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Sample records for missing binary outcome

  1. A simple method for analyzing data from a randomized trial with a missing binary outcome

    Directory of Open Access Journals (Sweden)

    Freedman Laurence S

    2003-05-01

    Full Text Available Abstract Background Many randomized trials involve missing binary outcomes. Although many previous adjustments for missing binary outcomes have been proposed, none of these makes explicit use of randomization to bound the bias when the data are not missing at random. Methods We propose a novel approach that uses the randomization distribution to compute the anticipated maximum bias when missing at random does not hold due to an unobserved binary covariate (implying that missingness depends on outcome and treatment group. The anticipated maximum bias equals the product of two factors: (a the anticipated maximum bias if there were complete confounding of the unobserved covariate with treatment group among subjects with an observed outcome and (b an upper bound factor that depends only on the fraction missing in each randomization group. If less than 15% of subjects are missing in each group, the upper bound factor is less than .18. Results We illustrated the methodology using data from the Polyp Prevention Trial. We anticipated a maximum bias under complete confounding of .25. With only 7% and 9% missing in each arm, the upper bound factor, after adjusting for age and sex, was .10. The anticipated maximum bias of .25 × .10 =.025 would not have affected the conclusion of no treatment effect. Conclusion This approach is easy to implement and is particularly informative when less than 15% of subjects are missing in each arm.

  2. A general method for handling missing binary outcome data in randomized controlled trials

    OpenAIRE

    Jackson, Dan; White, Ian R; Mason, Dan; Sutton, Stephen

    2014-01-01

    Aims The analysis of randomized controlled trials with incomplete binary outcome data is challenging. We develop a general method for exploring the impact of missing data in such trials, with a focus on abstinence outcomes. Design We propose a sensitivity analysis where standard analyses, which could include ‘missing = smoking’ and ‘last observation carried forward’, are embedded in a wider class of models. Setting We apply our general method to data from two smoking cessation trials. Partici...

  3. Comparison of population-averaged and cluster-specific models for the analysis of cluster randomized trials with missing binary outcomes: a simulation study

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    Ma Jinhui

    2013-01-01

    Full Text Available Abstracts Background The objective of this simulation study is to compare the accuracy and efficiency of population-averaged (i.e. generalized estimating equations (GEE and cluster-specific (i.e. random-effects logistic regression (RELR models for analyzing data from cluster randomized trials (CRTs with missing binary responses. Methods In this simulation study, clustered responses were generated from a beta-binomial distribution. The number of clusters per trial arm, the number of subjects per cluster, intra-cluster correlation coefficient, and the percentage of missing data were allowed to vary. Under the assumption of covariate dependent missingness, missing outcomes were handled by complete case analysis, standard multiple imputation (MI and within-cluster MI strategies. Data were analyzed using GEE and RELR. Performance of the methods was assessed using standardized bias, empirical standard error, root mean squared error (RMSE, and coverage probability. Results GEE performs well on all four measures — provided the downward bias of the standard error (when the number of clusters per arm is small is adjusted appropriately — under the following scenarios: complete case analysis for CRTs with a small amount of missing data; standard MI for CRTs with variance inflation factor (VIF 50. RELR performs well only when a small amount of data was missing, and complete case analysis was applied. Conclusion GEE performs well as long as appropriate missing data strategies are adopted based on the design of CRTs and the percentage of missing data. In contrast, RELR does not perform well when either standard or within-cluster MI strategy is applied prior to the analysis.

  4. The handling of missing binary data in language research

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    François Pichette

    2015-01-01

    Full Text Available Researchers are frequently confronted with unanswered questions or items on their questionnaires and tests, due to factors such as item difficulty, lack of testing time, or participant distraction. This paper first presents results from a poll confirming previous claims (Rietveld & van Hout, 2006; Schafer & Gra- ham, 2002 that data replacement and deletion methods are common in research. Language researchers declared that when faced with missing answers of the yes/no type (that translate into zero or one in data tables, the three most common solutions they adopt are to exclude the participant’s data from the analyses, to leave the square empty, or to fill in with zero, as for an incorrect answer. This study then examines the impact on Cronbach’s α of five types of data insertion, using simulated and actual data with various numbers of participants and missing percentages. Our analyses indicate that the three most common methods we identified among language researchers are the ones with the greatest impact  n Cronbach's α coefficients; in other words, they are the least desirable solutions to the missing data problem. On the basis of our results, we make recommendations for language researchers concerning the best way to deal with missing data. Given that none of the most common simple methods works properly, we suggest that the missing data be replaced either by the item’s mean or by the participants’ overall mean to provide a better, more accurate image of the instrument’s internal consistency.

  5. Patterns and Outcome of Missed Injuries in Egyptians Polytrauma Patients

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    Adel Hamed Elbaih

    2018-01-01

    Full Text Available Introduction: “polytrauma” patients are higher risk of complications and death than the summation of expected mortality and morbidity of their individual injuries. The ideal goal in trauma resuscitation care is to identify and treat all injuries. With clinical and technological advanced imaging available for diagnosis and treatment of traumatic patients, missed injuries still significant affect modern trauma services and its outcome. Aim: to improve outcome and determine the incidence and nature of missed injuries in polytrauma patients. Methods: the study is a cross-sectional, prospective study included 600 polytraumatized patients admitted in Suez Canal University Hospital. Firstly assessed and treated accordingly to Advanced Trauma Life Support (ATLS guidelines and treat the life threading conditions if present with follow-up short outcome for 28 days. Results: The most common precipitate factor for missed injuries in my study was clinical evaluation error due to Inadequate diagnostic workup in 42.9%. And the second risk factor was Deficiency in Physical Examination in 35.7%. Lastly Incomplete assessment due to patient instability in 10.7% and incorrect interpretation of imaging10.7%.low rates of missed injuries (40.8% in patients arriving during the day compared with (59.2% of night arrivals. Conclusion: the incidence of missed injuries in the study is 9.0 % which is still high compared to many trauma centers. And mostly increase the period of stay in the hospital and affect the outcome of polytrauma patients.

  6. Corrected ROC analysis for misclassified binary outcomes.

    Science.gov (United States)

    Zawistowski, Matthew; Sussman, Jeremy B; Hofer, Timothy P; Bentley, Douglas; Hayward, Rodney A; Wiitala, Wyndy L

    2017-06-15

    Creating accurate risk prediction models from Big Data resources such as Electronic Health Records (EHRs) is a critical step toward achieving precision medicine. A major challenge in developing these tools is accounting for imperfect aspects of EHR data, particularly the potential for misclassified outcomes. Misclassification, the swapping of case and control outcome labels, is well known to bias effect size estimates for regression prediction models. In this paper, we study the effect of misclassification on accuracy assessment for risk prediction models and find that it leads to bias in the area under the curve (AUC) metric from standard ROC analysis. The extent of the bias is determined by the false positive and false negative misclassification rates as well as disease prevalence. Notably, we show that simply correcting for misclassification while building the prediction model is not sufficient to remove the bias in AUC. We therefore introduce an intuitive misclassification-adjusted ROC procedure that accounts for uncertainty in observed outcomes and produces bias-corrected estimates of the true AUC. The method requires that misclassification rates are either known or can be estimated, quantities typically required for the modeling step. The computational simplicity of our method is a key advantage, making it ideal for efficiently comparing multiple prediction models on very large datasets. Finally, we apply the correction method to a hospitalization prediction model from a cohort of over 1 million patients from the Veterans Health Administrations EHR. Implementations of the ROC correction are provided for Stata and R. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  7. Gravitational waves from binary supermassive black holes missing in pulsar observations.

    Science.gov (United States)

    Shannon, R M; Ravi, V; Lentati, L T; Lasky, P D; Hobbs, G; Kerr, M; Manchester, R N; Coles, W A; Levin, Y; Bailes, M; Bhat, N D R; Burke-Spolaor, S; Dai, S; Keith, M J; Osłowski, S; Reardon, D J; van Straten, W; Toomey, L; Wang, J-B; Wen, L; Wyithe, J S B; Zhu, X-J

    2015-09-25

    Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems would modulate the arrival times of pulses from radio pulsars. Using observations of millisecond pulsars obtained with the Parkes radio telescope, we constrained the characteristic amplitude of this background, A(c,yr), to be gravitational waves. Copyright © 2015, American Association for the Advancement of Science.

  8. Missed losses loom larger than missed gains: Electrodermal reactivity to decision choices and outcomes in a gambling task.

    Science.gov (United States)

    Wu, Yin; Van Dijk, Eric; Aitken, Mike; Clark, Luke

    2016-04-01

    Loss aversion is a defining characteristic of prospect theory, whereby responses are stronger to losses than to equivalently sized gains (Kahneman & Tversky Econometrica, 47, 263-291, 1979). By monitoring electrodermal activity (EDA) during a gambling task, in this study we examined physiological activity during risky decisions, as well as to both obtained (e.g., gains and losses) and counterfactual (e.g., narrowly missed gains and losses) outcomes. During the bet selection phase, EDA increased linearly with bet size, highlighting the role of somatic signals in decision-making under uncertainty in a task without any learning requirement. Outcome-related EDA scaled with the magnitudes of monetary wins and losses, and losses had a stronger impact on EDA than did equivalently sized wins. Narrowly missed wins (i.e., near-wins) and narrowly missed losses (i.e., near-losses) also evoked EDA responses, and the change of EDA as a function of the size of the missed outcome was modestly greater for near-losses than for near-wins, suggesting that near-losses have more impact on subjective value than do near-wins. Across individuals, the slope for choice-related EDA (as a function of bet size) correlated with the slope for outcome-related EDA as a function of both the obtained and counterfactual outcome magnitudes, and these correlations were stronger for loss and near-loss conditions than for win and near-win conditions. Taken together, these asymmetrical EDA patterns to objective wins and losses, as well as to near-wins and near-losses, provide a psychophysiological instantiation of the value function curve in prospect theory, which is steeper in the negative than in the positive domain.

  9. Estimation of response from longitudinal binary data with nonignorable missing values in migraine trials

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    Fang Fang

    2016-12-01

    Full Text Available In migraine trials pain relief responses from a headache at specific time points and sustained pain relief response over a period of time are important efficacy measures. When there are missing records of individual time point pain scores and/or headache recurrences during a migraine trial, the common approach used in practice to estimate the sustained response is statistically inconsistent even if the data are missing completely at random. Methods dealing with nonignorable longitudinal missing data usually assume certain models for the missing mechanism which can not be checked as they involve unobserved data. Taking advantage of the specific definition of the ‘sustained pain relief’ response, we propose two estimating methods based on intuitive imputation, which do not require model assumptions on the missing probability or specification of the correlation structure among the longitudinal observations. The consistency of the proposed methods is discussed in theory and their empirical performances are assessed through intensive simulation studies. The simulation results show that the proposed methods perform well in terms of reducing bias and mean square error except in several extreme cases which are unlikely to happen in real trials. The application of the proposed methods is illustrated in a real data analysis.

