the required mean cluster size directly to the required sample size with equal cluster sizes. Consequently, our approach first determines the sample size requirements with equal cluster sizes for a pre-specified study power and then calculates the required mean cluster size while keeping the number of clusters unchanged. Our approach allows adjustment in mean cluster size alone or simultaneous adjustment in mean cluster size and number of clusters, and is a flexible alternative to and a useful complement to existing methods. Comparison indicated that we have defined a relative efficiency that is greater than the relative efficiency in the literature under some conditions. Our measure

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

    Science.gov (United States)

    Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    1997-01-01

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

  16. The contribution of simple random sampling to observed variations in faecal egg counts.

    Science.gov (United States)

    Torgerson, Paul R; Paul, Michaela; Lewis, Fraser I

    2012-09-10

    It has been over 100 years since the classical paper published by Gosset in 1907, under the pseudonym "Student", demonstrated that yeast cells suspended in a fluid and measured by a haemocytometer conformed to a Poisson process. Similarly parasite eggs in a faecal suspension also conform to a Poisson process. Despite this there are common misconceptions how to analyse or interpret observations from the McMaster or similar quantitative parasitic diagnostic techniques, widely used for evaluating parasite eggs in faeces. The McMaster technique can easily be shown from a theoretical perspective to give variable results that inevitably arise from the random distribution of parasite eggs in a well mixed faecal sample. The Poisson processes that lead to this variability are described and illustrative examples of the potentially large confidence intervals that can arise from observed faecal eggs counts that are calculated from the observations on a McMaster slide. Attempts to modify the McMaster technique, or indeed other quantitative techniques, to ensure uniform egg counts are doomed to failure and belie ignorance of Poisson processes. A simple method to immediately identify excess variation/poor sampling from replicate counts is provided. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Active Learning Not Associated with Student Learning in a Random Sample of College Biology Courses

    Science.gov (United States)

    Andrews, T. M.; Leonard, M. J.; Colgrove, C. A.; Kalinowski, S. T.

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning. PMID:22135373

  18. Sampling of suspended particulate matter using particle traps in the Rhône River: Relevance and representativeness for the monitoring of contaminants.

    Science.gov (United States)

    Masson, M; Angot, H; Le Bescond, C; Launay, M; Dabrin, A; Miège, C; Le Coz, J; Coquery, M

    2018-05-10

    Monitoring hydrophobic contaminants in surface freshwaters requires measuring contaminant concentrations in the particulate fraction (sediment or suspended particulate matter, SPM) of the water column. Particle traps (PTs) have been recently developed to sample SPM as cost-efficient, easy to operate and time-integrative tools. But the representativeness of SPM collected with PTs is not fully understood, notably in terms of grain size distribution and particulate organic carbon (POC) content, which could both skew particulate contaminant concentrations. The aim of this study was to evaluate the representativeness of SPM characteristics (i.e. grain size distribution and POC content) and associated contaminants (i.e. polychlorinated biphenyls, PCBs; mercury, Hg) in samples collected in a large river using PTs for differing hydrological conditions. Samples collected using PTs (n = 74) were compared with samples collected during the same time period by continuous flow centrifugation (CFC). The grain size distribution of PT samples shifted with increasing water discharge: the proportion of very fine silts (2-6 μm) decreased while that of coarse silts (27-74 μm) increased. Regardless of water discharge, POC contents were different likely due to integration by PT of high POC-content phytoplankton blooms or low POC-content flood events. Differences in PCBs and Hg concentrations were usually within the range of analytical uncertainties and could not be related to grain size or POC content shifts. Occasional Hg-enriched inputs may have led to higher Hg concentrations in a few PT samples (n = 4) which highlights the time-integrative capacity of the PTs. The differences of annual Hg and PCB fluxes calculated either from PT samples or CFC samples were generally below 20%. Despite some inherent limitations (e.g. grain size distribution bias), our findings suggest that PT sampling is a valuable technique to assess reliable spatial and temporal trends of particulate

  19. An R package for spatial coverage sampling and random sampling from compact geographical strata by k-means

    NARCIS (Netherlands)

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

    2010-01-01

    Both for mapping and for estimating spatial means of an environmental variable, the accuracy of the result will usually be increased by dispersing the sample locations so that they cover the study area as uniformly as possible. We developed a new R package for designing spatial coverage samples for

  20. Determination of calcium, potassium, manganese, iron, copper and zinc levels in representative samples of two onion cultivars using total reflection X-ray fluorescence and ultrasound extraction procedure

    International Nuclear Information System (INIS)

    Alvarez, J.; Marco, L.M.; Arroyo, J.; Greaves, E.D.; Rivas, R.

    2003-01-01

    The chemical characterization of onion cultivar samples is an important tool for the enhancement of their productivity due to the fact that chemical composition is closed related to the quality of the products. A new sample preparation procedure for elemental characterization is proposed, involving the acid extraction of the analytes from crude samples by means of an ultrasonic bath, avoiding the required digestion of samples in vegetable tissue analysis. The technique of total reflection X-ray fluorescence (TXRF) was successfully applied for the simultaneous determination of the elements Ca, K, Mn, Fe, Cu and Zn. The procedure was compared with the wet ashing and dry ashing procedures for all the elements using multivariate analysis and the Scheffe test. The technique of flame atomic absorption spectrometry (FAAS) was employed for comparison purposes and accuracy evaluation of the proposed analysis method. A good agreement between the two techniques was found when using the dry ashing and ultrasound leaching procedures. The levels of each element found for representative samples of two onion cultivars (Yellow Granex PRR 502 and 438 Granex) were also compared by the same method. Levels of K, Mn and Zn were significantly higher in the 438 Granex cultivar, while levels of Ca, Fe and Cu were significantly higher in the Yellow Granex PRR 502 cultivar

  1. The development and validation of the Male Genital Self-Image Scale: results from a nationally representative probability sample of men in the United States.

    Science.gov (United States)

    Herbenick, Debby; Schick, Vanessa; Reece, Michael; Sanders, Stephanie A; Fortenberry, J Dennis

    2013-06-01

    Numerous factors may affect men's sexual experiences, including their health status, past trauma or abuse, medication use, relationships, mood, anxiety, and body image. Little research has assessed the influence of men's genital self-image on their sexual function or behaviors and none has done so in a nationally representative sample. The purpose of this study was to, in a nationally representative probability sample of men ages 18 to 60, assess the reliability and validity of the Male Genital Self-Image Scale (MGSIS), and to examine the relationship between scores on the MGSIS and men's scores on the International Index of Erectile Function (IIEF). The MGSIS was developed in two stages. Phase One involved a review of the literature and an analysis of cross-sectional survey data. Phase Two involved an administration of the scale items to a nationally representative sample of men in the United States ages 18 to 60. Measures include demographic items, the IIEF, and the MGSIS. Overall, most men felt positively about their genitals. However, 24.6% of men expressed some discomfort letting a healthcare provider examine their genitals and about 20% reported dissatisfaction with their genital size. The MGSIS was found to be reliable and valid, with the MGSIS-5 (consisting of five items) being the best fit to the data. The MGSIS was found to be a reliable and valid measure. In addition, men's scores on the MGSIS-5 were found to be positively related to men's scores on the IIEF. © 2013 International Society for Sexual Medicine.

  2. A random sampling approach for robust estimation of tissue-to-plasma ratio from extremely sparse data.

    Science.gov (United States)

    Chu, Hui-May; Ette, Ene I

    2005-09-02

    his study was performed to develop a new nonparametric approach for the estimation of robust tissue-to-plasma ratio from extremely sparsely sampled paired data (ie, one sample each from plasma and tissue per subject). Tissue-to-plasma ratio was estimated from paired/unpaired experimental data using independent time points approach, area under the curve (AUC) values calculated with the naïve data averaging approach, and AUC values calculated using sampling based approaches (eg, the pseudoprofile-based bootstrap [PpbB] approach and the random sampling approach [our proposed approach]). The random sampling approach involves the use of a 2-phase algorithm. The convergence of the sampling/resampling approaches was investigated, as well as the robustness of the estimates produced by different approaches. To evaluate the latter, new data sets were generated by introducing outlier(s) into the real data set. One to 2 concentration values were inflated by 10% to 40% from their original values to produce the outliers. Tissue-to-plasma ratios computed using the independent time points approach varied between 0 and 50 across time points. The ratio obtained from AUC values acquired using the naive data averaging approach was not associated with any measure of uncertainty or variability. Calculating the ratio without regard to pairing yielded poorer estimates. The random sampling and pseudoprofile-based bootstrap approaches yielded tissue-to-plasma ratios with uncertainty and variability. However, the random sampling approach, because of the 2-phase nature of its algorithm, yielded more robust estimates and required fewer replications. Therefore, a 2-phase random sampling approach is proposed for the robust estimation of tissue-to-plasma ratio from extremely sparsely sampled data.

  3. Prevalence of sleep duration on an average school night among 4 nationally representative successive samples of American high school students, 2007-2013.

    Science.gov (United States)

    Basch, Charles E; Basch, Corey H; Ruggles, Kelly V; Rajan, Sonali

    2014-12-11

    Consistency, quality, and duration of sleep are important determinants of health. We describe sleep patterns among demographically defined subgroups from the Youth Risk Behavior Surveillance System reported in 4 successive biennial representative samples of American high school students (2007 to 2013). Across the 4 waves of data collection, 6.2% to 7.7% of females and 8.0% to 9.4% of males reported obtaining 9 or more hours of sleep. Insufficient duration of sleep is pervasive among American high school students. Despite substantive public health implications, intervention research on this topic has received little attention.

  4. The study of combining Latin Hypercube Sampling method and LU decomposition method (LULHS method) for constructing spatial random field

    Science.gov (United States)

    WANG, P. T.

    2015-12-01

    Groundwater modeling requires to assign hydrogeological properties to every numerical grid. Due to the lack of detailed information and the inherent spatial heterogeneity, geological properties can be treated as random variables. Hydrogeological property is assumed to be a multivariate distribution with spatial correlations. By sampling random numbers from a given statistical distribution and assigning a value to each grid, a random field for modeling can be completed. Therefore, statistics sampling plays an important role in the efficiency of modeling procedure. Latin Hypercube Sampling (LHS) is a stratified random sampling procedure that provides an efficient way to sample variables from their multivariate distributions. This study combines the the stratified random procedure from LHS and the simulation by using LU decomposition to form LULHS. Both conditional and unconditional simulations of LULHS were develpoed. The simulation efficiency and spatial correlation of LULHS are compared to the other three different simulation methods. The results show that for the conditional simulation and unconditional simulation, LULHS method is more efficient in terms of computational effort. Less realizations are required to achieve the required statistical accuracy and spatial correlation.

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

    Science.gov (United States)

    NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

    2017-08-01

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

  6. [Considering housing arrangements in elderly life: factors influencing plans concerning future housing arrangements and preferences in a representative sample of 45+ year olds].