  10. Missing paternal demographics: A novel indicator for identifying high risk population of adverse pregnancy outcomes

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    Wen Shi

    2004-11-01

    Full Text Available Abstract Background One of every 6 United Status birth certificates contains no information on fathers. There might be important differences in the pregnancy outcomes between mothers with versus those without partner information. The object of this study was to assess whether and to what extent outcomes in pregnant women who did not have partner information differ from those who had. Methods We carried out a population-based retrospective cohort study based on the registry data in the United States for the period of 1995–1997, which was a matched multiple birth file (only twins were included in the current analysis. We divided the study subjects into three groups according to the availability of partner information: available, partly missing, and totally missing. We compared the distribution of maternal characteristics, maternal morbidity, labor and delivery complications, obstetric interventions, preterm birth, fetal growth restriction, low birth weight, congenital anomalies, fetal death, neonatal death, post-neonatal death, and neonatal morbidity among three study groups. Results There were 304466 twins included in our study. Mothers whose partner's information was partly missing and (especially totally missing tended to be younger, of black race, unmarried, with less education, smoking cigarette during pregnancy, and with inadequate prenatal care. The rates of preterm birth, fetal growth restriction, low birth weight, Apgar score Conclusions Mothers whose partner's information was partly and (especially totally missing are at higher risk of adverse pregnant outcomes, and clinicians and public health workers should be alerted to this important social factor.

  11. Implicit Valuation of the Near-Miss is Dependent on Outcome Context.

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    Banks, Parker J; Tata, Matthew S; Bennett, Patrick J; Sekuler, Allison B; Gruber, Aaron J

    2018-03-01

    Gambling studies have described a "near-miss effect" wherein the experience of almost winning increases gambling persistence. The near-miss has been proposed to inflate the value of preceding actions through its perceptual similarity to wins. We demonstrate here, however, that it acts as a conditioned stimulus to positively or negatively influence valuation, dependent on reward expectation and cognitive engagement. When subjects are asked to choose between two simulated slot machines, near-misses increase valuation of machines with a low payout rate, whereas they decrease valuation of high payout machines. This contextual effect impairs decisions and persists regardless of manipulations to outcome feedback or financial incentive provided for good performance. It is consistent with proposals that near-misses cause frustration when wins are expected, and we propose that it increases choice stochasticity and overrides avoidance of low-valued options. Intriguingly, the near-miss effect disappears when subjects are required to explicitly value machines by placing bets, rather than choosing between them. We propose that this task increases cognitive engagement and recruits participation of brain regions involved in cognitive processing, causing inhibition of otherwise dominant systems of decision-making. Our results reveal that only implicit, rather than explicit strategies of decision-making are affected by near-misses, and that the brain can fluidly shift between these strategies according to task demands.

  12. Missing continuous outcomes under covariate dependent missingness in cluster randomised trials.

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    Hossain, Anower; Diaz-Ordaz, Karla; Bartlett, Jonathan W

    2017-06-01

    Attrition is a common occurrence in cluster randomised trials which leads to missing outcome data. Two approaches for analysing such trials are cluster-level analysis and individual-level analysis. This paper compares the performance of unadjusted cluster-level analysis, baseline covariate adjusted cluster-level analysis and linear mixed model analysis, under baseline covariate dependent missingness in continuous outcomes, in terms of bias, average estimated standard error and coverage probability. The methods of complete records analysis and multiple imputation are used to handle the missing outcome data. We considered four scenarios, with the missingness mechanism and baseline covariate effect on outcome either the same or different between intervention groups. We show that both unadjusted cluster-level analysis and baseline covariate adjusted cluster-level analysis give unbiased estimates of the intervention effect only if both intervention groups have the same missingness mechanisms and there is no interaction between baseline covariate and intervention group. Linear mixed model and multiple imputation give unbiased estimates under all four considered scenarios, provided that an interaction of intervention and baseline covariate is included in the model when appropriate. Cluster mean imputation has been proposed as a valid approach for handling missing outcomes in cluster randomised trials. We show that cluster mean imputation only gives unbiased estimates when missingness mechanism is the same between the intervention groups and there is no interaction between baseline covariate and intervention group. Multiple imputation shows overcoverage for small number of clusters in each intervention group.

  13. Randomized trials, generalizability, and meta-analysis: Graphical insights for binary outcomes

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    Kramer Barnett S

    2003-06-01

    Full Text Available Abstract Background Randomized trials stochastically answer the question. "What would be the effect of treatment on outcome if one turned back the clock and switched treatments in the given population?" Generalizations to other subjects are reliable only if the particular trial is performed on a random sample of the target population. By considering an unobserved binary variable, we graphically investigate how randomized trials can also stochastically answer the question, "What would be the effect of treatment on outcome in a population with a possibly different distribution of an unobserved binary baseline variable that does not interact with treatment in its effect on outcome?" Method For three different outcome measures, absolute difference (DIF, relative risk (RR, and odds ratio (OR, we constructed a modified BK-Plot under the assumption that treatment has the same effect on outcome if either all or no subjects had a given level of the unobserved binary variable. (A BK-Plot shows the effect of an unobserved binary covariate on a binary outcome in two treatment groups; it was originally developed to explain Simpsons's paradox. Results For DIF and RR, but not OR, the BK-Plot shows that the estimated treatment effect is invariant to the fraction of subjects with an unobserved binary variable at a given level. Conclusion The BK-Plot provides a simple method to understand generalizability in randomized trials. Meta-analyses of randomized trials with a binary outcome that are based on DIF or RR, but not OR, will avoid bias from an unobserved covariate that does not interact with treatment in its effect on outcome.

  14. Perinatal outcome and near-miss morbidity between placenta previa versus abruptio placentae

    International Nuclear Information System (INIS)

    Siddique, S.A.; Tariq, G.; Sheikh, A.; Hussain, F.S.U.; Memon, K.A.

    2010-01-01

    To compare perinatal outcome and near-miss morbidities between placenta previa versus abruptio placentae in patients of antepartum haemorrhage (APH). Patients with APH diagnosed as placenta previa and abruptio placentae who delivered after 24 weeks of regnancy were selected from labour room. Outcome measures were birth weight, neonatal intensive care admission, stillbirth, perinatal mortality rates, near-miss, surgical intensive care admission, postpartum haemorrhage, hysterectomy, massive transfusion, renal failure, coagulopathy and maternal death. Stillbirth was defined as a fetus weighing greater or equal to 500 gm showing no sign of life after birth. Near-miss was defined as severe organ dysfunction which if not treated appropriately, could result in death. Descriptive statistics were calculated and chi-square was applied with significance level < 0.05. Stillbirths and perinatal mortality rates were significantly higher in abruptio placentae, 52.97% versus 18.18% and 534/1000 versus 230/1000 (p < 0.01). Near-miss cases were also significantly higher in abruptio placentae, 22.27%. Verus 11.18% (p < 0.01). Hypovolemic shock and coagulation failure were also significantly higher in abruptio placentae (p < 0.05). (author)

  15. A Statistical Model for Misreported Binary Outcomes in Clustered RCTs of Education Interventions

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    Schochet, Peter Z.

    2013-01-01

    In education randomized control trials (RCTs), the misreporting of student outcome data could lead to biased estimates of average treatment effects (ATEs) and their standard errors. This article discusses a statistical model that adjusts for misreported binary outcomes for two-level, school-based RCTs, where it is assumed that misreporting could…

  16. The missing GeV γ-ray binary: searching for HESS J0632+057 with Fermi-LAT

    NARCIS (Netherlands)

    Caliandro, G.A.; Hill, A.B.; Torres, D.F.; Hadasch, D.; Ray, P.; Abdo, A.; Hessels, J.W.T.; Ridolfi, A.; Possenti, A.; Burgay, M.; Rea, N.; Tam, P.H.T.; Dubois, R.; Dubus, G.; Glanzman, T.; Jogler, T.

    2013-01-01

    The very high energy (VHE; >100 GeV) source HESS J0632+057 has been recently confirmed as a γ-ray binary, a subclass of the high-mass X-ray binary population, through the detection of an orbital period of 321 d. We performed a deep search for the emission of HESS J0632+057 in the GeV energy range

  17. Outcome measures based on classification performance fail to predict the intelligibility of binary-masked speech

    DEFF Research Database (Denmark)

    Kressner, Abigail Anne; May, Tobias; Rozell, Christopher J.

    2016-01-01

    To date, the most commonly used outcome measure for assessing ideal binary mask estimation algorithms is based on the difference between the hit rate and the false alarm rate (H-FA). Recently, the error distribution has been shown to substantially affect intelligibility. However, H-FA treats each...... evaluations should not be made solely on the basis of these metrics....

  18. Increased Urge to Gamble Following Near-Miss Outcomes May Drive Purchasing Behaviour in Scratch Card Gambling.

    Science.gov (United States)

    Stange, Madison; Graydon, Candice; Dixon, Mike J

    2017-09-01

    Previous research into scratch card gambling has highlighted the effects of these games on players' arousal and affective states. Specifically, near-miss outcomes in scratch cards (uncovering 2 of 3 needed jackpot symbols) have been associated with high levels of physiological and subjective arousal and negative emotional evaluations, including increased frustration. We sought to extend this research by examining whether near-misses prompted increases in gambling urge, and the subsequent purchasing of additional scratch cards. Participants played two scratch cards with varying outcomes with half of the sample experiencing a near-miss for the jackpot prize, and the other half experiencing a regular loss. Players rated their urge to continue gambling after each game outcome, and following the initial playing phase, were then able to use their winnings to purchase additional cards. Our results indicated that near-misses increased the urge to gamble significantly more than regular losses, and urge to gamble in the near-miss group was significantly correlated with purchasing at least one additional card. Although some players in the loss group purchased another card, there was no correlation between urge to gamble and purchasing in this group. Additionally, participants in the near-miss group who purchased additional cards reported higher levels of urge than those who did not purchase more cards. This was not true for the loss group: participants who experienced solely losing outcomes reported similar levels of urge regardless of whether or not they purchased more scratch cards. Despite near-misses' objective status as monetary losses, the increased urge that follows near-miss outcomes may translate into further scratch card gambling for a subset of individuals .

  19. Causal analysis of ordinal treatments and binary outcomes under truncation by death.

    Science.gov (United States)

    Wang, Linbo; Richardson, Thomas S; Zhou, Xiao-Hua

    2017-06-01

    It is common that in multi-arm randomized trials, the outcome of interest is "truncated by death," meaning that it is only observed or well-defined conditioning on an intermediate outcome. In this case, in addition to pairwise contrasts, the joint inference for all treatment arms is also of interest. Under a monotonicity assumption we present methods for both pairwise and joint causal analyses of ordinal treatments and binary outcomes in presence of truncation by death. We illustrate via examples the appropriateness of our assumptions in different scientific contexts.

  20. Sensitivity analysis for missing dichotomous outcome data in multi-visit randomized clinical trial with randomization-based covariance adjustment.

    Science.gov (United States)

    Li, Siying; Koch, Gary G; Preisser, John S; Lam, Diana; Sanchez-Kam, Matilde

    2017-01-01

    Dichotomous endpoints in clinical trials have only two possible outcomes, either directly or via categorization of an ordinal or continuous observation. It is common to have missing data for one or more visits during a multi-visit study. This paper presents a closed form method for sensitivity analysis of a randomized multi-visit clinical trial that possibly has missing not at random (MNAR) dichotomous data. Counts of missing data are redistributed to the favorable and unfavorable outcomes mathematically to address possibly informative missing data. Adjusted proportion estimates and their closed form covariance matrix estimates are provided. Treatment comparisons over time are addressed with Mantel-Haenszel adjustment for a stratification factor and/or randomization-based adjustment for baseline covariables. The application of such sensitivity analyses is illustrated with an example. An appendix outlines an extension of the methodology to ordinal endpoints.

  1. The True Ultracool Binary Fraction Using Spectral Binaries

    Science.gov (United States)

    Bardalez Gagliuffi, Daniella; Burgasser, Adam J.; Schmidt, Sarah J.; Gagné, Jonathan; Faherty, Jacqueline K.; Cruz, Kelle; Gelino, Chris

    2018-01-01

    Brown dwarfs bridge the gap between stars and giant planets. While the essential mechanisms governing their formation are not well constrained, binary statistics are a direct outcome of the formation process, and thus provide a means to test formation theories. Observational constraints on the brown dwarf binary fraction place it at 10 ‑ 20%, dominated by imaging studies (85% of systems) with the most common separation at 4 AU. This coincides with the resolution limit of state-of-the-art imaging techniques, suggesting that the binary fraction is underestimated. We have developed a separation-independent method to identify and characterize tightly-separated (dwarfs as spectral binaries by identifying traces of methane in the spectra of late-M and early-L dwarfs. Imaging follow-up of 17 spectral binaries yielded 3 (18%) resolved systems, corroborating the observed binary fraction, but 5 (29%) known binaries were missed, reinforcing the hypothesis that the short-separation systems are undercounted. In order to find the true binary fraction of brown dwarfs, we have compiled a volume-limited, spectroscopic sample of M7-L5 dwarfs and searched for T dwarf companions. In the 25 pc volume, 4 candidates were found, three of which are already confirmed, leading to a spectral binary fraction of 0.95 ± 0.50%, albeit for a specific combination of spectral types. To extract the true binary fraction and determine the biases of the spectral binary method, we have produced a binary population simulation based on different assumptions of the mass function, age distribution, evolutionary models and mass ratio distribution. Applying the correction fraction resulting from this method to the observed spectral binary fraction yields a true binary fraction of 27 ± 4%, which is roughly within 1σ of the binary fraction obtained from high resolution imaging studies, radial velocity and astrometric monitoring. This method can be extended to identify giant planet companions to young brown

  2. Joint analysis of binary and quantitative traits with data sharing and outcome-dependent sampling.

    Science.gov (United States)

    Zheng, Gang; Wu, Colin O; Kwak, Minjung; Jiang, Wenhua; Joo, Jungnam; Lima, Joao A C

    2012-04-01

    We study the analysis of a joint association between a genetic marker with both binary (case-control) and quantitative (continuous) traits, where the quantitative trait values are only available for the cases due to data sharing and outcome-dependent sampling. Data sharing becomes common in genetic association studies, and the outcome-dependent sampling is the consequence of data sharing, under which a phenotype of interest is not measured for some subgroup. The trend test (or Pearson's test) and F-test are often, respectively, used to analyze the binary and quantitative traits. Because of the outcome-dependent sampling, the usual F-test can be applied using the subgroup with the observed quantitative traits. We propose a modified F-test by also incorporating the genotype frequencies of the subgroup whose traits are not observed. Further, a combination of this modified F-test and Pearson's test is proposed by Fisher's combination of their P-values as a joint analysis. Because of the correlation of the two analyses, we propose to use a Gamma (scaled chi-squared) distribution to fit the asymptotic null distribution for the joint analysis. The proposed modified F-test and the joint analysis can also be applied to test single trait association (either binary or quantitative trait). Through simulations, we identify the situations under which the proposed tests are more powerful than the existing ones. Application to a real dataset of rheumatoid arthritis is presented. © 2012 Wiley Periodicals, Inc.

  3. A Two-Step Approach for Analysis of Nonignorable Missing Outcomes in Longitudinal Regression: an Application to Upstate KIDS Study.

    Science.gov (United States)

    Liu, Danping; Yeung, Edwina H; McLain, Alexander C; Xie, Yunlong; Buck Louis, Germaine M; Sundaram, Rajeshwari

    2017-09-01

    Imperfect follow-up in longitudinal studies commonly leads to missing outcome data that can potentially bias the inference when the missingness is nonignorable; that is, the propensity of missingness depends on missing values in the data. In the Upstate KIDS Study, we seek to determine if the missingness of child development outcomes is nonignorable, and how a simple model assuming ignorable missingness would compare with more complicated models for a nonignorable mechanism. To correct for nonignorable missingness, the shared random effects model (SREM) jointly models the outcome and the missing mechanism. However, the computational complexity and lack of software packages has limited its practical applications. This paper proposes a novel two-step approach to handle nonignorable missing outcomes in generalized linear mixed models. We first analyse the missing mechanism with a generalized linear mixed model and predict values of the random effects; then, the outcome model is fitted adjusting for the predicted random effects to account for heterogeneity in the missingness propensity. Extensive simulation studies suggest that the proposed method is a reliable approximation to SREM, with a much faster computation. The nonignorability of missing data in the Upstate KIDS Study is estimated to be mild to moderate, and the analyses using the two-step approach or SREM are similar to the model assuming ignorable missingness. The two-step approach is a computationally straightforward method that can be conducted as sensitivity analyses in longitudinal studies to examine violations to the ignorable missingness assumption and the implications relative to health outcomes. © 2017 John Wiley & Sons Ltd.

  4. A SEARCH FOR VERY HIGH ENERGY GAMMA RAYS FROM THE MISSING LINK BINARY PULSAR J1023+0038 WITH VERITAS

    Energy Technology Data Exchange (ETDEWEB)

    Aliu, E. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Archer, A.; Buckley, J. H.; Bugaev, V. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W.; Cerruti, M. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Biteau, J. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Buchovecky, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Byrum, K. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Cardenzana, J. V; Dickinson, H. J.; Eisch, J. D. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Chen, X. [Institute of Physics and Astronomy, University of Potsdam, D-14476 Potsdam-Golm (Germany); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Cui, W.; Feng, Q. [Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 (United States); Falcone, A., E-mail: ester.aliu.fuste@gmail.com, E-mail: gtrichards@gatech.edu, E-mail: masha.chernyakova@dcu.ie, E-mail: malloryr@gmail.com [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); and others

    2016-11-10

    The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259–63/LS 2883, making it an ideal candidate for the study of high-energy nonthermal emission. It has been the subject of multiwavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high energy (VHE) gamma-ray observations carried out by the Very Energetic Radiation Imaging Telescope Array System before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that VHE gamma rays are produced via an inverse Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than ∼2 G before the disappearance of the radio pulsar and greater than ∼10 G afterward.

  5. A systematic review and development of a classification framework for factors associated with missing patient-reported outcome data.

    Science.gov (United States)

    Palmer, Michael J; Mercieca-Bebber, Rebecca; King, Madeleine; Calvert, Melanie; Richardson, Harriet; Brundage, Michael

    2018-02-01

    Missing patient-reported outcome data can lead to biased results, to loss of power to detect between-treatment differences, and to research waste. Awareness of factors may help researchers reduce missing patient-reported outcome data through study design and trial processes. The aim was to construct a Classification Framework of factors associated with missing patient-reported outcome data in the context of comparative studies. The first step in this process was informed by a systematic review. Two databases (MEDLINE and CINAHL) were searched from inception to March 2015 for English articles. Inclusion criteria were (a) relevant to patient-reported outcomes, (b) discussed missing data or compliance in prospective medical studies, and (c) examined predictors or causes of missing data, including reasons identified in actual trial datasets and reported on cover sheets. Two reviewers independently screened titles and abstracts. Discrepancies were discussed with the research team prior to finalizing the list of eligible papers. In completing the systematic review, four particular challenges to synthesizing the extracted information were identified. To address these challenges, operational principles were established by consensus to guide the development of the Classification Framework. A total of 6027 records were screened. In all, 100 papers were eligible and included in the review. Of these, 57% focused on cancer, 23% did not specify disease, and 20% reported for patients with a variety of non-cancer conditions. In total, 40% of the papers offered a descriptive analysis of possible factors associated with missing data, but some papers used other methods. In total, 663 excerpts of text (units), each describing a factor associated with missing patient-reported outcome data, were extracted verbatim. Redundant units were identified and sequestered. Similar units were grouped, and an iterative process of consensus among the investigators was used to reduce these units to a

  6. Reporting and Handling Missing Outcome Data in Mental Health: A Systematic Review of Cochrane Systematic Reviews and Meta-Analyses

    Science.gov (United States)

    Spineli, Loukia M.; Pandis, Nikolaos; Salanti, Georgia

    2015-01-01

    Objectives: The purpose of the study was to provide empirical evidence about the reporting of methodology to address missing outcome data and the acknowledgement of their impact in Cochrane systematic reviews in the mental health field. Methods: Systematic reviews published in the Cochrane Database of Systematic Reviews after January 1, 2009 by…

  7. Quantifying relative importance: Computing standardized effects in models with binary outcomes

    Science.gov (United States)

    Grace, James B.; Johnson, Darren; Lefcheck, Jonathan S.; Byrnes, Jarrett E.K.

    2018-01-01

    Scientists commonly ask questions about the relative importances of processes, and then turn to statistical models for answers. Standardized coefficients are typically used in such situations, with the goal being to compare effects on a common scale. Traditional approaches to obtaining standardized coefficients were developed with idealized Gaussian variables in mind. When responses are binary, complications arise that impact standardization methods. In this paper, we review, evaluate, and propose new methods for standardizing coefficients from models that contain binary outcomes. We first consider the interpretability of unstandardized coefficients and then examine two main approaches to standardization. One approach, which we refer to as the Latent-Theoretical or LT method, assumes that underlying binary observations there exists a latent, continuous propensity linearly related to the coefficients. A second approach, which we refer to as the Observed-Empirical or OE method, assumes responses are purely discrete and estimates error variance empirically via reference to a classical R2 estimator. We also evaluate the standard formula for calculating standardized coefficients based on standard deviations. Criticisms of this practice have been persistent, leading us to propose an alternative formula that is based on user-defined “relevant ranges”. Finally, we implement all of the above in an open-source package for the statistical software R.

  8. Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention

    OpenAIRE

    Nguyen, Trang Quynh; Webb-Vargas, Yenny; Koning, Ina M.; Stuart, Elizabeth A.

    2016-01-01

    We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation...

  9. The effect of maternal near miss on adverse infant nutritional outcomes

    Directory of Open Access Journals (Sweden)

    Dulce M. Zanardi

    Full Text Available OBJECTIVES: To evaluate the association between self-reported maternal near miss and adverse nutritional status in children under one year of age. METHODS: This study is a secondary analysis of a study in which women who took their children under one year of age to the national vaccine campaign were interviewed. The self-reported condition of maternal near miss used the criteria of Intensive Care Unit admission; eclampsia; blood transfusion and hysterectomy; and their potential associations with any type of nutritional disorder in children, including deficits in weight-for-age, deficits in height-for-age, obesity and breastfeeding. The rates of near miss for the country, regions and states were initially estimated. The relative risks of infant adverse nutritional status according to near miss and maternal/childbirth characteristics were estimated with their 95% CIs using bivariate and multiple analyses. RESULTS: The overall prevalence of near miss was 2.9% and was slightly higher for the Legal Amazon than for other regions. No significant associations were found with nutritional disorders in children. Only a 12% decrease in overall maternal breastfeeding was associated with near miss. Living in the countryside and child over 6 months of age increased the risk of altered nutritional status by approximately 15%, while female child gender decreased this risk by 30%. Maternal near miss was not associated with an increased risk of any alteration in infant nutritional status. CONCLUSIONS: There was no association between maternal near miss and altered nutritional status in children up to one year of age. The risk of infant adverse nutritional status was greater in women living in the countryside, for children over 6 months of age and for male gender.