    Science.gov (United States)

    Spangenberg, L; Glaesmer, H; Brähler, E; Kersting, A; Strauß, B

    2013-04-01

    Providing care and support for the elderly is a future challenge. Using regression analysis, a representative population-based sample (n = 1,445) was examined with respect to whether they had considered future housing and which variables influenced their thoughts and preferences. The majority of the sample reported thinking about housing in old age and preferred to stay at home in old age. Thoughts about future housing and housing preferences were predicted by different factors in the age groups analyzed. Thinking about future housing was positively associated with increasing age and depression. Other relevant predictors were gender, living with a partner, images of old age (especially negative ones), and anticipated subjective health. These variables also predicted housing preferences. Thoughts about future living arrangements are widespread, and their importance increases with age. The wishes reported do contrast to a certain extent with reality. Planning future care as well as developing consultation guidelines should address these issues while considering the reported influences.

  7. Hardware architecture for projective model calculation and false match refining using random sample consensus algorithm

    Science.gov (United States)

    Azimi, Ehsan; Behrad, Alireza; Ghaznavi-Ghoushchi, Mohammad Bagher; Shanbehzadeh, Jamshid

    2016-11-01

    The projective model is an important mapping function for the calculation of global transformation between two images. However, its hardware implementation is challenging because of a large number of coefficients with different required precisions for fixed point representation. A VLSI hardware architecture is proposed for the calculation of a global projective model between input and reference images and refining false matches using random sample consensus (RANSAC) algorithm. To make the hardware implementation feasible, it is proved that the calculation of the projective model can be divided into four submodels comprising two translations, an affine model and a simpler projective mapping. This approach makes the hardware implementation feasible and considerably reduces the required number of bits for fixed point representation of model coefficients and intermediate variables. The proposed hardware architecture for the calculation of a global projective model using the RANSAC algorithm was implemented using Verilog hardware description language and the functionality of the design was validated through several experiments. The proposed architecture was synthesized by using an application-specific integrated circuit digital design flow utilizing 180-nm CMOS technology as well as a Virtex-6 field programmable gate array. Experimental results confirm the efficiency of the proposed hardware architecture in comparison with software implementation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Tao Song

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

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

    Science.gov (United States)

    Song, Tao; Gu, Hong

    2014-01-01

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

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

    Science.gov (United States)

    Schmidt, Jennifer; Martin, Alexandra

    2016-09-01

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

  12. Rigidity of the far-right? Motivated social cognition in a nationally representative sample of Hungarians on the eve of the far-right breakthrough in the 2010 elections.

    Science.gov (United States)

    Lönnqvist, Jan-Erik; Szabó, Zsolt Péter; Kelemen, Laszlo

    2018-04-26

    We investigated the "rigidity of the right" hypothesis in the context of the far-right breakthrough in the 2010 Hungarian parliamentary elections. This hypothesis suggests that psychological characteristics having to do with need for security and certainty attract people to a broad-based right-wing ideology. A nationally representative sample (N = 1000) in terms of age, gender and place of residence was collected by means of the random walking method and face-to-face interviews. Voters of JOBBIK (n = 124), the radically nationalist conservative far-right party, scored lower on System Justifying Belief, Belief in a Just World (Global) and higher on Need for Cognition than other voters. Our results contradict the "rigidity of the right" hypothesis: JOBBIK voters scored, on many measures, opposite to what the hypothesis would predict. © 2018 International Union of Psychological Science.

  13. Marital status as a candidate moderator variable of male-female differences in sexual jealousy: the need for representative population samples.

    Science.gov (United States)

    Voracek, M

    2001-04-01

    Evolutionary psychological theories predict pronounced and universal male-female differences in sexual jealousy. Recent cross-cultural research, using the forced-choice jealousy items pioneered by Buss, et al., 1992, repeatedly found a large sex differential on these self-report measures: men significantly more often than women choose their mate's imagined sexual infidelity to be more distressing or upsetting to them than an imagined emotional infidelity. However, this body of evidence is solely based on undergraduate samples and does not take into account demographic factors. This study examined male-female differences in sexual jealousy in a community sample (N = 335, Eastern Austria). Within a logistic regression model, with other variables controlled for, marital status was a stronger predictor for sexual jealousy than respondents' sex. Contrary to previous research, the sex differential's effect size was only modest. These findings stress the pitfalls of prematurely generalizing evidence from undergraduate samples to the general population and the need for representative population samples in this research area.

  14. Randomization-Based Inference about Latent Variables from Complex Samples: The Case of Two-Stage Sampling

    Science.gov (United States)

    Li, Tiandong

    2012-01-01

    In large-scale assessments, such as the National Assessment of Educational Progress (NAEP), plausible values based on Multiple Imputations (MI) have been used to estimate population characteristics for latent constructs under complex sample designs. Mislevy (1991) derived a closed-form analytic solution for a fixed-effect model in creating…

  15. At convenience and systematic random sampling: effects on the prognostic value of nuclear area assessments in breast cancer patients.

    Science.gov (United States)

    Jannink, I; Bennen, J N; Blaauw, J; van Diest, P J; Baak, J P

    1995-01-01

    This study compares the influence of two different nuclear sampling methods on the prognostic value of assessments of mean and standard deviation of nuclear area (MNA, SDNA) in 191 consecutive invasive breast cancer patients with long term follow up. The first sampling method used was 'at convenience' sampling (ACS); the second, systematic random sampling (SRS). Both sampling methods were tested with a sample size of 50 nuclei (ACS-50 and SRS-50). To determine whether, besides the sampling methods, sample size had impact on prognostic value as well, the SRS method was also tested using a sample size of 100 nuclei (SRS-100). SDNA values were systematically lower for ACS, obviously due to (unconsciously) not including small and large nuclei. Testing prognostic value of a series of cut off points, MNA and SDNA values assessed by the SRS method were prognostically significantly stronger than the values obtained by the ACS method. This was confirmed in Cox regression analysis. For the MNA, the Mantel-Cox p-values from SRS-50 and SRS-100 measurements were not significantly different. However, for the SDNA, SRS-100 yielded significantly lower p-values than SRS-50. In conclusion, compared with the 'at convenience' nuclear sampling method, systematic random sampling of nuclei is not only superior with respect to reproducibility of results, but also provides a better prognostic value in patients with invasive breast cancer.

  16. Body Mass Index Percentile Curves for 7 To 18 Year Old Children and Adolescents; are the Sample Populations from Tehran Nationally Representative?

    Directory of Open Access Journals (Sweden)

    Mostafa Hosseini

    2016-06-01

    Full Text Available Background: The children’s body composition status is an important indicator of health condition evaluated through their body mass index (BMI. We aimed to provide standardized percentile curves of BMI in a population of Iranian children and adolescents. We assessed the nationally representative of sample populations from Tehran. Materials and Methods: A total sample of 14,865 children aged 7-18 years was gathered. The Lambda-Mu-Sigma method was used to derive sex-specific smoothed centiles for age via the Lambda-Mu-Sigma Chart Maker Program. Finally, the prevalence of overweight and obesity with 95% confidence interval (CI was calculated. Results: BMI percentiles obtained from Tehran’s population, except for the 10th percentile, seem to be very slightly greater than the urban boys from all over Iran. BMI percentiles have an increasing trend by age that is S-shaped with a slight slope. Only in the 90th and 97th percentiles of BMI for girls, this rising trend seems to stop. Boys generally have higher BMIs than girls. The exceptions are younger ages of 90th and 97th percentiles and older ages of 3rd and 10th percentiles. A total number of 1,008 (13.20%; 95% CI: 12.46-13.98 boys and 603 (8.34%; 95% CI: 7.72-9.00 girls were categorized as overweight and obese. Obesity were observed in 402 (5.27%; 95% CI: 4.79-5.79 boys and 274 (3.76%; 95% CI: 3.35-4.22 girls. Conclusion: We construct BMI percentile curves by age and gender for 7 to 18 years Iranian children and adolescents. It can be concluded that sample populations from Tehran are nationally representative.

  17. Benefits of expressive writing in reducing test anxiety: A randomized controlled trial in Chinese samples.

    Science.gov (United States)

    Shen, Lujun; Yang, Lei; Zhang, Jing; Zhang, Meng

    2018-01-01

    To explore the effect of expressive writing of positive emotions on test anxiety among senior-high-school students. The Test Anxiety Scale (TAS) was used to assess the anxiety level of 200 senior-high-school students. Seventy-five students with high anxiety were recruited and divided randomly into experimental and control groups. Each day for 30 days, the experimental group engaged in 20 minutes of expressive writing of positive emotions, while the control group was asked to merely write down their daily events. A second test was given after the month-long experiment to analyze whether there had been a reduction in anxiety among the sample. Quantitative data was obtained from TAS scores. The NVivo10.0 software program was used to examine the frequency of particular word categories used in participants' writing manuscripts. Senior-high-school students indicated moderate to high test anxiety. There was a significant difference in post-test results (P 0.05). Students' writing manuscripts were mainly encoded on five code categories: cause, anxiety manifestation, positive emotion, insight and evaluation. There was a negative relation between positive emotion, insight codes and test anxiety. There were significant differences in the positive emotion, anxiety manifestation, and insight code categories between the first 10 days' manuscripts and the last 10 days' ones. Long-term expressive writing of positive emotions appears to help reduce test anxiety by using insight and positive emotion words for Chinese students. Efficient and effective intervention programs to ease test anxiety can be designed based on this study.

  18. Benefits of expressive writing in reducing test anxiety: A randomized controlled trial in Chinese samples.

    Directory of Open Access Journals (Sweden)

    Lujun Shen

    Full Text Available To explore the effect of expressive writing of positive emotions on test anxiety among senior-high-school students.The Test Anxiety Scale (TAS was used to assess the anxiety level of 200 senior-high-school students. Seventy-five students with high anxiety were recruited and divided randomly into experimental and control groups. Each day for 30 days, the experimental group engaged in 20 minutes of expressive writing of positive emotions, while the control group was asked to merely write down their daily events. A second test was given after the month-long experiment to analyze whether there had been a reduction in anxiety among the sample. Quantitative data was obtained from TAS scores. The NVivo10.0 software program was used to examine the frequency of particular word categories used in participants' writing manuscripts.Senior-high-school students indicated moderate to high test anxiety. There was a significant difference in post-test results (P 0.05. Students' writing manuscripts were mainly encoded on five code categories: cause, anxiety manifestation, positive emotion, insight and evaluation. There was a negative relation between positive emotion, insight codes and test anxiety. There were significant differences in the positive emotion, anxiety manifestation, and insight code categories between the first 10 days' manuscripts and the last 10 days' ones.Long-term expressive writing of positive emotions appears to help reduce test anxiety by using insight and positive emotion words for Chinese students. Efficient and effective intervention programs to ease test anxiety can be designed based on this study.