  10. Meta-analysis of studies with bivariate binary outcomes: a marginal beta-binomial model approach.

    Science.gov (United States)

    Chen, Yong; Hong, Chuan; Ning, Yang; Su, Xiao

    2016-01-15

    When conducting a meta-analysis of studies with bivariate binary outcomes, challenges arise when the within-study correlation and between-study heterogeneity should be taken into account. In this paper, we propose a marginal beta-binomial model for the meta-analysis of studies with binary outcomes. This model is based on the composite likelihood approach and has several attractive features compared with the existing models such as bivariate generalized linear mixed model (Chu and Cole, 2006) and Sarmanov beta-binomial model (Chen et al., 2012). The advantages of the proposed marginal model include modeling the probabilities in the original scale, not requiring any transformation of probabilities or any link function, having closed-form expression of likelihood function, and no constraints on the correlation parameter. More importantly, because the marginal beta-binomial model is only based on the marginal distributions, it does not suffer from potential misspecification of the joint distribution of bivariate study-specific probabilities. Such misspecification is difficult to detect and can lead to biased inference using currents methods. We compare the performance of the marginal beta-binomial model with the bivariate generalized linear mixed model and the Sarmanov beta-binomial model by simulation studies. Interestingly, the results show that the marginal beta-binomial model performs better than the Sarmanov beta-binomial model, whether or not the true model is Sarmanov beta-binomial, and the marginal beta-binomial model is more robust than the bivariate generalized linear mixed model under model misspecifications. Two meta-analyses of diagnostic accuracy studies and a meta-analysis of case-control studies are conducted for illustration. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Multiple congenitally missing teeth: treatment outcome with autologous transplantation and orthodontic space closure.

    Science.gov (United States)

    Fiorentino, Giuseppe; Vecchione, Pietro

    2007-11-01

    Treatment for patients with congenitally missing teeth can be challenging. The treatment options include retaining the deciduous teeth, extracting the deciduous teeth and allowing the space to close spontaneously, implant replacement, autotransplantation, prosthetic replacement, and orthodontic space closure. Autologous transplantation and space closure with orthodontic appliances are demonstrated in this case report.

  12. Performance of models for estimating absolute risk difference in multicenter trials with binary outcome

    Directory of Open Access Journals (Sweden)

    Claudia Pedroza

    2016-08-01

    Full Text Available Abstract Background Reporting of absolute risk difference (RD is recommended for clinical and epidemiological prospective studies. In analyses of multicenter studies, adjustment for center is necessary when randomization is stratified by center or when there is large variation in patients outcomes across centers. While regression methods are used to estimate RD adjusted for baseline predictors and clustering, no formal evaluation of their performance has been previously conducted. Methods We performed a simulation study to evaluate 6 regression methods fitted under a generalized estimating equation framework: binomial identity, Poisson identity, Normal identity, log binomial, log Poisson, and logistic regression model. We compared the model estimates to unadjusted estimates. We varied the true response function (identity or log, number of subjects per center, true risk difference, control outcome rate, effect of baseline predictor, and intracenter correlation. We compared the models in terms of convergence, absolute bias and coverage of 95 % confidence intervals for RD. Results The 6 models performed very similar to each other for the majority of scenarios. However, the log binomial model did not converge for a large portion of the scenarios including a baseline predictor. In scenarios with outcome rate close to the parameter boundary, the binomial and Poisson identity models had the best performance, but differences from other models were negligible. The unadjusted method introduced little bias to the RD estimates, but its coverage was larger than the nominal value in some scenarios with an identity response. Under the log response, coverage from the unadjusted method was well below the nominal value (<80 % for some scenarios. Conclusions We recommend the use of a binomial or Poisson GEE model with identity link to estimate RD for correlated binary outcome data. If these models fail to run, then either a logistic regression, log Poisson

  13. Subpopulation Treatment Effect Pattern Plot (STEPP) analysis for continuous, binary, and count outcomes.

    Science.gov (United States)

    Yip, Wai-Ki; Bonetti, Marco; Cole, Bernard F; Barcella, William; Wang, Xin Victoria; Lazar, Ann; Gelber, Richard D

    2016-08-01

    For the past few decades, randomized clinical trials have provided evidence for effective treatments by comparing several competing therapies. Their successes have led to numerous new therapies to combat many diseases. However, since their conclusions are based on the entire cohort in the trial, the treatment recommendation is for everyone, and may not be the best option for an individual. Medical research is now focusing more on providing personalized care for patients, which requires investigating how patient characteristics, including novel biomarkers, modify the effect of current treatment modalities. This is known as heterogeneity of treatment effects. A better understanding of the interaction between treatment and patient-specific prognostic factors will enable practitioners to expand the availability of tailored therapies, with the ultimate goal of improving patient outcomes. The Subpopulation Treatment Effect Pattern Plot (STEPP) approach was developed to allow researchers to investigate the heterogeneity of treatment effects on survival outcomes across values of a (continuously measured) covariate, such as a biomarker measurement. Here, we extend the Subpopulation Treatment Effect Pattern Plot approach to continuous, binary, and count outcomes, which can be easily modeled using generalized linear models. With this extension of Subpopulation Treatment Effect Pattern Plot, these additional types of treatment effects within subpopulations defined with respect to a covariate of interest can be estimated, and the statistical significance of any observed heterogeneity of treatment effect can be assessed using permutation tests. The desirable feature that commonly used models are applied to well-defined patient subgroups to estimate treatment effects is retained in this extension. We describe a simulation study to confirm that the proper Type I error rate is maintained when there is no treatment heterogeneity, and a power study to show that the statistics have

  14. Accounting for misclassification bias of binary outcomes due to underscreening: a sensitivity analysis

    Directory of Open Access Journals (Sweden)

    Nanhua Zhang

    2017-12-01

    Full Text Available Abstract Background Diagnostic tests are performed in a subset of the population who are at higher risk, resulting in undiagnosed cases among those who do not receive the test. This poses a challenge for estimating the prevalence of the disease in the study population, and also for studying the risk factors for the disease. Methods We formulate this problem as a missing data problem because the disease status is unknown for those who do not receive the test. We propose a Bayesian selection model which models the joint distribution of the disease outcome and whether testing was received. The sensitivity analysis allows us to assess how the association of the risk factors with the disease outcome as well as the disease prevalence change with the sensitivity parameter. Results We illustrated our model using a retrospective cohort study of children with asthma exacerbation that were evaluated for pneumonia in the emergency department. Our model found that female gender, having fever during ED or at triage, and having severe hypoxia are significantly associated with having radiographic pneumonia. In addition, simulation studies demonstrate that the Bayesian selection model works well even under circumstances when both the disease prevalence and the screening proportion is low. Conclusion The Bayesian selection model is a viable tool to consider for estimating the disease prevalence and in studying risk factors of the disease, when only a subset of the target population receive the test.

  15. What are the appropriate methods for analyzing patient-reported outcomes in randomized trials when data are missing?

    Science.gov (United States)

    Hamel, J F; Sebille, V; Le Neel, T; Kubis, G; Boyer, F C; Hardouin, J B

    2017-12-01

    Subjective health measurements using Patient Reported Outcomes (PRO) are increasingly used in randomized trials, particularly for patient groups comparisons. Two main types of analytical strategies can be used for such data: Classical Test Theory (CTT) and Item Response Theory models (IRT). These two strategies display very similar characteristics when data are complete, but in the common case when data are missing, whether IRT or CTT would be the most appropriate remains unknown and was investigated using simulations. We simulated PRO data such as quality of life data. Missing responses to items were simulated as being completely random, depending on an observable covariate or on an unobserved latent trait. The considered CTT-based methods allowed comparing scores using complete-case analysis, personal mean imputations or multiple-imputations based on a two-way procedure. The IRT-based method was the Wald test on a Rasch model including a group covariate. The IRT-based method and the multiple-imputations-based method for CTT displayed the highest observed power and were the only unbiased method whatever the kind of missing data. Online software and Stata® modules compatibles with the innate mi impute suite are provided for performing such analyses. Traditional procedures (listwise deletion and personal mean imputations) should be avoided, due to inevitable problems of biases and lack of power.

  16. A Bayesian network meta-analysis for binary outcome: how to do it.

    Science.gov (United States)

    Greco, Teresa; Landoni, Giovanni; Biondi-Zoccai, Giuseppe; D'Ascenzo, Fabrizio; Zangrillo, Alberto

    2016-10-01

    This study presents an overview of conceptual and practical issues of a network meta-analysis (NMA), particularly focusing on its application to randomised controlled trials with a binary outcome of interest. We start from general considerations on NMA to specifically appraise how to collect study data, structure the analytical network and specify the requirements for different models and parameter interpretations, with the ultimate goal of providing physicians and clinician-investigators a practical tool to understand pros and cons of NMA. Specifically, we outline the key steps, from the literature search to sensitivity analysis, necessary to perform a valid NMA of binomial data, exploiting Markov Chain Monte Carlo approaches. We also apply this analytical approach to a case study on the beneficial effects of volatile agents compared to total intravenous anaesthetics for surgery to further clarify the statistical details of the models, diagnostics and computations. Finally, datasets and models for the freeware WinBUGS package are presented for the anaesthetic agent example. © The Author(s) 2013.

  17. Partially linear mixed-effects joint models for skewed and missing longitudinal competing risks outcomes.

    Science.gov (United States)

    Lu, Tao; Lu, Minggen; Wang, Min; Zhang, Jun; Dong, Guang-Hui; Xu, Yong

    2017-12-18

    Longitudinal competing risks data frequently arise in clinical studies. Skewness and missingness are commonly observed for these data in practice. However, most joint models do not account for these data features. In this article, we propose partially linear mixed-effects joint models to analyze skew longitudinal competing risks data with missingness. In particular, to account for skewness, we replace the commonly assumed symmetric distributions by asymmetric distribution for model errors. To deal with missingness, we employ an informative missing data model. The joint models that couple the partially linear mixed-effects model for the longitudinal process, the cause-specific proportional hazard model for competing risks process and missing data process are developed. To estimate the parameters in the joint models, we propose a fully Bayesian approach based on the joint likelihood. To illustrate the proposed model and method, we implement them to an AIDS clinical study. Some interesting findings are reported. We also conduct simulation studies to validate the proposed method.

  18. Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review.