  19. Benefits of expressive writing in reducing test anxiety: A randomized controlled trial in Chinese samples

    Science.gov (United States)

    Zhang, Jing; Zhang, Meng

    2018-01-01

    Purpose To explore the effect of expressive writing of positive emotions on test anxiety among senior-high-school students. Methods The Test Anxiety Scale (TAS) was used to assess the anxiety level of 200 senior-high-school students. Seventy-five students with high anxiety were recruited and divided randomly into experimental and control groups. Each day for 30 days, the experimental group engaged in 20 minutes of expressive writing of positive emotions, while the control group was asked to merely write down their daily events. A second test was given after the month-long experiment to analyze whether there had been a reduction in anxiety among the sample. Quantitative data was obtained from TAS scores. The NVivo10.0 software program was used to examine the frequency of particular word categories used in participants’ writing manuscripts. Results Senior-high-school students indicated moderate to high test anxiety. There was a significant difference in post-test results (P 0.05). Students’ writing manuscripts were mainly encoded on five code categories: cause, anxiety manifestation, positive emotion, insight and evaluation. There was a negative relation between positive emotion, insight codes and test anxiety. There were significant differences in the positive emotion, anxiety manifestation, and insight code categories between the first 10 days’ manuscripts and the last 10 days’ ones. Conclusions Long-term expressive writing of positive emotions appears to help reduce test anxiety by using insight and positive emotion words for Chinese students. Efficient and effective intervention programs to ease test anxiety can be designed based on this study. PMID:29401473

  20. Global Stratigraphy of Venus: Analysis of a Random Sample of Thirty-Six Test Areas

    Science.gov (United States)

    Basilevsky, Alexander T.; Head, James W., III

    1995-01-01

    The age relations between 36 impact craters with dark paraboloids and other geologic units and structures at these localities have been studied through photogeologic analysis of Magellan SAR images of the surface of Venus. Geologic settings in all 36 sites, about 1000 x 1000 km each, could be characterized using only 10 different terrain units and six types of structures. These units and structures form a major stratigraphic and geologic sequence (from oldest to youngest): (1) tessera terrain; (2) densely fractured terrains associated with coronae and in the form of remnants among plains; (3) fractured and ridged plains and ridge belts; (4) plains with wrinkle ridges; (5) ridges associated with coronae annulae and ridges of arachnoid annulae which are contemporary with wrinkle ridges of the ridged plains; (6) smooth and lobate plains; (7) fractures of coronae annulae, and fractures not related to coronae annulae, which disrupt ridged and smooth plains; (8) rift-associated fractures; and (9) craters with associated dark paraboloids, which represent the youngest 1O% of the Venus impact crater population (Campbell et al.), and are on top of all volcanic and tectonic units except the youngest episodes of rift-associated fracturing and volcanism; surficial streaks and patches are approximately contemporary with dark-paraboloid craters. Mapping of such units and structures in 36 randomly distributed large regions (each approximately 10(exp 6) sq km) shows evidence for a distinctive regional and global stratigraphic and geologic sequence. On the basis of this sequence we have developed a model that illustrates several major themes in the history of Venus. Most of the history of Venus (that of its first 80% or so) is not preserved in the surface geomorphological record. The major deformation associated with tessera formation in the period sometime between 0.5-1.0 b.y. ago (Ivanov and Basilevsky) is the earliest event detected. In the terminal stages of tessera fon

  1. Computer code ENDSAM for random sampling and validation of the resonance parameters covariance matrices of some major nuclear data libraries

    International Nuclear Information System (INIS)

    Plevnik, Lucijan; Žerovnik, Gašper

    2016-01-01

    Highlights: • Methods for random sampling of correlated parameters. • Link to open-source code for sampling of resonance parameters in ENDF-6 format. • Validation of the code on realistic and artificial data. • Validation of covariances in three major contemporary nuclear data libraries. - Abstract: Methods for random sampling of correlated parameters are presented. The methods are implemented for sampling of resonance parameters in ENDF-6 format and a link to the open-source code ENDSAM is given. The code has been validated on realistic data. Additionally, consistency of covariances of resonance parameters of three major contemporary nuclear data libraries (JEFF-3.2, ENDF/B-VII.1 and JENDL-4.0u2) has been checked.

  2. The pattern of physical comorbidity and the psychosocial determinants of depression: a prospective cohort study on a representative sample of family practice attendees in Slovenia.

    Science.gov (United States)

    Selič, Polona; Svab, Igor; Rifel, Janez; Pavlič, Danica Rotar; Cerne, Anja; King, Michael; Nazareth, Irwin

    2011-09-01

    Objectives This study aims to present the patterns of physical comorbidity in depressed patients and factors strongly associated with depression in a representative sample of Slovenian family practice attendees.Methods Medical data was obtained for 911 general practice attendees. Of them, 221 (24.3%) were diagnosed as depressed. The depressive states of the subjects were evaluated using the Composite International Diagnostic Interview (CIDI). Physical comorbidity was assessed with a questionnaire covering the most common health problems in the Slovenian adult population. Several psycho-social factors were also analysed.Results Those variables significantly related to ICD depression were included in multivariate binary logistic regression analysis, adjusted by age, gender and education. The calculation included the chi-square, odds ratio (OR) with confidence interval (95% CI) and P-value. A P-value financial situation were strongly associated with depression. The impact of concurrent incontinence and chronic bowel disease was also important, though somewhat weaker.

  3. Attention deficit hyperactivity disorder, other mental health problems, substance use, and driving: examination of a population-based, representative canadian sample.

    Science.gov (United States)

    Vingilis, Evelyn; Mann, Robert E; Erickson, Patricia; Toplak, Maggie; Kolla, Nathan J; Seeley, Jane; Jain, Umesh

    2014-01-01

    The purpose of this study is to examine the relationships among self-reported screening measures of attention deficit hyperactivity disorder (ADHD), other psychiatric problems, and driving-related outcomes in a provincially representative sample of adults 18 years and older living in the province of Ontario, Canada. The study examined the results of the Centre for Addictions and Mental Health (CAMH) Ontario Monitor, an ongoing repeated cross-sectional telephone survey of Ontario adults over a 2-year period. Measures included ADHD measures (Adult ADHD Self-Report Scale-V1.1 [ASRS-V1.1], previous ADHD diagnosis, ADHD medication use); psychiatric distress measures (General Health Questionnaire [GHQ12], use of pain, anxiety, and depression medication); antisocial behavior measure (The Antisocial Personality Disorder Scale from the Mini-International Neuropsychiatric Interview [APD]); substance use and abuse measures (alcohol, cannabis, and cocaine), Alcohol Use Disorders Identification Test (AUDIT), Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), driving-related outcomes (driving after drinking, driving after cannabis use, street racing, collisions in past year), and sociodemographics (gender, age, vehicle-kilometers traveled). A total of 4,014 Ontario residents were sampled, of which 3,485 reported having a valid driver's license. Overall, 3.22% screened positive for ADHD symptoms on the ASRS-V1.1 screening tool. A greater percentage of those who screened positive were younger, reported previous ADHD diagnosis and medication use, distress, antisocial behavior, anti-anxiety and antidepressant medication use, substance use, and social problems compared to those who screened negative. However, there were no statistically significant differences between those who screened positive or negative for ADHD symptoms on self-reported driving after having 2 or more drinks in the previous hour; within an hour of using cannabis, marijuana, or hash; or in a

  4. Randomized Comparison of Two Vaginal Self-Sampling Methods for Human Papillomavirus Detection: Dry Swab versus FTA Cartridge

    OpenAIRE

    Catarino, Rosa; Vassilakos, Pierre; Bilancioni, Aline; Vanden Eynde, Mathieu; Meyer-Hamme, Ulrike; Menoud, Pierre-Alain; Guerry, Fr?d?ric; Petignat, Patrick

    2015-01-01

    Background Human papillomavirus (HPV) self-sampling (self-HPV) is valuable in cervical cancer screening. HPV testing is usually performed on physician-collected cervical smears stored in liquid-based medium. Dry filters and swabs are an alternative. We evaluated the adequacy of self-HPV using two dry storage and transport devices, the FTA cartridge and swab. Methods A total of 130 women performed two consecutive self-HPV samples. Randomization determined which of the two tests was performed f...

  5. Suicide risk in a representative sample of people receiving HIV care: Time to target most-at-risk populations (ANRS VESPA2 French national survey).

    Science.gov (United States)

    Carrieri, Maria Patrizia; Marcellin, Fabienne; Fressard, Lisa; Préau, Marie; Sagaon-Teyssier, Luis; Suzan-Monti, Marie; Guagliardo, Valérie; Mora, Marion; Roux, Perrine; Dray-Spira, Rosemary; Spire, Bruno

    2017-01-01

    Suicide risk is high among people living with HIV (PLHIV). This study aimed to identify major correlates of suicide risk in a representative sample of PLHIV in France, in order to help target individuals who would benefit from suicide risk screening and psychiatric care. The ANRS VESPA2 cross-sectional survey (April 2011-January 2012) collected socio-demographic, medical and behavioral data from 3,022 PLHIV recruited in 73 French HIV hospital departments. The study sample comprised the 2,973 participants with available self-reported data on suicide risk (defined as having either thought about and planned to commit suicide during the previous 12 months or attempted suicide during the same period of time) and medical data on comorbidities. Weighted Poisson models adjusted for HCV co-infection and significant clinical variables were used to estimate the relationship between suicide risk and HIV transmission groups, experience with HIV disease and other psychosocial factors. Suicide risk was reported by 6.3% of PLHIV in the study sample. After adjustment for HIV immunological status and HCV co-infection, women (IRR [95%CI]:1.93 [1.17; 3.19]) and men who have sex with men (MSM) (1.97 [1.22; 3.19]) had a higher suicide risk than the rest of the sample. Moreover, the number of discrimination-related social contexts reported (1.39 [1.19; 1.61]), homelessness (4.87 [1.82; 13.02]), and reporting a feeling of loneliness (4.62 [3.06; 6.97]) were major predictors of suicide risk. Reducing the burden of precarious social conditions and discrimination is an important lever for preventing suicide risk among PLHIV in France. Comprehensive care models involving peer/community social interventions targeted at women and MSM need to be implemented to lower the risk of suicide in these specific subgroups of PLHIV.

  6. Suicide risk in a representative sample of people receiving HIV care: Time to target most-at-risk populations (ANRS VESPA2 French national survey.

    Directory of Open Access Journals (Sweden)

    Maria Patrizia Carrieri

    Full Text Available Suicide risk is high among people living with HIV (PLHIV. This study aimed to identify major correlates of suicide risk in a representative sample of PLHIV in France, in order to help target individuals who would benefit from suicide risk screening and psychiatric care.The ANRS VESPA2 cross-sectional survey (April 2011-January 2012 collected socio-demographic, medical and behavioral data from 3,022 PLHIV recruited in 73 French HIV hospital departments. The study sample comprised the 2,973 participants with available self-reported data on suicide risk (defined as having either thought about and planned to commit suicide during the previous 12 months or attempted suicide during the same period of time and medical data on comorbidities. Weighted Poisson models adjusted for HCV co-infection and significant clinical variables were used to estimate the relationship between suicide risk and HIV transmission groups, experience with HIV disease and other psychosocial factors.Suicide risk was reported by 6.3% of PLHIV in the study sample. After adjustment for HIV immunological status and HCV co-infection, women (IRR [95%CI]:1.93 [1.17; 3.19] and men who have sex with men (MSM (1.97 [1.22; 3.19] had a higher suicide risk than the rest of the sample. Moreover, the number of discrimination-related social contexts reported (1.39 [1.19; 1.61], homelessness (4.87 [1.82; 13.02], and reporting a feeling of loneliness (4.62 [3.06; 6.97] were major predictors of suicide risk.Reducing the burden of precarious social conditions and discrimination is an important lever for preventing suicide risk among PLHIV in France. Comprehensive care models involving peer/community social interventions targeted at women and MSM need to be implemented to lower the risk of suicide in these specific subgroups of PLHIV.

  7. A workforce survey of Australian osteopathy: analysis of a nationally-representative sample of osteopaths from the Osteopathy Research and Innovation Network (ORION) project.

    Science.gov (United States)

    Adams, Jon; Sibbritt, David; Steel, Amie; Peng, Wenbo

    2018-05-10

    Limited information is available regarding the profile and clinical practice characteristics of the osteopathy workforce in Australia. This paper reports such information by analysing data from a nationally-representative sample of Australian osteopaths. Data was obtained from a workforce survey of Australian osteopathy, investigating the characteristics of the practitioner, their practice, clinical management features and perceptions regarding research. The survey questionnaire was distributed to all registered osteopaths across Australia in 2016 as part of the Osteopathy Research and Innovation Network (ORION) project. A total of 992 Australian osteopaths participated in this study representing a response rate of 49.1%. The average age of the participants was 38.0 years with 58.1% being female and the majority holding a Bachelor or higher degree qualification related to the osteopathy professional. Approximately 80.0% of the osteopaths were practicing in an urban area, with most osteopaths working in multi-practitioner locations, having referral relationships with a range of health care practitioners, managing patients a number of musculoskeletal disorders, and providing multi-model treatment options. A total of 3.9 million patients were estimated to consult with osteopaths every year and an average of approximate 3.0 million hours were spent delivering osteopathy services per year. Further research is required to provide rich, in-depth examination regarding a range of osteopathy workforce issues which will help ensure safe, effective patient care to all receiving and providing treatments as part of the broader Australian health system.

  8. Association between the prevalence of depression and age in a large representative German sample of people aged 53 to 80 years.

    Science.gov (United States)

    Wild, Beate; Herzog, Wolfgang; Schellberg, Dieter; Lechner, Sabine; Niehoff, Doro; Brenner, Hermann; Rothenbacher, Dietrich; Stegmaier, Christa; Raum, Elke

    2012-04-01

    The aim of the study was to determine the association between the prevalence of clinically significant depression and age in a large representative sample of elderly German people. In the second follow-up (2005-2007) of the ESTHER cohort study, the 15-item geriatric depression scale (GDS-15) as well as a sociodemographic and clinical questionnaire were administered to a representative sample of 8270 people of ages 53 to 80 years. The prevalence of clinically significant depression was estimated using a GDS cut-off score of 5/6. Prevalence rates were estimated for the different age categories. Association between depression and age was analyzed using logistic regression, adjusted for gender, co-morbid medical disorders, education, marital status, physical activity, smoking, self-perceived cognitive impairment, and anti-depressive medication. Of the participants, 7878 (95.3%) completed more than twelve GDS items and were included in the study. The prevalence of clinically significant depression was 16.0% (95%CI = [15.2; 16.6]). The function of depression prevalence dependent on age group showed a U-shaped pattern (53-59: 21.0%, CI = [18.9; 23.3]; 60-64: 17.7%, CI = [15.7; 19.7]; 65-69: 12.6%, CI = [11.2; 14.0]; 70-74: 14.4%, CI = [12.6; 16.0]; 75-80: 17.1%, CI = [14.9; 19.4]). Adjusted odds ratios showed that the chances of being depressive decrease with the age category but remain relatively stable for people aged 65 and over. The prevalence of depression in the elderly seems to be associated with the age category. Adjusted odds ratios showed that people aged 60 and older had lower chances of being depressive than people aged 53 to 59 years. Copyright © 2011 John Wiley & Sons, Ltd.

  9. Dietary Acid Load and Potassium Intake Associate with Blood Pressure and Hypertension Prevalence in a Representative Sample of the German Adult Population

    Directory of Open Access Journals (Sweden)

    Danika Krupp

    2018-01-01

    Full Text Available Diets rich in fruits and vegetables, like the Dietary Approaches to Stop Hypertension (DASH-diet, are usually characterized by high potassium intake and reduced dietary acid load, and have been shown to reduce blood pressure (BP. However, the relevance of potential renal acid load (PRAL for BP has not been compared with the relevance to BP of urinary biomarker (K-urine- and dietary food frequency questionnaire (K-FFQ-based estimates of potassium intake in a general adult population sample. For 6788 participants (aged 18–79 years of the representative German Health-Interview and Examination Survey for Adults (DEGS1, associations of PRAL, K-urine, and K-FFQ with BP and hypertension prevalence were cross-sectionally examined in multivariable linear and logistic regression models. PRAL was significantly associated with higher systolic BP (p = 0.0002 and higher hypertension prevalence (Odds ratio [OR] high vs. low PRAL = 1.45, p = 0.0004 in models adjusted for age, sex, body mass index (BMI, estimated sodium intake, kidney function, relevant medication, and further important covariates. Higher estimates of K-FFQ and K-urine were related to lower systolic BP (p = 0.04 and p < 0.0001 and lower hypertension prevalence (OR = 0.82, p = 0.04 and OR = 0.77, p = 0.02 as well as a lower diastolic BP (p = 0.03 and p = 0.0003. Our results show, for the first time in a comparative analysis of a large representative population sample, significant relationships of BP and hypertension prevalence with questionnaire- and biomarker-based estimates of potassium intake and with an estimate of dietary acid load.

  10. Application of a stratified random sampling technique to the estimation and minimization of respirable quartz exposure to underground miners

    International Nuclear Information System (INIS)

    Makepeace, C.E.; Horvath, F.J.; Stocker, H.

    1981-11-01

    The aim of a stratified random sampling plan is to provide the best estimate (in the absence of full-shift personal gravimetric sampling) of personal exposure to respirable quartz among underground miners. One also gains information of the exposure distribution of all the miners at the same time. Three variables (or strata) are considered in the present scheme: locations, occupations and times of sampling. Random sampling within each stratum ensures that each location, occupation and time of sampling has equal opportunity of being selected without bias. Following implementation of the plan and analysis of collected data, one can determine the individual exposures and the mean. This information can then be used to identify those groups whose exposure contributes significantly to the collective exposure. In turn, this identification, along with other considerations, allows the mine operator to carry out a cost-benefit optimization and eventual implementation of engineering controls for these groups. This optimization and engineering control procedure, together with the random sampling plan, can then be used in an iterative manner to minimize the mean value of the distribution and collective exposures

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

    Directory of Open Access Journals (Sweden)

    Fady S. Moiety

    2014-06-01

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

  12. Prescription pain reliever misuse and levels of pain impairment: 3-year course in a nationally representative outpatient sample of US adults

    Directory of Open Access Journals (Sweden)

    Novak SP

    2016-06-01

    Full Text Available Scott P Novak,1 Cristie Glasheen,1 Carl L Roland,2 1Behavioral Health Epidemiology, RTI International, 2Clinical Sciences and Outcomes Evidence, Pfizer Inc., Durham, NC, USA Background: The primary aim of this work was to present the prevalence data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC, a representative 3-year longitudinal survey (ages 18+ years that captured information on patterns of self-reported pain interference and prescription pain reliever misuse. A second aim was to assess the degree to which the risk of various types of opioid misuse (onset, desistance, and incidence of dependence was related to the longitudinal course of self-reported pain interference over the 3-year period. Methods: We used a two-wave, nationally representative sample of adults (aged 18+ years in which the baseline data were collected during 2001–2002 and a single follow-up was obtained ~3 years later (2004–2005 with 34,332 respondents with complete data on study variables for both waves. Results: Our findings indicated that ~10% reported high pain interference in the past month at each wave. There was tremendous stability in levels of pain, with ~5% reporting consistent levels of high impairment over the 3-year study, a proxy for chronic pain. Levels of pain were more strongly associated with prescription pain reliever misuse concurrently rather than prospectively, and the association was largely linear, with the likelihood of misuse increasing with levels of pain. Finally, health service factors were also prominent predictors of onset, but not the outcomes, of desistance or transitions to problem use. Conclusion: This study is the first to use a nationally representative sample with measures of pain and drug use history collected over an extended period. These results may help provide clinicians with an understanding that the risk of misuse is greatest when pain is active and may help guide the selection of

  13. Impacts on quality of life related to dental caries in a national representative sample of Thai 12- and 15-year-olds.

    Science.gov (United States)

    Krisdapong, S; Prasertsom, P; Rattanarangsima, K; Sheiham, A

    2013-01-01

    Dental caries is generally given the highest priority in national oral health services for school-aged populations. Yet, there is no study exploring the impacts on quality of life specifically related to dental caries in national samples of school-aged children. This study assessed prevalence and characteristics of oral impacts attributed to dental caries on quality of life and compared them with overall oral health impacts. In addition, associations of oral impacts attributed to dental caries and dental caries status were investigated. A national representative sample of 1,063 12- and 811 15-year-olds completed a sociodemographic and behavioural questionnaire, and were orally examined and interviewed about oral health-related quality of life using the Child-OIDP or OIDP indexes, respectively. Associations of condition-specific impacts (CS impacts) attributed to dental caries with components of DMF were investigated using χ(2) tests and multivariate logistic regressions. CS impacts attributed to dental caries were reported by nearly half the children and such impacts accounted for half of overall oral impacts from all oral conditions. The majority of impacts were of little intensity and affected only 1-2 daily performances, particularly performances on Eating, Emotional stability and Cleaning teeth. CS impacts were significantly positively associated with number of decayed teeth, and strongly associated with severe decay. Copyright © 2012 S. Karger AG, Basel.

  14. Characterizing the context of sedentary lifestyles in a representative sample of adults: a cross-sectional study from the physical activity measurement study project.

    Science.gov (United States)

    Kim, Youngwon; Welk, Gregory J

    2015-12-09

    Research has clearly demonstrated that excess time spent on sedentary behavior (SB) increases health risks in the population. However, the lack of information on the context of SB in the population prevents a detailed understanding of sedentary lifestyles. The purpose of this study was to characterize the context of SB in a representative sample of adults and to examine differences across various socio-demographic indicators. A diverse sample of 1442 adults (ages 20-71 year) completed an interviewer-administered 24-h activity recall to provide detailed information about the time, type and location of the previous day's activities. All reported activities were matched with MET scores from the Compendium of Physical Activity but only SB (i.e., METS Work: 27.5%, Community: 24.8%, Home/Indoor: 20.5%, Home/Outdoor: 15.8%, and Transportation: 11.3%). Patterns of SB allocations varied considerably across different socio-demographic indicators indicating the extreme variability in SB in the population. The findings provide unique insights about the context of SB at the population level, and can serve as a guide for developing intervention/policy studies to reduce sedentary time and minimize disparities in SB.