    Science.gov (United States)

    Weir, Christopher J; Butcher, Isabella; Assi, Valentina; Lewis, Stephanie C; Murray, Gordon D; Langhorne, Peter; Brady, Marian C

    2018-03-07

    Rigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual participant data. For continuous outcomes, especially those with naturally skewed distributions, summary information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal, we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis. We undertook two systematic literature reviews to identify methodological approaches used to deal with missing mean or variability summary statistics. Five electronic databases were searched, in addition to the Cochrane Colloquium abstract books and the Cochrane Statistics Methods Group mailing list archive. We also conducted cited reference searching and emailed topic experts to identify recent methodological developments. Details recorded included the description of the method, the information required to implement the method, any underlying assumptions and whether the method could be readily applied in standard statistical software. We provided a summary description of the methods identified, illustrating selected methods in example meta-analysis scenarios. For missing standard deviations (SDs), following screening of 503 articles, fifteen methods were identified in addition to those reported in a previous review. These included Bayesian hierarchical modelling at the meta-analysis level; summary statistic level imputation based on observed SD values from other trials in the meta-analysis; a practical approximation based on the range; and algebraic estimation of the SD based on other summary statistics. Following screening of 1124 articles for methods estimating the mean, one approximate Bayesian computation approach and three papers based on alternative summary statistics were identified. Illustrative meta-analyses showed that when replacing a missing SD the approximation using the range minimised loss of precision and generally

  19. Standards should be applied in the prevention and handling of missing data for patient-centered outcomes research: a systematic review and expert consensus.

    Science.gov (United States)

    Li, Tianjing; Hutfless, Susan; Scharfstein, Daniel O; Daniels, Michael J; Hogan, Joseph W; Little, Roderick J A; Roy, Jason A; Law, Andrew H; Dickersin, Kay

    2014-01-01

    To recommend methodological standards in the prevention and handling of missing data for primary patient-centered outcomes research (PCOR). We searched National Library of Medicine Bookshelf and Catalog as well as regulatory agencies' and organizations' Web sites in January 2012 for guidance documents that had formal recommendations regarding missing data. We extracted the characteristics of included guidance documents and recommendations. Using a two-round modified Delphi survey, a multidisciplinary panel proposed mandatory standards on the prevention and handling of missing data for PCOR. We identified 1,790 records and assessed 30 as having relevant recommendations. We proposed 10 standards as mandatory, covering three domains. First, the single best approach is to prospectively prevent missing data occurrence. Second, use of valid statistical methods that properly reflect multiple sources of uncertainty is critical when analyzing missing data. Third, transparent and thorough reporting of missing data allows readers to judge the validity of the findings. We urge researchers to adopt rigorous methodology and promote good science by applying best practices to the prevention and handling of missing data. Developing guidance on the prevention and handling of missing data for observational studies and studies that use existing records is a priority for future research. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Self-declared stock ownership and association with positive trial outcome in randomized controlled trials with binary outcomes published in general medical journals: a cross-sectional study.

    Science.gov (United States)

    Falk Delgado, Alberto; Falk Delgado, Anna

    2017-07-26

    Describe the prevalence and types of conflicts of interest (COI) in published randomized controlled trials (RCTs) in general medical journals with a binary primary outcome and assess the association between conflicts of interest and favorable outcome. Parallel-group RCTs with a binary primary outcome published in three general medical journals during 2013-2015 were identified. COI type, funding source, and outcome were extracted. Binomial logistic regression model was performed to assess association between COI and funding source with outcome. A total of 509 consecutive parallel-group RCTs were included in the study. COI was reported in 74% in mixed funded RCTs and in 99% in for-profit funded RCTs. Stock ownership was reported in none of the non-profit RCTs, in 7% of mixed funded RCTs, and in 50% of for-profit funded RCTs. Mixed-funded RCTs had employees from the funding company in 11% and for-profit RCTs in 76%. Multivariable logistic regression revealed that stock ownership in the funding company among any of the authors was associated with a favorable outcome (odds ratio = 3.53; 95% confidence interval = 1.59-7.86; p < 0.01). COI in for-profit funded RCTs is extensive, because the factors related to COI are not fully independent, a multivariable analysis should be cautiously interpreted. However, after multivariable adjustment only stock ownership from the funding company among authors is associated with a favorable outcome.

  1. Inconsistent definitions for intention-to-treat in relation to missing outcome data: systematic review of the methods literature.

    Science.gov (United States)

    Alshurafa, Mohamad; Briel, Matthias; Akl, Elie A; Haines, Ted; Moayyedi, Paul; Gentles, Stephen J; Rios, Lorena; Tran, Chau; Bhatnagar, Neera; Lamontagne, Francois; Walter, Stephen D; Guyatt, Gordon H

    2012-01-01

    Authors of randomized trial reports seem to hold a variety of views regarding the relationship between missing outcome data (MOD) and intention to treat (ITT). The objectives of this study were to systematically investigate how authors of methodology articles define ITT in the presence of MOD, how they recommend handling MOD under ITT, and to make a proposal for potential improvement in the definition and use of ITT in relation to MOD. We systematically searched MEDLINE in February 2009 for methodological articles written in English that devoted at least one paragraph to ITT and two other paragraphs to either ITT or MOD. We excluded original trial reports, observational studies, and clinical systematic reviews. Working in teams of two, we independently extracted relevant information from each eligible article. Of 1007 titles and abstracts reviewed, 66 articles met eligibility criteria. Five (8%) did not provide a definition of ITT; 25 (38%) mentioned MOD but did not discuss its relationship to ITT; and 36 (55%) discussed the relationship of MOD with ITT. These 36 articles described one or more of three statements: complete follow-up is required for ITT (58%); ITT and MOD are separate issues (17%); and ITT requires a specific strategy for handling MOD (78%); 17 (47%) endorsed more than one relationship. The most frequently mentioned strategies for handling MOD within ITT were: using the last outcome carried forward (50%); sensitivity analysis (50%); and use of available data to impute missing data (46%). We found that there is no consensus on the definition of ITT in relation to MOD. For conceptual clarity, we suggest that both reports of randomized trials and systematic reviews separately consider and describe how they deal with participants with complete data and those with MOD.

  2. Low-molecular-weight cyclin E: the missing link between biology and clinical outcome

    International Nuclear Information System (INIS)

    Akli, Said; Keyomarsi, Khandan

    2004-01-01

    Cyclin E, a key mediator of transition during the G 1 /S cellular division phase, is deregulated in a wide variety of human cancers. Our group recently reported that overexpression and generation of low-molecular-weight (LMW) isoforms of cyclin E were associated with poor clinical outcome among breast cancer patients. However, the link between LMW cyclin E biology in mediating a tumorigenic phenotype and clinical outcome is unknown. To address this gap in knowledge, we assessed the role of LMW isoforms in breast cancer cells; we found that these forms of cyclin E induced genomic instability and resistance to p21, p27, and antiestrogens in breast cancer. These findings suggest that high levels of LMW isoforms of cyclin E not only can predict failure to endocrine therapy but also are true prognostic indicators because of their influence on cell proliferation and genetic instability

  3. Assessment of score- and Rasch-based methods for group comparison of longitudinal patient-reported outcomes with intermittent missing data (informative and non-informative).

    Science.gov (United States)

    de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Sébille, Véronique

    2015-01-01

    The purpose of this study was to identify the most adequate strategy for group comparison of longitudinal patient-reported outcomes in the presence of possibly informative intermittent missing data. Models coming from classical test theory (CTT) and item response theory (IRT) were compared. Two groups of patients' responses to dichotomous items with three times of assessment were simulated. Different cases were considered: presence or absence of a group effect and/or a time effect, a total of 100 or 200 patients, 4 or 7 items and two different values for the correlation coefficient of the latent trait between two consecutive times (0.4 or 0.9). Cases including informative and non-informative intermittent missing data were compared at different rates (15, 30 %). These simulated data were analyzed with CTT using score and mixed model (SM) and with IRT using longitudinal Rasch mixed model (LRM). The type I error, the power and the bias of the group effect estimations were compared between the two methods. This study showed that LRM performs better than SM. When the rate of missing data rose to 30 %, estimations were biased with SM mainly for informative missing data. Otherwise, LRM and SM methods were comparable concerning biases. However, regardless of the rate of intermittent missing data, power of LRM was higher compared to power of SM. In conclusion, LRM should be favored when the rate of missing data is higher than 15 %. For other cases, SM and LRM provide similar results.

  4. A missing link between RON expression and oncological outcomes in resected left-sided pancreatic cancer.

    Science.gov (United States)

    Han, Dai Hoon; Kang, Chang Moo; Lee, Sung Whan; Hwang, Ho Kyoung; Lee, Woo Jung

    2017-10-01

    Alteration and activation of recepteur d'origine nantais (RON) expression is known to be associated with cancer progression and decreased survival in various types of human cancer, including pancreatic cancer. Therefore, in the present study, RON expression levels were determined in resected left-sided pancreatic cancer to evaluate the potential oncological role of RON in the clinical setting of distal pancreatic cancer. From January 2005 to December 2011, a total of 57 patients underwent radical distal pancreatectomy for left-sided pancreatic cancer. Ductal adenocarcinoma was confirmed in all patients. Among these patients, 17 patients who received preoperative neoadjuvant treatment and 7 patients without available paraffin-embedded tissue blocks were excluded from the present study. RON expression in a the pancreatic cancer cell lines ASPC-1, BxPC-3, MiaPaCa-3 and Panc-1, as well as in resected left-sided pancreatic cancer specimens was determined by Western blot analysis. RON and vascular endothelial growth factor (VEGF) overexpression in resected left-sided pancreatic cancer was also evaluated by immunohistochemistry using pre-diluted anti-RON and anti-VEGF antibodies. An association was identified between the oncological outcome and RON overexpression. Increased levels of RON expression were observed in two pancreatic cancer cell lines, AsPC-1 and BxPC-3. RON overexpression was detected in specimens from 15/33 patients (45.5%) using immunohistochemistry. No significant association was identified between RON overexpression and VEGF overexpression (25.5 vs. 87.9%; P=0.667). No significant differences in disease-free survival or disease-specific survival associated with RON overexpression were identified. Although the results of previous studies have suggested that RON is a potential target for the treatment of pancreatic cancer, in the present study no association between RON overexpression and any adverse oncological effect was identified.

  5. Cost: the missing outcome in simulation-based medical education research: a systematic review.

    Science.gov (United States)

    Zendejas, Benjamin; Wang, Amy T; Brydges, Ryan; Hamstra, Stanley J; Cook, David A

    2013-02-01

    The costs involved with technology-enhanced simulation remain unknown. Appraising the value of simulation-based medical education (SBME) requires complete accounting and reporting of cost. We sought to summarize the quantity and quality of studies that contain an economic analysis of SBME for the training of health professions learners. We performed a systematic search of MEDLINE, EMBASE, CINAHL, ERIC, PsychINFO, Scopus, key journals, and previous review bibliographies through May 2011. Articles reporting original research in any language evaluating the cost of simulation, in comparison with nonstimulation instruction or another simulation intervention, for training practicing and student physicians, nurses, and other health professionals were selected. Reviewers working in duplicate evaluated study quality and abstracted information on learners, instructional design, cost elements, and outcomes. From a pool of 10,903 articles we identified 967 comparative studies. Of these, 59 studies (6.1%) reported any cost elements and 15 (1.6%) provided information on cost compared with another instructional approach. We identified 11 cost components reported, most often the cost of the simulator (n = 42 studies; 71%) and training materials (n = 21; 36%). Ten potential cost components were never reported. The median number of cost components reported per study was 2 (range, 1-9). Only 12 studies (20%) reported cost in the Results section; most reported it in the Discussion (n = 34; 58%). Cost reporting in SBME research is infrequent and incomplete. We propose a comprehensive model for accounting and reporting costs in SBME. Copyright © 2013 Mosby, Inc. All rights reserved.