  15. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

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

  16. Relationship between accuracy and number of samples on statistical quantity and contour map of environmental gamma-ray dose rate. Example of random sampling

    International Nuclear Information System (INIS)

    Matsuda, Hideharu; Minato, Susumu

    2002-01-01

    The accuracy of statistical quantity like the mean value and contour map obtained by measurement of the environmental gamma-ray dose rate was evaluated by random sampling of 5 different model distribution maps made by the mean slope, -1.3, of power spectra calculated from the actually measured values. The values were derived from 58 natural gamma dose rate data reported worldwide ranging in the means of 10-100 Gy/h rates and 10 -3 -10 7 km 2 areas. The accuracy of the mean value was found around ±7% even for 60 or 80 samplings (the most frequent number) and the standard deviation had the accuracy less than 1/4-1/3 of the means. The correlation coefficient of the frequency distribution was found 0.860 or more for 200-400 samplings (the most frequent number) but of the contour map, 0.502-0.770. (K.H.)

  17. Psychometric Properties of the Problematic Internet Use Questionnaire Short-Form (PIUQ-SF-6) in a Nationally Representative Sample of Adolescents.

    Science.gov (United States)

    Demetrovics, Zsolt; Király, Orsolya; Koronczai, Beatrix; Griffiths, Mark D; Nagygyörgy, Katalin; Elekes, Zsuzsanna; Tamás, Domokos; Kun, Bernadette; Kökönyei, Gyöngyi; Urbán, Róbert

    2016-01-01

    Despite the large number of measurement tools developed to assess problematic Internet use, numerous studies use measures with only modest investigation into their psychometric properties. The goal of the present study was to validate the short (6-item) version of the Problematic Internet Use Questionnaire (PIUQ) on a nationally representative adolescent sample (n = 5,005; mean age 16.4 years, SD = 0.87) and to determine a statistically established cut-off value. Data were collected within the framework of the European School Survey Project on Alcohol and Other Drugs project. Results showed an acceptable fit of the original three-factor structure to the data. In addition, a MIMIC model was carried out to justify the need for three distinct factors. The sample was divided into users at-risk of problematic Internet use and those with no-risk using a latent profile analysis. Two latent classes were obtained with 14.4% of adolescents belonging to the at-risk group. Concurrent and convergent validity were tested by comparing the two groups across a number of variables (i.e., time spent online, academic achievement, self-esteem, depressive symptoms, and preferred online activities). Using the at-risk latent profile analysis class as the gold standard, a cut-off value of 15 (out of 30) was suggested based on sensitivity and specificity analyses. In conclusion, the brief version of the (6-item) PIUQ also appears to be an appropriate measure to differentiate between Internet users at risk of developing problematic Internet use and those not at risk. Furthermore, due to its brevity, the shortened PIUQ is advantageous to utilize within large-scale surveys assessing many different behaviors and/or constructs by reducing the overall number of survey questions, and as a consequence, likely increasing completion rates.

  18. When addiction symptoms and life problems diverge: a latent class analysis of problematic gaming in a representative multinational sample of European adolescents.

    Science.gov (United States)

    Colder Carras, Michelle; Kardefelt-Winther, Daniel

    2018-04-01

    The proposed diagnosis of Internet gaming disorder (IGD) in DSM-5 has been criticized for "borrowing" criteria related to substance addiction, as this might result in misclassifying highly involved gamers as having a disorder. In this paper, we took a person-centered statistical approach to group adolescent gamers by levels of addiction-related symptoms and gaming-related problems, compared these groups to traditional scale scores for IGD, and checked how groups were related to psychosocial well-being using a preregistered analysis plan. We performed latent class analysis and regression with items from IGD and psychosocial well-being scales in a representative sample of 7865 adolescent European gamers. Symptoms and problems matched in only two groups: an IGD class (2.2%) having a high level of symptoms and problems and a Normative class (63.5%) having low levels of symptoms and problems. We also identified two classes comprising 30.9% of our sample that would be misclassified based on their report of gaming-related problems: an Engaged class (7.3%) that seemed to correspond to the engaged gamers described in previous literature, and a Concerned class (23.6%) reporting few symptoms but moderate to high levels of problems. Our findings suggest that a reformulation of IGD is needed. Treating Engaged gamers as having IGD when their poor well-being might not be gaming related may delay appropriate treatment, while Concerned gamers may need help to reduce gaming but would not be identified as such. Additional work to describe the phenomenology of these two groups would help refine diagnosis, prevention and treatment for IGD.

  19. Psychometric Properties of the Problematic Internet Use Questionnaire Short-Form (PIUQ-SF-6) in a Nationally Representative Sample of Adolescents

    Science.gov (United States)

    Demetrovics, Zsolt; Király, Orsolya; Koronczai, Beatrix; Griffiths, Mark D.; Nagygyörgy, Katalin; Elekes, Zsuzsanna; Tamás, Domokos; Kun, Bernadette; Kökönyei, Gyöngyi; Urbán, Róbert

    2016-01-01

    Despite the large number of measurement tools developed to assess problematic Internet use, numerous studies use measures with only modest investigation into their psychometric properties. The goal of the present study was to validate the short (6-item) version of the Problematic Internet Use Questionnaire (PIUQ) on a nationally representative adolescent sample (n = 5,005; mean age 16.4 years, SD = 0.87) and to determine a statistically established cut-off value. Data were collected within the framework of the European School Survey Project on Alcohol and Other Drugs project. Results showed an acceptable fit of the original three-factor structure to the data. In addition, a MIMIC model was carried out to justify the need for three distinct factors. The sample was divided into users at-risk of problematic Internet use and those with no-risk using a latent profile analysis. Two latent classes were obtained with 14.4% of adolescents belonging to the at-risk group. Concurrent and convergent validity were tested by comparing the two groups across a number of variables (i.e., time spent online, academic achievement, self-esteem, depressive symptoms, and preferred online activities). Using the at-risk latent profile analysis class as the gold standard, a cut-off value of 15 (out of 30) was suggested based on sensitivity and specificity analyses. In conclusion, the brief version of the (6-item) PIUQ also appears to be an appropriate measure to differentiate between Internet users at risk of developing problematic Internet use and those not at risk. Furthermore, due to its brevity, the shortened PIUQ is advantageous to utilize within large-scale surveys assessing many different behaviors and/or constructs by reducing the overall number of survey questions, and as a consequence, likely increasing completion rates. PMID:27504915

  20. Psychometric Properties of the Problematic Internet Use Questionnaire Short-Form (PIUQ-SF-6 in a Nationally Representative Sample of Adolescents.

    Directory of Open Access Journals (Sweden)

    Zsolt Demetrovics

    Full Text Available Despite the large number of measurement tools developed to assess problematic Internet use, numerous studies use measures with only modest investigation into their psychometric properties. The goal of the present study was to validate the short (6-item version of the Problematic Internet Use Questionnaire (PIUQ on a nationally representative adolescent sample (n = 5,005; mean age 16.4 years, SD = 0.87 and to determine a statistically established cut-off value. Data were collected within the framework of the European School Survey Project on Alcohol and Other Drugs project. Results showed an acceptable fit of the original three-factor structure to the data. In addition, a MIMIC model was carried out to justify the need for three distinct factors. The sample was divided into users at-risk of problematic Internet use and those with no-risk using a latent profile analysis. Two latent classes were obtained with 14.4% of adolescents belonging to the at-risk group. Concurrent and convergent validity were tested by comparing the two groups across a number of variables (i.e., time spent online, academic achievement, self-esteem, depressive symptoms, and preferred online activities. Using the at-risk latent profile analysis class as the gold standard, a cut-off value of 15 (out of 30 was suggested based on sensitivity and specificity analyses. In conclusion, the brief version of the (6-item PIUQ also appears to be an appropriate measure to differentiate between Internet users at risk of developing problematic Internet use and those not at risk. Furthermore, due to its brevity, the shortened PIUQ is advantageous to utilize within large-scale surveys assessing many different behaviors and/or constructs by reducing the overall number of survey questions, and as a consequence, likely increasing completion rates.

  1. High levels of adherence and viral suppression in a nationally representative sample of HIV-infected adults on antiretroviral therapy for 6, 12 and 18 months in Rwanda.

    Directory of Open Access Journals (Sweden)

    Batya Elul

    Full Text Available BACKGROUND: Generalizable data are needed on the magnitude and determinants of adherence and virological suppression among patients on antiretroviral therapy (ART in Africa. METHODS: We conducted a cross-sectional survey with chart abstraction, patient interviews and site assessments in a nationally representative sample of adults on ART for 6, 12 and 18 months at 20 sites in Rwanda. Adherence was assessed using 3- and 30-day patient recall. A systematically selected sub-sample had viral load (VL measurements. Multivariable logistic regression examined predictors of non-perfect (40 copies/ml. RESULTS: Overall, 1,417 adults were interviewed and 837 had VL measures. Ninety-four percent and 78% reported perfect adherence for the last 3 and 30 days, respectively. Eighty-three percent had undetectable VL. In adjusted models, characteristics independently associated with higher odds of non-perfect 30-day adherence were: being on ART for 18 months (vs. 6 months; younger age; reporting severe (vs. no or few side effects in the prior 30 days; having no documentation of CD4 cell count at ART initiation (vs. having a CD4 cell count of <200 cells/µL; alcohol use; and attending sites which initiated ART services in 2003-2004 and 2005 (vs. 2006-2007; sites with ≥600 (vs. <600 patients on ART; or sites with peer educators. Participation in an association for people living with HIV/AIDS; and receiving care at sites which regularly conduct home-visits were independently associated with lower odds of non-adherence. Higher odds of having a detectable VL were observed among patients at sites with peer educators. Being female; participating in an association for PLWHA; and using a reminder tool were independently associated with lower odds of having detectable VL. CONCLUSIONS: High levels of adherence and viral suppression were observed in the Rwandan national ART program, and associated with potentially modifiable factors.

  2. Perceived and Objective Measures of Neighborhood Walkability and Physical Activity among Adults in Japan: A Multilevel Analysis of a Nationally Representative Sample.