  6. Outcomes of domestic violence screening at an acute London trust: are there missed opportunities for intervention?

    Science.gov (United States)

    Warren-Gash, Charlotte; Bartley, Angela; Bayly, Jude; Dutey-Magni, Peter; Edwards, Sarah; Madge, Sara; Miller, Charlotte; Nicholas, Rachel; Radhakrishnan, Sheila; Sathia, Leena; Swarbrick, Helen; Blaikie, Dee; Rodger, Alison

    2016-01-04

    Domestic violence screening is advocated in some healthcare settings. Evidence that it increases referral to support agencies or improves health outcomes is limited. This study aimed to (1) investigate the proportion of hospital patients reporting domestic violence, (2) describe characteristics and previous hospital attendances of affected patients and (3) assess referrals to an in-house domestic violence advisor from Camden Safety Net. A series of observational studies. Three outpatient clinics at the Royal Free London NHS Foundation Trust. 10,158 patients screened for domestic violence in community gynaecology, genitourinary medicine (GUM) and HIV medicine clinics between 1 October 2013 and 30 June 2014. Also 2253 Camden Safety Net referrals over the same period. (1) Percentage reporting domestic violence by age group gender, ethnicity and clinic. (2) Rates of hospital attendances in the past 3 years for those screening positive and negative. (3) Characteristics, uptake and risk assessment results for hospital in-house domestic violence referrals compared with Camden Safety Net referrals from other sources. Of the 10,158 patients screened, 57.4% were female with a median age of 30 years. Overall, 7.1% reported ever-experiencing domestic violence, ranging from 5.7% in GUM to 29.4% in HIV services. People screening positive for domestic violence had higher rates of previous emergency department attendances (rate ratio (RR) 1.63, 95% CI 1.09 to 2.48), emergency inpatient admissions (RR 2.27, 95% CI 1.37 to 3.84) and day-case admissions (RR 2.03, 95% CI 1.23 to 3.43) than those screening negative. The 77 hospital referrals to the hospital-based domestic violence advisor during the study period were more likely to be taken up and to be classified as high risk than referrals from elsewhere. Selective screening for domestic violence in high-risk hospital clinic populations has the potential to identify affected patients and promote good uptake of referrals for in

  7. Using linked educational attainment data to reduce bias due to missing outcome data in estimates of the association between the duration of breastfeeding and IQ at 15 years.

    Science.gov (United States)

    Cornish, Rosie P; Tilling, Kate; Boyd, Andy; Davies, Amy; Macleod, John

    2015-06-01

    Most epidemiological studies have missing information, leading to reduced power and potential bias. Estimates of exposure-outcome associations will generally be biased if the outcome variable is missing not at random (MNAR). Linkage to administrative data containing a proxy for the missing study outcome allows assessment of whether this outcome is MNAR and the evaluation of bias. We examined this in relation to the association between infant breastfeeding and IQ at 15 years, where a proxy for IQ was available through linkage to school attainment data. Subjects were those who enrolled in the Avon Longitudinal Study of Parents and Children in 1990-91 (n = 13 795), of whom 5023 had IQ measured at age 15. For those with missing IQ, 7030 (79%) had information on educational attainment at age 16 obtained through linkage to the National Pupil Database. The association between duration of breastfeeding and IQ was estimated using a complete case analysis, multiple imputation and inverse probability-of-missingness weighting; these estimates were then compared with those derived from analyses informed by the linkage. IQ at 15 was MNAR-individuals with higher attainment were less likely to have missing IQ data, even after adjusting for socio-demographic factors. All the approaches underestimated the association between breastfeeding and IQ compared with analyses informed by linkage. Linkage to administrative data containing a proxy for the outcome variable allows the MNAR assumption to be tested and more efficient analyses to be performed. Under certain circumstances, this may produce unbiased results. © The Author 2015. Published by Oxford University Press on behalf of the International Epidemiological Association.

  8. Addressing the challenges of obtaining functional outcomes in traumatic brain injury research: missing data patterns, timing of follow-up, and three prognostic models.

    Science.gov (United States)

    Zelnick, Leila R; Morrison, Laurie J; Devlin, Sean M; Bulger, Eileen M; Brasel, Karen J; Sheehan, Kellie; Minei, Joseph P; Kerby, Jeffrey D; Tisherman, Samuel A; Rizoli, Sandro; Karmy-Jones, Riyad; van Heest, Rardi; Newgard, Craig D

    2014-06-01

    Traumatic brain injury (TBI) is common and debilitating. Randomized trials of interventions for TBI ideally assess effectiveness by using long-term functional neurological outcomes, but such outcomes are difficult to obtain and costly. If there is little change between functional status at hospital discharge versus 6 months, then shorter-term outcomes may be adequate for use in future clinical trials. Using data from a previously published multi-center, randomized, placebo-controlled TBI clinical trial, we evaluated patterns of missing outcome data, changes in functional status between hospital discharge and 6 months, and three prognostic models to predict long-term functional outcome from covariates available at hospital discharge (functional measures, demographics, and injury characteristics). The Resuscitation Outcomes Consortium Hypertonic Saline trial enrolled 1282 TBI patients, obtaining the primary outcome of 6-month Glasgow Outcome Score Extended (GOSE) for 85% of patients, but missing the primary outcome for the remaining 15%. Patients with missing outcomes had less-severe injuries, higher neurological function at discharge (GOSE), and shorter hospital stays than patients whose GOSE was obtained. Of 1066 (83%) patients whose GOSE was obtained both at hospital discharge and at 6-months, 71% of patients had the same dichotomized functional status (severe disability/death vs. moderate/no disability) after 6 months as at discharge, 28% had an improved functional status, and 1% had worsened. Performance was excellent (C-statistic between 0.88 and 0.91) for all three prognostic models and calibration adequate for two models (p values, 0.22 and 0.85). Our results suggest that multiple imputation of the standard 6-month GOSE may be reasonable in TBI research when the primary outcome cannot be obtained through other means.

  9. Analysis of binary responses with outcome-specific misclassification probability in genome-wide association studies

    Directory of Open Access Journals (Sweden)

    Rekaya R

    2016-11-01

    Full Text Available Romdhane Rekaya,1–3 Shannon Smith,4 El Hamidi Hay,5 Nourhene Farhat,6 Samuel E Aggrey3,7 1Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, 2Department of Statistics, Franklin College of Arts and Sciences, 3Institute of Bioinformatics, The University of Georgia, Athens, GA, 4Zoetis, Kalamazoo, MI, 5United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, 6Carolinas HealthCare System Blue Ridge, Morganton, NC, 7Department of Poultry Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA Abstract: Errors in the binary status of some response traits are frequent in human, animal, and plant applications. These error rates tend to differ between cases and controls because diagnostic and screening tests have different sensitivity and specificity. This increases the inaccuracies of classifying individuals into correct groups, giving rise to both false-positive and false-negative cases. The analysis of these noisy binary responses due to misclassification will undoubtedly reduce the statistical power of genome-wide association studies (GWAS. A threshold model that accommodates varying diagnostic errors between cases and controls was investigated. A simulation study was carried out where several binary data sets (case–control were generated with varying effects for the most influential single nucleotide polymorphisms (SNPs and different diagnostic error rate for cases and controls. Each simulated data set consisted of 2000 individuals. Ignoring misclassification resulted in biased estimates of true influential SNP effects and inflated estimates for true noninfluential markers. A substantial reduction in bias and increase in accuracy ranging from 12% to 32% was observed when the misclassification procedure was invoked. In fact, the majority of influential SNPs that were not identified using the noisy data were captured using the

  10. Rasch-family models are more valuable than score-based approaches for analysing longitudinal patient-reported outcomes with missing data.

    Science.gov (United States)

    de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Bonnaud-Antignac, Angélique; Dantan, Étienne; Sébille, Véronique

    2016-10-01

    The objective was to compare classical test theory and Rasch-family models derived from item response theory for the analysis of longitudinal patient-reported outcomes data with possibly informative intermittent missing items. A simulation study was performed in order to assess and compare the performance of classical test theory and Rasch model in terms of bias, control of the type I error and power of the test of time effect. The type I error was controlled for classical test theory and Rasch model whether data were complete or some items were missing. Both methods were unbiased and displayed similar power with complete data. When items were missing, Rasch model remained unbiased and displayed higher power than classical test theory. Rasch model performed better than the classical test theory approach regarding the analysis of longitudinal patient-reported outcomes with possibly informative intermittent missing items mainly for power. This study highlights the interest of Rasch-based models in clinical research and epidemiology for the analysis of incomplete patient-reported outcomes data. © The Author(s) 2013.

  11. Causal mediation analysis with a binary outcome and multiple continuous or ordinal mediators: Simulations and application to an alcohol intervention.

    Science.gov (United States)

    Nguyen, Trang Quynh; Webb-Vargas, Yenny; Koning, Ina M; Stuart, Elizabeth A

    We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: 1) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, 2) predict potential outcome probabilities, and 3) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance/covariance. We evaluate the estimation of risk-difference- and risk-ratio-based effects (RDs, RRs) using the ML, WLSMV and Bayes estimators in Mplus. Across most variations in path-coefficient and mediator-residual-correlation signs and strengths, and confounding situations investigated, the method performs well with all estimators, but favors ML/WLSMV for RDs with continuous mediators, and Bayes for RRs with ordinal mediators. Bayes outperforms WLSMV/ML regardless of mediator type when estimating RRs with small potential outcome probabilities and in two other special cases. An adolescent alcohol prevention study is used for illustration.

  12. Accounting for interactions and complex inter-subject dependency in estimating treatment effect in cluster-randomized trials with missing outcomes.

    Science.gov (United States)

    Prague, Melanie; Wang, Rui; Stephens, Alisa; Tchetgen Tchetgen, Eric; DeGruttola, Victor

    2016-12-01

    Semi-parametric methods are often used for the estimation of intervention effects on correlated outcomes in cluster-randomized trials (CRTs). When outcomes are missing at random (MAR), Inverse Probability Weighted (IPW) methods incorporating baseline covariates can be used to deal with informative missingness. Also, augmented generalized estimating equations (AUG) correct for imbalance in baseline covariates but need to be extended for MAR outcomes. However, in the presence of interactions between treatment and baseline covariates, neither method alone produces consistent estimates for the marginal treatment effect if the model for interaction is not correctly specified. We propose an AUG-IPW estimator that weights by the inverse of the probability of being a complete case and allows different outcome models in each intervention arm. This estimator is doubly robust (DR); it gives correct estimates whether the missing data process or the outcome model is correctly specified. We consider the problem of covariate interference which arises when the outcome of an individual may depend on covariates of other individuals. When interfering covariates are not modeled, the DR property prevents bias as long as covariate interference is not present simultaneously for the outcome and the missingness. An R package is developed implementing the proposed method. An extensive simulation study and an application to a CRT of HIV risk reduction-intervention in South Africa illustrate the method. © 2016, The International Biometric Society.

  13. Assessment and implication of prognostic imbalance in randomized controlled trials with a binary outcome--a simulation study.

    Directory of Open Access Journals (Sweden)

    Rong Chu

    Full Text Available Chance imbalance in baseline prognosis of a randomized controlled trial can lead to over or underestimation of treatment effects, particularly in trials with small sample sizes. Our study aimed to (1 evaluate the probability of imbalance in a binary prognostic factor (PF between two treatment arms, (2 investigate the impact of prognostic imbalance on the estimation of a treatment effect, and (3 examine the effect of sample size (n in relation to the first two objectives.We simulated data from parallel-group trials evaluating a binary outcome by varying the risk of the outcome, effect of the treatment, power and prevalence of the PF, and n. Logistic regression models with and without adjustment for the PF were compared in terms of bias, standard error, coverage of confidence interval and statistical power.For a PF with a prevalence of 0.5, the probability of a difference in the frequency of the PF≥5% reaches 0.42 with 125/arm. Ignoring a strong PF (relative risk = 5 leads to underestimating the strength of a moderate treatment effect, and the underestimate is independent of n when n is >50/arm. Adjusting for such PF increases statistical power. If the PF is weak (RR = 2, adjustment makes little difference in statistical inference. Conditional on a 5% imbalance of a powerful PF, adjustment reduces the likelihood of large bias. If an absolute measure of imbalance ≥5% is deemed important, including 1000 patients/arm provides sufficient protection against such an imbalance. Two thousand patients/arm may provide an adequate control against large random deviations in treatment effect estimation in the presence of a powerful PF.The probability of prognostic imbalance in small trials can be substantial. Covariate adjustment improves estimation accuracy and statistical power, and hence should be performed when strong PFs are observed.

  14. Assessment and Implication of Prognostic Imbalance in Randomized Controlled Trials with a Binary Outcome – A Simulation Study

    Science.gov (United States)

    Chu, Rong; Walter, Stephen D.; Guyatt, Gordon; Devereaux, P. J.; Walsh, Michael; Thorlund, Kristian; Thabane, Lehana

    2012-01-01

    Background Chance imbalance in baseline prognosis of a randomized controlled trial can lead to over or underestimation of treatment effects, particularly in trials with small sample sizes. Our study aimed to (1) evaluate the probability of imbalance in a binary prognostic factor (PF) between two treatment arms, (2) investigate the impact of prognostic imbalance on the estimation of a treatment effect, and (3) examine the effect of sample size (n) in relation to the first two objectives. Methods We simulated data from parallel-group trials evaluating a binary outcome by varying the risk of the outcome, effect of the treatment, power and prevalence of the PF, and n. Logistic regression models with and without adjustment for the PF were compared in terms of bias, standard error, coverage of confidence interval and statistical power. Results For a PF with a prevalence of 0.5, the probability of a difference in the frequency of the PF≥5% reaches 0.42 with 125/arm. Ignoring a strong PF (relative risk = 5) leads to underestimating the strength of a moderate treatment effect, and the underestimate is independent of n when n is >50/arm. Adjusting for such PF increases statistical power. If the PF is weak (RR = 2), adjustment makes little difference in statistical inference. Conditional on a 5% imbalance of a powerful PF, adjustment reduces the likelihood of large bias. If an absolute measure of imbalance ≥5% is deemed important, including 1000 patients/arm provides sufficient protection against such an imbalance. Two thousand patients/arm may provide an adequate control against large random deviations in treatment effect estimation in the presence of a powerful PF. Conclusions The probability of prognostic imbalance in small trials can be substantial. Covariate adjustment improves estimation accuracy and statistical power, and hence should be performed when strong PFs are observed. PMID:22629322

  15. Imputation by the mean score should be avoided when validating a Patient Reported Outcomes questionnaire by a Rasch model in presence of informative missing data

    LENUS (Irish Health Repository)

    Hardouin, Jean-Benoit

    2011-07-14

    Abstract Background Nowadays, more and more clinical scales consisting in responses given by the patients to some items (Patient Reported Outcomes - PRO), are validated with models based on Item Response Theory, and more specifically, with a Rasch model. In the validation sample, presence of missing data is frequent. The aim of this paper is to compare sixteen methods for handling the missing data (mainly based on simple imputation) in the context of psychometric validation of PRO by a Rasch model. The main indexes used for validation by a Rasch model are compared. Methods A simulation study was performed allowing to consider several cases, notably the possibility for the missing values to be informative or not and the rate of missing data. Results Several imputations methods produce bias on psychometrical indexes (generally, the imputation methods artificially improve the psychometric qualities of the scale). In particular, this is the case with the method based on the Personal Mean Score (PMS) which is the most commonly used imputation method in practice. Conclusions Several imputation methods should be avoided, in particular PMS imputation. From a general point of view, it is important to use an imputation method that considers both the ability of the patient (measured for example by his\\/her score), and the difficulty of the item (measured for example by its rate of favourable responses). Another recommendation is to always consider the addition of a random process in the imputation method, because such a process allows reducing the bias. Last, the analysis realized without imputation of the missing data (available case analyses) is an interesting alternative to the simple imputation in this context.

  16. Joint modeling of correlated binary outcomes: The case of contraceptive use and HIV knowledge in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Di Fang

    Full Text Available Recent advances in statistical methods enable the study of correlation among outcomes through joint modeling, thereby addressing spillover effects. By joint modeling, we refer to simultaneously analyzing two or more different response variables emanating from the same individual. Using the 2011 Bangladesh Demographic and Health Survey, we jointly address spillover effects between contraceptive use (CUC and knowledge of HIV and other sexually transmitted diseases. Jointly modeling these two outcomes is appropriate because certain types of contraceptive use contribute to the prevention of HIV and STDs and the knowledge and awareness of HIV and STDs typically lead to protection during sexual intercourse. In particular, we compared the differences as they pertained to the interpretive advantage of modeling the spillover effects of joint modeling HIV and CUC as opposed to addressing them separately. We also identified risk factors that determine contraceptive use and knowledge of HIV and STDs among women in Bangladesh. We found that by jointly modeling the correlation between HIV knowledge and contraceptive use, the importance of education decreased. The HIV prevention program had a spillover effect on CUC: what seemed to be impacted by education can be partially contributed to one's exposure to HIV knowledge. The joint model revealed a less significant impact of covariates as opposed to both separate models and standard models. Additionally, we found a spillover effect that would have otherwise been undiscovered if we did not jointly model. These findings further suggested that the simultaneous impact of correlated outcomes can be adequately addressed for the commonality between different responses and deflate, which is otherwise overestimated when examined separately.

  17. Bayesian dose selection design for a binary outcome using restricted response adaptive randomization.

    Science.gov (United States)

    Meinzer, Caitlyn; Martin, Renee; Suarez, Jose I

    2017-09-08

    In phase II trials, the most efficacious dose is usually not known. Moreover, given limited resources, it is difficult to robustly identify a dose while also testing for a signal of efficacy that would support a phase III trial. Recent designs have sought to be more efficient by exploring multiple doses through the use of adaptive strategies. However, the added flexibility may potentially increase the risk of making incorrect assumptions and reduce the total amount of information available across the dose range as a function of imbalanced sample size. To balance these challenges, a novel placebo-controlled design is presented in which a restricted Bayesian response adaptive randomization (RAR) is used to allocate a majority of subjects to the optimal dose of active drug, defined as the dose with the lowest probability of poor outcome. However, the allocation between subjects who receive active drug or placebo is held constant to retain the maximum possible power for a hypothesis test of overall efficacy comparing the optimal dose to placebo. The design properties and optimization of the design are presented in the context of a phase II trial for subarachnoid hemorrhage. For a fixed total sample size, a trade-off exists between the ability to select the optimal dose and the probability of rejecting the null hypothesis. This relationship is modified by the allocation ratio between active and control subjects, the choice of RAR algorithm, and the number of subjects allocated to an initial fixed allocation period. While a responsive RAR algorithm improves the ability to select the correct dose, there is an increased risk of assigning more subjects to a worse arm as a function of ephemeral trends in the data. A subarachnoid treatment trial is used to illustrate how this design can be customized for specific objectives and available data. Bayesian adaptive designs are a flexible approach to addressing multiple questions surrounding the optimal dose for treatment efficacy

  18. Public Response to a Near-Miss Nuclear Accident Scenario Varying in Causal Attributions and Outcome Uncertainty.

    Science.gov (United States)

    Cui, Jinshu; Rosoff, Heather; John, Richard S

    2018-05-01

    Many studies have investigated public reactions to nuclear accidents. However, few studies focused on more common events when a serious accident could have happened but did not. This study evaluated public response (emotional, cognitive, and behavioral) over three phases of a near-miss nuclear accident. Simulating a loss-of-coolant accident (LOCA) scenario, we manipulated (1) attribution for the initial cause of the incident (software failure vs. cyber terrorist attack vs. earthquake), (2) attribution for halting the incident (fail-safe system design vs. an intervention by an individual expert vs. a chance coincidence), and (3) level of uncertainty (certain vs. uncertain) about risk of a future radiation leak after the LOCA is halted. A total of 773 respondents were sampled using a 3 × 3 × 2 between-subjects design. Results from both MANCOVA and structural equation modeling (SEM) indicate that respondents experienced more negative affect, perceived more risk, and expressed more avoidance behavioral intention when the near-miss event was initiated by an external attributed source (e.g., earthquake) compared to an internally attributed source (e.g., software failure). Similarly, respondents also indicated greater negative affect, perceived risk, and avoidance behavioral intentions when the future impact of the near-miss incident on people and the environment remained uncertain. Results from SEM analyses also suggested that negative affect predicted risk perception, and both predicted avoidance behavior. Affect, risk perception, and avoidance behavior demonstrated high stability (i.e., reliability) from one phase to the next. © 2017 Society for Risk Analysis.

  19. A nonparametric multiple imputation approach for missing categorical data

    Directory of Open Access Journals (Sweden)

    Muhan Zhou

    2017-06-01

    more than two levels for assessing the distribution of the outcome. In terms of the choices for the working models, we suggest a multinomial logistic regression for predicting the missing outcome and a binary logistic regression for predicting the missingness probability.

  20. The significance of Sampling Design on Inference: An Analysis of Binary Outcome Model of Children’s Schooling Using Indonesian Large Multi-stage Sampling Data

    OpenAIRE

    Ekki Syamsulhakim

    2008-01-01

    This paper aims to exercise a rather recent trend in applied microeconometrics, namely the effect of sampling design on statistical inference, especially on binary outcome model. Many theoretical research in econometrics have shown the inappropriateness of applying i.i.dassumed statistical analysis on non-i.i.d data. These research have provided proofs showing that applying the iid-assumed analysis on a non-iid observations would result in an inflated standard errors which could make the esti...