    Science.gov (United States)

    Hanibuchi, Tomoya; Nakaya, Tomoki; Yonejima, Mayuko; Honjo, Kaori

    2015-10-23

    Although associations between a person's neighborhood and their health have been studied internationally, most studies have been limited to a few cities or towns. Therefore, we used a nationally representative sample to explore whether perceived and objective neighborhood walkability was associated with the physical activity of residents. Data were analyzed from the Japanese General Social Surveys of 2010 (n = 2395; 1114 men and 1281 women). Perceived walkability was scored using factor analysis for the respondents' perceptions of neighborhood conditions, while objective walkability was measured using the geographic information system approach. Finally, multilevel logistic regression analysis was performed to examine whether neighborhood walkability was associated with the frequency of leisure-time physical activity (LTPA) among respondents. We found that perceived walkability was positively associated with the frequency of LTPA (odds ratio of the highest quartile was 1.53 (1.14-2.05) compared with the lowest quartile); however, objective walkability showed no association. When stratified by gender, an association between perceived walkability and LTPA was observed among women, but only a marginally significant association was present between objective walkability and LTPA among men. We conclude that the association between neighborhood walkability and LTPA can be partially generalized across Japan.

  3. Shadows of Beauty - Prevalence of Body Dysmorphic Concerns in Germany is Increasing: Data from Two Representative Samples from 2002 and 2013.

    Science.gov (United States)

    Gieler, Tanja; Schmutzer, Gabriele; Braehler, Elmar; Schut, Christina; Peters, Eva; Kupfer, Jörg

    2016-08-23

    Body dysmorphic disorder (BDD) is a psychosomatic disease associated with reduced quality of life and suicidal ideations. Increasing attention to beauty and the development of beauty industries lead to the hypothesis that BDD is increasing. The aim of this study was to test this hypothesis in two representative samples of Germans, assessed in 2002 and 2013. In 2002, n = 2,066 and in 2013, n = 2,508 Germans were asked to fill in the Dysmorphic Concern Questionnaire (DCQ), which assesses dysmorphic concerns. Subclinical and clinical dysmorphic concerns increased from 2002 to 2013 (subclinical from 0.5% to 2.6%, OR = 5.16 (CI95% = 2.64; 10.06); clinical from 0.5% to 1.0%, OR = 2.20 (CI95% = 1.03; 4.73). Women reported more dysmorphic concerns than men, with rates of 0.7% subclinical and 0.8 clinical BDD in women and 0.3% subclinical and 0.1% clinical BDD in men in 2002. In 2013, 2.8% subclinical and 1.2% clinical BDD were found in women and 2.4% subclinical and 0.8% clinical BDD in men. Further studies should assess predictors for developing a BDD and evaluate factors determining the efficacy of disease-specific psychotherapeutic and psychotropic drug treatments.

  4. Prospective Associations between Religiousness/Spirituality and Depression and Mediating Effects of Forgiveness in a Nationally Representative Sample of United States Adults.

    Science.gov (United States)

    Toussaint, Loren L; Marschall, Justin C; Williams, David R

    2012-01-01

    The present investigation examines the prospective associations of religiousness/spirituality with depression and the extent to which various dimensions of forgiveness act as mediating mechanisms of these associations. Data are from a nationally representative sample of United States adults who were first interviewed in 1998 and reinterviewed six months later. Measures of religiousness/spirituality, forgiveness, and various sociodemographics were collected. Depression was assessed using the Composite International Diagnostic Interview administered by trained interviewers. Results showed that religiousness/spirituality, forgiveness of oneself and others, and feeling forgiven by God were associated, both cross-sectionally and longitudinally, with depressive status. After controlling for initial depressive status, only forgiveness of oneself and others remained statistically significant predictors of depression. Path analyses revealed that religiousness/spirituality conveyed protective effects, prospectively, on depression by way of an indirect path through forgiveness of others but not forgiveness of oneself. Hence, forgiveness of others acts as a mechanism of the salutary effect of religiousness/spirituality, but forgiveness of oneself is an independent predictor. Conclusions regarding the continued development of this type of research and for the treatment of clients with depression are offered.

  5. Social Modulation or Hormonal Causation? Linkages of Testosterone with Sexual Activity and Relationship Quality in a Nationally Representative Longitudinal Sample of Older Adults.

    Science.gov (United States)

    Das, Aniruddha; Sawin, Nicole

    2016-11-01

    This study used population-representative longitudinal data from the 2005-2006 and 2010-2011 waves of the National Social Life, Health and Aging Project-a probability sample of US adults aged 57-85 at baseline (N = 650 women and 620 men)-to examine the causal direction in linkages of endogenous testosterone (T) with sexual activity and relationship quality. For both genders, our autoregressive effects indicated a large amount of temporal stability, not just in individual-level attributes (T, masturbation) but also dyadic ones (partnered sex, relationship quality)-indicating that a need for more nuanced theories of relational processes. Cross-lagged results suggested gender-specific effects-generally more consistent with sexual or relational modulation of T than with hormonal causation. Specifically, men's findings indicated their T might be elevated by their sexual (masturbatory) activity but not vice versa, although androgen levels did lower men's subsequent relationship quality. Women's T, in contrast, was negatively influenced not just by their higher relationship quality but also by their more frequent partnered sex-perhaps reflecting a changing function of sexual activity in late life.

  6. Addictive Potential of Internet Applications and Differential Correlates of Problematic Use in Internet Gamers versus Generalized Internet Users in a Representative Sample of Adolescents.

    Science.gov (United States)

    Rosenkranz, Tabea; Müller, Kai W; Dreier, Michael; Beutel, Manfred E; Wölfling, Klaus

    2017-01-01

    This paper examines the addictive potential of 8 different Internet applications, distinguishing male and female users. Moreover, differential correlates of problematic use are investigated in Internet gamers (IG) and generalized Internet users (GIU). In a representative sample of 5,667 adolescents aged 12-19 years, use of Internet applications, problematic Internet use, psychopathologic symptoms (emotional problems, hyperactivity/inattention, and psychosomatic complaints), personality (conscientiousness and extraversion), psychosocial correlates (perceived stress and self-efficacy), and coping strategies were assessed. The addictive potential of Internet applications was examined in boys and girls using regression analysis. MANOVAs were conducted to examine differential correlates of problematic Internet use between IG and GIU. Chatting and social networking most strongly predicted problematic Internet use in girls, while gaming was the strongest predictor in boys. Problematic IG exhibited multiple psychosocial problems compared to non-problematic IG. In problematic Internet users, GIU reported even higher psychosocial burden and displayed dysfunctional coping strategies more frequently than gamers. The results extend previous findings on the addictive potential of Internet applications and validate the proposed distinction between specific and generalized problematic Internet use. In addition to Internet gaming disorder, future studies should also focus on other highly addictive Internet applications, that is, chatting or social networking, regarding differential correlates of problematic use. © 2017 S. Karger AG, Basel.

  7. Chronic Stereotype Threat Is Associated With Mathematical Achievement on Representative Sample of Secondary Schoolgirls: The Role of Gender Identification, Working Memory, and Intellectual Helplessness

    Science.gov (United States)

    Bedyńska, Sylwia; Krejtz, Izabela; Sedek, Grzegorz

    2018-01-01

    Stereotype threat affects performance in many different groups across many different domains. Despite a large body of experimental research on situational stereotype threat, little attention has been paid to the consequences of repeated experience of stereotype threat. Using structural equation modeling on data from a representative sample of girls from secondary schools, the current research examined the relations of chronic stereotype threat with mathematical achievement, and effectiveness of working memory functions. Moving beyond past theory, this study examined a new mechanism by which chronic stereotype threat decreases school achievement – namely intellectual helplessness. We assumed that repeated experience of stereotype threat works as intellectual helplessness training. After the phase of cognitive mobilization, cognitive exhaustion appears, because the individual has no gain from intense cognitive effort. Corroborating previous research on acute stereotype threat, we demonstrated that chronic stereotype threat is negatively associated with mathematical achievement. Additionally, it was also associated with lower effectiveness of working memory functions, which seems to show depletion of working memory as an effect of chronic stereotype threat. The results also demonstrated that both mediational paths from chronic stereotype threat to mathematical achievement: through working memory depletion and through intellectual helplessness were significant but only for girls that were highly identified with their gender group. In sum, we extended a well-established model of acute stereotype threat to its chronic version and suggested a new mechanism of chronic stereotype threat, which involves intellectual helplessness. Implications for stereotype threat theory and educational practice are discussed. PMID:29666599

  8. Differences in symptom expression between unipolar and bipolar spectrum depression: Results from a nationally representative sample using item response theory (IRT).

    Science.gov (United States)

    Hoertel, Nicolas; Blanco, Carlos; Peyre, Hugo; Wall, Melanie M; McMahon, Kibby; Gorwood, Philip; Lemogne, Cédric; Limosin, Frédéric

    2016-11-01

    The inclusion of subsyndromal forms of bipolarity in the fifth edition of the DSM has major implications for the way in which we approach the diagnosis of individuals with depressive symptoms. The aim of the present study was to use methods based on item response theory (IRT) to examine whether, when equating for levels of depression severity, there are differences in the likelihood of reporting DSM-IV symptoms of major depressive episode (MDE) between subjects with and without a lifetime history of manic symptoms. We conducted these analyses using a large, nationally representative sample from the USA (n=34,653), the second wave of the National Epidemiologic Survey on Alcohol and Related Conditions. The items sadness, appetite disturbance and psychomotor symptoms were better indicators of depression severity in participants without a lifetime history of manic symptoms, in a clinically meaningful way. DSM-IV symptoms of MDE were substantially less informative in participants with a lifetime history of manic symptoms than in those without such history. Clinical information on DSM-IV depressive and manic symptoms was based on retrospective self-report The clinical presentation of depressive symptoms may substantially differ in individuals with and without a lifetime history of manic symptoms. These findings alert to the possibility of atypical symptomatic presentations among individuals with co-occurring symptoms or disorders and highlight the importance of continued research into specific pathophysiology differentiating unipolar and bipolar depression. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Openness, neuroticism, conscientiousness, and family health and aging concerns interact in the prediction of health-related Internet searches in a representative U.S. sample

    Directory of Open Access Journals (Sweden)

    Tim eBogg

    2014-04-01

    Full Text Available Recent estimates suggest 60 % of the U.S. adult population uses the Internet to find health-related information. The goal of the present study was to model health-related Internet searches as a function of an interdependent system of personality adaptation in the context of recent health and aging-related concerns. Assessments of background factors, Big Five personality traits, past-month health and aging-related concerns, and the frequency of past-month health-related Internet searches (via Google, Yahoo, AOL, Bing, or some other search engine were obtained from a representative U.S. sample (N = 1,015. Controlling for background factors, regression analyses showed more frequent health-related Internet searches were predicted by a drive for exploration and investigation (high openness, as well as alarm sensitivity (high openness and high neuroticism and an anticipatory inclination (high openness and high conscientiousness in the context of recent problems with aging parents and recent health concerns for a family member. Consistent with interdependent models of personality adaptation, as well as prior evidence for surrogate health-related Internet searches, the results suggest a personality process model of search behavior that is partially dependent upon dispositional levels of exploration, emotional stability, control, and health and aging concerns for family members.

  10. Openness, neuroticism, conscientiousness, and family health and aging concerns interact in the prediction of health-related Internet searches in a representative U.S. sample.

    Science.gov (United States)

    Bogg, Tim; Vo, Phuong T

    2014-01-01

    Recent estimates suggest 60% of the U.S. adult population uses the Internet to find health-related information. The goal of the present study was to model health-related Internet searches as a function of an interdependent system of personality adaptation in the context of recent health and aging-related concerns. Assessments of background factors, Big Five personality traits, past-month health and aging-related concerns, and the frequency of past-month health-related Internet searches (via Google, Yahoo, AOL, Bing, or some other search engine) were obtained from a representative U.S. sample (N = 1,015). Controlling for background factors, regression analyses showed more frequent health-related Internet searches were predicted by a drive for exploration and investigation (high openness), as well as alarm sensitivity (high openness and high neuroticism) and an anticipatory inclination (high openness and high conscientiousness) in the context of recent problems with aging parents and recent health concerns for a family member. Consistent with interdependent models of personality adaptation, as well as prior evidence for "surrogate" health-related Internet searches, the results suggest a personality process model of search behavior that is partially dependent upon dispositional levels of exploration, emotional stability, control, and health and aging concerns for family members.

  11. Clinician ratings of the Comprehensive Assessment of Psychopathic Personality (CAPP) in a representative sample of Spanish prison inmates: New validity evidence.

    Science.gov (United States)

    Flórez, Gerardo; Ferrer, Ventura; García, Luis S; Crespo, María R; Pérez, Manuel; Saíz, Pilar A; Cooke, David J

    2018-01-01

    The Comprehensive Assessment of Psychopathic Personality (CAPP) is a concept map of psychopathic personality disorder (PPD). The CAPP- Institutional Rating Scale (IRS) is a tool designed to assess CAPP symptoms in institutional settings. The CAPP contains 33 personality traits organized in six domains: attachment, behavioural, cognitive, dominance, emotional and self. Until now, much of the CAPP research has been conducted out of clinical, forensic and correctional settings using self-ratings. In the current study, the psychometric properties and construct validity of the CAPP-IRS were evaluated in a non-convenience sample of 204 Spanish convicts. Clinician ratings were employed. Participants had been imprisoned for at least 6 months at Pereiro de Aguiar Penitentiary. This group of inmates was heterogeneous with respect to type of official charges, and representative as all convicts interned for at least 6 months in this prison were screened for participation. Classical test theory indexes of reliability, correlations between CAPP items and domains and external correlations and structural analyses demonstrated that CAPP assessment is a solid and robust way of evaluating psychopathy in a correctional setting. Best fit was found for a three-factor model: attachment and emotional items associated with a callous and unemotional trait, dominance and self items associated with a pathological interpersonal style, and behavioural and residual items from other domains associated with impulsivity.

  12. Regular drinking may strengthen the beneficial influence of social support on depression: findings from a representative Israeli sample during a period of war and terrorism.

    Science.gov (United States)

    Kane, Jeremy C; Rapaport, Carmit; Zalta, Alyson K; Canetti, Daphna; Hobfoll, Stevan E; Hall, Brian J

    2014-07-01

    Social support is consistently associated with reduced risk of depression. Few studies have investigated how this relationship may be modified by alcohol use, the effects of which may be particularly relevant in traumatized populations in which rates of alcohol use are known to be high. In 2008 a representative sample of 1622 Jewish and Palestinian citizens in Israel were interviewed by phone at two time points during a period of ongoing terrorism and war threat. Two multivariable mixed effects regression models were estimated to measure the longitudinal association of social support from family and friends on depression symptoms. Three-way interaction terms between social support, alcohol use and time were entered into the models to test for effect modification. Findings indicated that increased family social support was associated with less depression symptomatology (p=Social support from friends was also associated with fewer depression symptoms (p=effect of social support was stronger for those who drank alcohol regularly than those who did not drink or drank rarely. These findings suggest that social support is a more important protective factor for depression among regular drinkers than among those who do not drink or drink rarely in the context of political violence. Additional research is warranted to determine whether these findings are stable in other populations and settings. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Frequency of Cannabis Use and Medical Cannabis Use Among Persons Living With HIV in the United States: Findings From a Nationally Representative Sample.

    Science.gov (United States)

    Pacek, Lauren R; Towe, Sheri L; Hobkirk, Andrea L; Nash, Denis; Goodwin, Renee D

    2018-04-01

    Little is known about cannabis use frequency, medical cannabis use, or correlates of use among persons living with HIV (PLWH) in United States nationally representative samples. Data came from 626 PLWH from the 2005-2015 National Survey on Drug Use and Health. Logistic regression identified characteristics associated with frequency of cannabis use. Chi-squares identified characteristics associated with medial cannabis use. Non-daily and daily cannabis use was reported by 26.9% and 8.0%. Greater perceived risk of cannabis use was negatively associated with daily and non-daily use. Younger age, substance use, and binge drinking were positively associated with non-daily cannabis use. Smoking and depression were associated with non-daily and daily use. One-quarter reported medical cannabis use. Medical users were more likely to be White, married, and nondrinkers. Cannabis use was common among PLWH. Findings help to differentiate between cannabis users based on frequency of use and medical versus recreational use.

  14. Chronic Stereotype Threat Is Associated With Mathematical Achievement on Representative Sample of Secondary Schoolgirls: The Role of Gender Identification, Working Memory, and Intellectual Helplessness

    Directory of Open Access Journals (Sweden)

    Sylwia Bedyńska

    2018-04-01

    Full Text Available Stereotype threat affects performance in many different groups across many different domains. Despite a large body of experimental research on situational stereotype threat, little attention has been paid to the consequences of repeated experience of stereotype threat. Using structural equation modeling on data from a representative sample of girls from secondary schools, the current research examined the relations of chronic stereotype threat with mathematical achievement, and effectiveness of working memory functions. Moving beyond past theory, this study examined a new mechanism by which chronic stereotype threat decreases school achievement – namely intellectual helplessness. We assumed that repeated experience of stereotype threat works as intellectual helplessness training. After the phase of cognitive mobilization, cognitive exhaustion appears, because the individual has no gain from intense cognitive effort. Corroborating previous research on acute stereotype threat, we demonstrated that chronic stereotype threat is negatively associated with mathematical achievement. Additionally, it was also associated with lower effectiveness of working memory functions, which seems to show depletion of working memory as an effect of chronic stereotype threat. The results also demonstrated that both mediational paths from chronic stereotype threat to mathematical achievement: through working memory depletion and through intellectual helplessness were significant but only for girls that were highly identified with their gender group. In sum, we extended a well-established model of acute stereotype threat to its chronic version and suggested a new mechanism of chronic stereotype threat, which involves intellectual helplessness. Implications for stereotype threat theory and educational practice are discussed.

  15. Chronic Stereotype Threat Is Associated With Mathematical Achievement on Representative Sample of Secondary Schoolgirls: The Role of Gender Identification, Working Memory, and Intellectual Helplessness.

    Science.gov (United States)

    Bedyńska, Sylwia; Krejtz, Izabela; Sedek, Grzegorz

    2018-01-01

    Stereotype threat affects performance in many different groups across many different domains. Despite a large body of experimental research on situational stereotype threat, little attention has been paid to the consequences of repeated experience of stereotype threat. Using structural equation modeling on data from a representative sample of girls from secondary schools, the current research examined the relations of chronic stereotype threat with mathematical achievement, and effectiveness of working memory functions. Moving beyond past theory, this study examined a new mechanism by which chronic stereotype threat decreases school achievement - namely intellectual helplessness. We assumed that repeated experience of stereotype threat works as intellectual helplessness training. After the phase of cognitive mobilization, cognitive exhaustion appears, because the individual has no gain from intense cognitive effort. Corroborating previous research on acute stereotype threat, we demonstrated that chronic stereotype threat is negatively associated with mathematical achievement. Additionally, it was also associated with lower effectiveness of working memory functions, which seems to show depletion of working memory as an effect of chronic stereotype threat. The results also demonstrated that both mediational paths from chronic stereotype threat to mathematical achievement: through working memory depletion and through intellectual helplessness were significant but only for girls that were highly identified with their gender group. In sum, we extended a well-established model of acute stereotype threat to its chronic version and suggested a new mechanism of chronic stereotype threat, which involves intellectual helplessness. Implications for stereotype threat theory and educational practice are discussed.

  16. Relationship between late-life depression and life stressors: large-scale cross-sectional study of a representative sample of the Japanese general population.

    Science.gov (United States)

    Kaji, Tatsuhiko; Mishima, Kazuo; Kitamura, Shingo; Enomoto, Minori; Nagase, Yukihiro; Li, Lan; Kaneita, Yoshitaka; Ohida, Takashi; Nishikawa, Toru; Uchiyama, Makoto

    2010-08-01

    The purpose of the present study was to clarify the relationship between late-life depression and daily life stress in a representative sample of 10 969 Japanese subjects. Data on 10 969 adults aged > or =50 who participated in the Active Survey of Health and Welfare in 2000, were analyzed. The self-administered questionnaire included items on 21 reasons for life stressors and the magnitude of stress, as well as the Japanese version of the Center for Epidemiologic Studies Depression Scale (CES-D). The relationship between the incidence of life stressors and mild-moderate (D(16)) and severe (D(26)) depressive symptoms was examined using logistic regression analysis. A total of 21.9% of subjects had D(16) symptoms, and 9.3% had D(26) symptoms. Further, increased age and being female were associated with more severe depressive state. Logistic regression analysis indicated that the strongest relationship between both the incidence of D(16) and D(26) symptoms and life stressors stemmed from 'having no one to talk to' (odds ratio = 3.3 and 5.0, respectively). Late-life depression was also associated with 'loss of purpose in life', 'separation/divorce', 'having nothing to do', 'health/illness/care of self', and 'debt'. There is a relationship between late-life depression and diminished social relationships, experiences involving loss of purpose in life or human relationships, and health problems in the Japanese general population.

  17. Risk and protective factors associated with speech and language impairment in a nationally representative sample of 4- to 5-year-old children.

    Science.gov (United States)

    Harrison, Linda J; McLeod, Sharynne

    2010-04-01

    To determine risk and protective factors for speech and language impairment in early childhood. Data are presented for a nationally representative sample of 4,983 children participating in the Longitudinal Study of Australian Children (described in McLeod & Harrison, 2009). Thirty-one child, parent, family, and community factors previously reported as being predictors of speech and language impairment were tested as predictors of (a) parent-rated expressive speech/language concern and (b) receptive language concern, (c) use of speech-language pathology services, and (d) low receptive vocabulary. Bivariate logistic regression analyses confirmed 29 of the identified factors. However, when tested concurrently with other predictors in multivariate analyses, only 19 remained significant: 9 for 2-4 outcomes and 10 for 1 outcome. Consistent risk factors were being male, having ongoing hearing problems, and having a more reactive temperament. Protective factors were having a more persistent and sociable temperament and higher levels of maternal well-being. Results differed by outcome for having an older sibling, parents speaking a language other than English, and parental support for children's learning at home. Identification of children requiring speech and language assessment requires consideration of the context of family life as well as biological and psychosocial factors intrinsic to the child.

  18. Sample Size Calculation: Inaccurate A Priori Assumptions for Nuisance Parameters Can Greatly Affect the Power of a Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Elsa Tavernier

    Full Text Available We aimed to examine the extent to which inaccurate assumptions for nuisance parameters used to calculate sample size can affect the power of a randomized controlled trial (RCT. In a simulation study, we separately considered an RCT with continuous, dichotomous or time-to-event outcomes, with associated nuisance parameters of standard deviation, success rate in the control group and survival rate in the control group at some time point, respectively. For each type of outcome, we calculated a required sample size N for a hypothesized treatment effect, an assumed nuisance parameter and a nominal power of 80%. We then assumed a nuisance parameter associated with a relative error at the design stage. For each type of outcome, we randomly drew 10,000 relative errors of the associated nuisance parameter (from empirical distributions derived from a previously published review. Then, retro-fitting the sample size formula, we derived, for the pre-calculated sample size N, the real power of the RCT, taking into account the relative error for the nuisance parameter. In total, 23%, 0% and 18% of RCTs with continuous, binary and time-to-event outcomes, respectively, were underpowered (i.e., the real power was 90%. Even with proper calculation of sample size, a substantial number of trials are underpowered or overpowered because of imprecise knowledge of nuisance parameters. Such findings raise questions about how sample size for RCTs should be determined.

  19. 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

  20. Characteristics of men with substance use disorder consequent to illicit drug use: comparison of a random sample and volunteers.

    Science.gov (United States)

    Reynolds, Maureen D; Tarter, Ralph E; Kirisci, Levent

    2004-09-06

    Men qualifying for substance use disorder (SUD) consequent to consumption of an illicit drug were compared according to recruitment method. It was hypothesized that volunteers would be more self-disclosing and exhibit more severe disturbances compared to randomly recruited subjects. Personal, demographic, family, social, substance use, psychiatric, and SUD characteristics of volunteers (N = 146) were compared to randomly recruited (N = 102) subjects. Volunteers had lower socioceconomic status, were more likely to be African American, and had lower IQ than randomly recruited subjects. Volunteers also evidenced greater social and family maladjustment and more frequently had received treatment for substance abuse. In addition, lower social desirability response bias was observed in the volunteers. SUD was not more severe in the volunteers; however, they reported a higher lifetime rate of opiate, diet, depressant, and analgesic drug use. Volunteers and randomly recruited subjects qualifying for SUD consequent to illicit drug use are similar in SUD severity but differ in terms of severity of psychosocial disturbance and history of drug involvement. The factors discriminating volunteers and randomly recruited subjects are well known to impact on outcome, hence they need to be considered in research design, especially when selecting a sampling strategy in treatment research.

  1. Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

    Science.gov (United States)

    Borak, T B

    1986-04-01

    Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

  2. Representing Development

    DEFF Research Database (Denmark)

    Representing Development presents the different social representations that have formed the idea of development in Western thinking over the past three centuries. Offering an acute perspective on the current state of developmental science and providing constructive insights into future pathways, ...

  3. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States.

    Directory of Open Access Journals (Sweden)

    Andreas Steimer

    Full Text Available Oscillations between high and low values of the membrane potential (UP and DOWN states respectively are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs of the exponential integrate and fire (EIF model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI. As we show, the EIF's exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron's ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing

  4. Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States.

    Science.gov (United States)

    Steimer, Andreas; Schindler, Kaspar

    2015-01-01

    Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI. As we show, the EIF's exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron's ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing computational

  5. Parameters, test criteria and fault assessment in random sampling of waste barrels from non-qualified processes

    International Nuclear Information System (INIS)

    Martens, B.R.

    1989-01-01

    In the context of random sampling tests, parameters are checked on the waste barrels and criteria are given on which these tests are based. Also, it is shown how faulty data on the properties of the waste or faulty waste barrels should be treated. To decide the extent of testing, the properties of the waste relevant to final storage are determined based on the conditioning process used. (DG) [de

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  7. Conditional estimation of exponential random graph models from snowball sampling designs

    NARCIS (Netherlands)

    Pattison, Philippa E.; Robins, Garry L.; Snijders, Tom A. B.; Wang, Peng

    2013-01-01

    A complete survey of a network in a large population may be prohibitively difficult and costly. So it is important to estimate models for networks using data from various network sampling designs, such as link-tracing designs. We focus here on snowball sampling designs, designs in which the members

  8. The concerned significant others of people with gambling problems in a national representative sample in Sweden - a 1 year follow-up study.

    Science.gov (United States)

    Svensson, Jessika; Romild, Ulla; Shepherdson, Emma

    2013-11-21

    Research into the impact of problem gambling on close social networks is scarce with the majority of studies only including help-seeking populations. To date only one study has examined concerned significant others (CSOs) from an epidemiological perspective and it did not consider gender. The aim of this study is to examine the health, social support, and financial situations of CSOs in a Swedish representative sample and to examine gender differences. A population study was conducted in Sweden in 2008/09 (n = 15,000, response rate 63%). Respondents were defined as CSOs if they reported that someone close to them currently or previously had problems with gambling. The group of CSOs was further examined in a 1-year follow up (weighted response rate 74% from the 8,165 respondents in the original sample). Comparisons were also made between those defined as CSOs only at baseline (47.7%, n = 554) and those defined as CSOs at both time points. In total, 18.2% of the population were considered CSOs, with no difference between women and men. Male and female CSOs experienced, to a large extent, similar problems including poor mental health, risky alcohol consumption, economic hardship, and arguments with those closest to them. Female CSOs reported less social support than other women and male CSOs had more legal problems and were more afraid of losing their jobs than other men. One year on, several problems remained even if some improvements were found. Both male and female CSOs reported more negative life events in the 1 year follow-up. Although some relationships are unknown, including between the CSOs and the individuals with gambling problems and the causal relationships between being a CSO and the range of associated problems, the results of this study indicate that gambling problems not only affect the gambling individual and their immediate close family but also the wider social network. A large proportion of the population can be defined as a CSO, half of whom are

  9. Differences in knowledge of dementia among older adults with normal cognition, mild cognitive impairment, and dementia: A representative nationwide sample of Korean elders.

    Science.gov (United States)

    Lee, Jun-Young; Park, Soowon; Kim, Ki Woong; Kwon, Ji Eyon; Park, Joon Hyuk; Kim, Moon Doo; Kim, Bong-Jo; Kim, Jeong Lan; Moon, Seok Woo; Bae, Jae Nam; Ryu, Seung-Ho; Yoon, Jong Chul; Lee, Nam-Jin; Lee, Dong Young; Lee, Dong Woo; Lee, Seok Bum; Lee, Jung Jae; Lee, Chang-Uk; Jhoo, Jin Hyeong; Cho, Maeng Je

    2016-01-01

    Lack of knowledge about a disease could impede early diagnosis and may lead to delays in seeking appropriate medical care. The aim of this study was to explore knowledge of dementia (KOD) and to find the determinants of KOD among three groups: older adults with normal cognition, mild cognitive impairment (MCI), and dementia. A representative nationwide sample of 6141 Korean elders aged 65 years or older participated in face-to-face interviews and answered 14 questions pertaining to general information, etiology, symptoms, and treatment of dementia. Stepwise multiple regressions and path analyses probed the relationships between various sociodemographic variables and KOD. The percentage of correct responses was only 62%. The item 'A person who remembers things that happened in the past does not have dementia' was answered correctly (false) by only 24.8-27% of the respondents in all groups. Older adults with normal cognition had higher KOD scores than those with MCI or dementia. In the normal-cognition group, KOD scores were higher among highly educated, younger, and literate women with no depression and a family history of dementia. In contrast with the determinants in the normal-cognition group, only the ability to read and write predicted KOD scores in the dementia group. Efforts to enhance KOD in elder adults are needed. Public education regarding the differences between dementia and healthy aging may increase KOD among normal elders and those with MCI. Among elders with dementia, educational materials that do not require literacy may be more helpful in increasing KOD with the aim of preventing treatment delay. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Paid employment and common mental disorders in 50-64-year olds: analysis of three cross-sectional nationally representative survey samples in 1993, 2000 and 2007.

    Science.gov (United States)

    Perera, G; Di Gessa, G; Corna, L M; Glaser, K; Stewart, R

    2017-08-24

    Associations between employment status and mental health are well recognised, but evidence is sparse on the relationship between paid employment and mental health in the years running up to statutory retirement ages using robust mental health measures. In addition, there has been no investigation into the stability over time in this relationship: an important consideration if survey findings are used to inform future policy. The aim of this study is to investigate the association between employment status and common mental disorder (CMD) in 50-64-year old residents in England and its stability over time, taking advantage of three national mental health surveys carried out over a 14-year period. Data were analysed from the British National Surveys of Psychiatric Morbidity of 1993, 2000 and 2007. Paid employment status was the primary exposure of interest and CMD the primary outcome - both ascertained identically in all three surveys (CMD from the revised Clinical Interview Schedule). Multivariable logistic regression models were used. The prevalence of CMD was higher in people not in paid employment across all survey years; however, this association was only present for non-employment related to poor health as an outcome and was not apparent in those citing other reasons for non-employment. Odds ratios for the association between non-employment due to ill health and CMD were 3.05 in 1993, 3.56 in 2000, and 2.80 in 2007, after adjustment for age, gender, marital status, education, social class, housing tenure, financial difficulties, smoking status, recent physical health consultation and activities of daily living impairment. The prevalence of CMD was higher in people not in paid employment for health reasons, but was not associated with non-employment for other reasons. Associations had been relatively stable in strength from 1993 to 2007 in those three cross-sectional nationally representative samples.

  11. Regular drinking may strengthen the beneficial influence of social support on depression: Findings from a representative Israeli sample during a period of war and terrorism

    Science.gov (United States)

    Kane, Jeremy C.; Rapaport, Carmit; Zalta, Alyson K.; Canetti, Daphna; Hobfoll, Stevan E.; Hall, Brian J.

    2016-01-01

    Background Social support is consistently associated with reduced risk of depression. Few studies have investigated how this relationship may be modified by alcohol use, the effects of which may be particularly relevant in traumatized populations in which rates of alcohol use are known to be high. Methods In 2008 a representative sample of 1622 Jewish and Palestinian citizens in Israel were interviewed by phone at two time points during a period of ongoing terrorism and war threat. Two multivariable mixed effects regression models were estimated to measure the longitudinal association of social support from family and friends on depression symptoms. Three-way interaction terms between social support, alcohol use and time were entered into the models to test for effect modification. Results Findings indicated that increased family social support was associated with less depression symptomatology (p=<.01); this relationship was modified by alcohol use and time (p=<.01). Social support from friends was also associated