  1. Missing School Matters

    Science.gov (United States)

    Balfanz, Robert

    2016-01-01

    Results of a survey conducted by the Office for Civil Rights show that 6 million public school students (13%) are not attending school regularly. Chronic absenteeism--defined as missing more than 10% of school for any reason--has been negatively linked to many key academic outcomes. Evidence shows that students who exit chronic absentee status can…

  2. Interacting binaries

    International Nuclear Information System (INIS)

    Eggleton, P.P.; Pringle, J.E.

    1985-01-01

    This volume contains 15 review articles in the field of binary stars. The subjects reviewed span considerably, from the shortest period of interacting binaries to the longest, symbiotic stars. Also included are articles on Algols, X-ray binaries and Wolf-Rayet stars (single and binary). Contents: Preface. List of Participants. Activity of Contact Binary Systems. Wolf-Rayet Stars and Binarity. Symbiotic Stars. Massive X-ray Binaries. Stars that go Hump in the Night: The SU UMa Stars. Interacting Binaries - Summing Up

  3. Comparison of robustness to outliers between robust poisson models and log-binomial models when estimating relative risks for common binary outcomes: a simulation study.

    Science.gov (United States)

    Chen, Wansu; Shi, Jiaxiao; Qian, Lei; Azen, Stanley P

    2014-06-26

    To estimate relative risks or risk ratios for common binary outcomes, the most popular model-based methods are the robust (also known as modified) Poisson and the log-binomial regression. Of the two methods, it is believed that the log-binomial regression yields more efficient estimators because it is maximum likelihood based, while the robust Poisson model may be less affected by outliers. Evidence to support the robustness of robust Poisson models in comparison with log-binomial models is very limited. In this study a simulation was conducted to evaluate the performance of the two methods in several scenarios where outliers existed. The findings indicate that for data coming from a population where the relationship between the outcome and the covariate was in a simple form (e.g. log-linear), the two models yielded comparable biases and mean square errors. However, if the true relationship contained a higher order term, the robust Poisson models consistently outperformed the log-binomial models even when the level of contamination is low. The robust Poisson models are more robust (or less sensitive) to outliers compared to the log-binomial models when estimating relative risks or risk ratios for common binary outcomes. Users should be aware of the limitations when choosing appropriate models to estimate relative risks or risk ratios.

  4. Postoperative outcome after oesophagectomy for cancer: Nutritional status is the missing ring in the current prognostic scores.

    Science.gov (United States)

    Filip, B; Scarpa, M; Cavallin, F; Cagol, M; Alfieri, R; Saadeh, L; Ancona, E; Castoro, C

    2015-06-01

    Several prognostic scores were designed in order to estimate the risk of postoperative adverse events. None of them includes a component directly associated to the nutritional status. The aims of the study were the evaluation of performance of risk-adjusted models for early outcomes after oesophagectomy and to develop a score for severe complication prediction with special consideration regarding nutritional status. A comparison of POSSUM and Charlson score and their derivates, ASA, Lagarde score and nutritional index (PNI) was performed on 167 patients undergoing oesophagectomy for cancer. A logistic regression model was also estimated to obtain a new prognostic score for severe morbidity prediction. Overall morbidity was 35.3% (59 cases), severe complications (grade III-V of Clavien-Dindo classification) occurred in 20 cases. Discrimination was poor for all the scores. Multivariable analysis identified pulse, connective tissue disease, PNI and potassium as independent predictors of severe morbidity. This model showed good discrimination and calibration. Internal validation using standard bootstrapping techniques confirmed the good performance. Nutrition could be an independent risk factor for major complications and a nutritional status coefficient could be included in current prognostic scores to improve risk estimation of major postoperative complications after oesophagectomy for cancer. Copyright © 2015. Published by Elsevier Ltd.

  5. A comparison of confidence interval methods for the intraclass correlation coefficient in community-based cluster randomization trials with a binary outcome.

    Science.gov (United States)

    Braschel, Melissa C; Svec, Ivana; Darlington, Gerarda A; Donner, Allan

    2016-04-01

    Many investigators rely on previously published point estimates of the intraclass correlation coefficient rather than on their associated confidence intervals to determine the required size of a newly planned cluster randomized trial. Although confidence interval methods for the intraclass correlation coefficient that can be applied to community-based trials have been developed for a continuous outcome variable, fewer methods exist for a binary outcome variable. The aim of this study is to evaluate confidence interval methods for the intraclass correlation coefficient applied to binary outcomes in community intervention trials enrolling a small number of large clusters. Existing methods for confidence interval construction are examined and compared to a new ad hoc approach based on dividing clusters into a large number of smaller sub-clusters and subsequently applying existing methods to the resulting data. Monte Carlo simulation is used to assess the width and coverage of confidence intervals for the intraclass correlation coefficient based on Smith's large sample approximation of the standard error of the one-way analysis of variance estimator, an inverted modified Wald test for the Fleiss-Cuzick estimator, and intervals constructed using a bootstrap-t applied to a variance-stabilizing transformation of the intraclass correlation coefficient estimate. In addition, a new approach is applied in which clusters are randomly divided into a large number of smaller sub-clusters with the same methods applied to these data (with the exception of the bootstrap-t interval, which assumes large cluster sizes). These methods are also applied to a cluster randomized trial on adolescent tobacco use for illustration. When applied to a binary outcome variable in a small number of large clusters, existing confidence interval methods for the intraclass correlation coefficient provide poor coverage. However, confidence intervals constructed using the new approach combined with Smith

  6. Predicting treatment effect from surrogate endpoints and historical trials: an extrapolation involving probabilities of a binary outcome or survival to a specific time.

    Science.gov (United States)

    Baker, Stuart G; Sargent, Daniel J; Buyse, Marc; Burzykowski, Tomasz

    2012-03-01

    Using multiple historical trials with surrogate and true endpoints, we consider various models to predict the effect of treatment on a true endpoint in a target trial in which only a surrogate endpoint is observed. This predicted result is computed using (1) a prediction model (mixture, linear, or principal stratification) estimated from historical trials and the surrogate endpoint of the target trial and (2) a random extrapolation error estimated from successively leaving out each trial among the historical trials. The method applies to either binary outcomes or survival to a particular time that is computed from censored survival data. We compute a 95% confidence interval for the predicted result and validate its coverage using simulation. To summarize the additional uncertainty from using a predicted instead of true result for the estimated treatment effect, we compute its multiplier of standard error. Software is available for download. © 2011, The International Biometric Society No claim to original US government works.

  7. Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wan-Yu [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Kuo, Sung-Hsin [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Chen, Yu-Hsuan; Lu, Szu-Huai; Tsai, Chiao-Ling [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chia-Hsien Cheng, Jason [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan (China); Hong, Ruey-Long [Division of Medical Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Ya-Fang [Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan (China); Hsu, Chuan-Jen; Lin, Kai-Nan; Ko, Jenq-Yuh; Lou, Pei-Jen; Wang, Cheng-Ping [Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan (China); Chong, Fok-Ching [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Chun-Wei, E-mail: cwwang@ntuh.gov.tw [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)

    2012-03-15

    Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6-33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

  8. Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

    International Nuclear Information System (INIS)

    Chen, Wan-Yu; Kuo, Sung-Hsin; Chen, Yu-Hsuan; Lu, Szu-Huai; Tsai, Chiao-Ling; Chia-Hsien Cheng, Jason; Hong, Ruey-Long; Chen, Ya-Fang; Hsu, Chuan-Jen; Lin, Kai-Nan; Ko, Jenq-Yuh; Lou, Pei-Jen; Wang, Cheng-Ping; Chong, Fok-Ching; Wang, Chun-Wei

    2012-01-01

    Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6–33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

  9. Interacting binaries

    CERN Document Server

    Shore, S N; van den Heuvel, EPJ

    1994-01-01

    This volume contains lecture notes presented at the 22nd Advanced Course of the Swiss Society for Astrophysics and Astronomy. The contributors deal with symbiotic stars, cataclysmic variables, massive binaries and X-ray binaries, in an attempt to provide a better understanding of stellar evolution.

  10. Missing money and missing markets: Reliability, capacity auctions and interconnectors

    International Nuclear Information System (INIS)

    Newbery, David

    2016-01-01

    In the energy trilemma of reliability, sustainability and affordability, politicians treat reliability as over-riding. The EU assumes the energy-only Target Electricity Model will deliver reliability but the UK argues that a capacity remuneration mechanism is needed. This paper argues that capacity auctions tend to over-procure capacity, exacerbating the missing money problem they were designed to address. The bias is further exacerbated by failing to address some of the missing market problems also neglected in the debate. It examines the case for, criticisms of, and outcome of the first GB capacity auction and problems of trading between different capacity markets. - Highlights: •Energy-only markets can work if they avoid missing money and missing market problems. •Policy makers over-estimate the cost of so-called “loss of load events”. •Policy makers tend to over-procure capacity, exacerbating the missing money problem. •Rectifying missing market problems simplifies trade between different capacity markets. •Addressing missing market problems makes under-procurement cheaper than over-procurement.

  11. Generalized linear mixed model for binary outcomes when covariates are subject to measurement errors and detection limits.

    Science.gov (United States)

    Xie, Xianhong; Xue, Xiaonan; Strickler, Howard D

    2018-01-15

    Longitudinal measurement of biomarkers is important in determining risk factors for binary endpoints such as infection or disease. However, biomarkers are subject to measurement error, and some are also subject to left-censoring due to a lower limit of detection. Statistical methods to address these issues are few. We herein propose a generalized linear mixed model and estimate the model parameters using the Monte Carlo Newton-Raphson (MCNR) method. Inferences regarding the parameters are made by applying Louis's method and the delta method. Simulation studies were conducted to compare the proposed MCNR method with existing methods including the maximum likelihood (ML) method and the ad hoc approach of replacing the left-censored values with half of the detection limit (HDL). The results showed that the performance of the MCNR method is superior to ML and HDL with respect to the empirical standard error, as well as the coverage probability for the 95% confidence interval. The HDL method uses an incorrect imputation method, and the computation is constrained by the number of quadrature points; while the ML method also suffers from the constrain for the number of quadrature points, the MCNR method does not have this limitation and approximates the likelihood function better than the other methods. The improvement of the MCNR method is further illustrated with real-world data from a longitudinal study of local cervicovaginal HIV viral load and its effects on oncogenic HPV detection in HIV-positive women. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Trojan Binaries

    Science.gov (United States)

    Noll, K. S.

    2017-12-01

    The Jupiter Trojans, in the context of giant planet migration models, can be thought of as an extension of the small body populations found beyond Neptune in the Kuiper Belt. Binaries are a distinctive feature of small body populations in the Kuiper Belt with an especially high fraction apparent among the brightest Cold Classicals. The binary fraction, relative sizes, and separations in the dynamically excited populations (Scattered, Resonant) reflects processes that may have eroded a more abundant initial population. This trend continues in the Centaurs and Trojans where few binaries have been found. We review new evidence including a third resolved Trojan binary and lightcurve studies to understand how the Trojans are related to the small body populations that originated in the outer protoplanetary disk.

  13. Statistical analysis with missing exposure data measured by proxy respondents: a misclassification problem within a missing-data problem.

    Science.gov (United States)

    Shardell, Michelle; Hicks, Gregory E

    2014-11-10

    In studies of older adults, researchers often recruit proxy respondents, such as relatives or caregivers, when study participants cannot provide self-reports (e.g., because of illness). Proxies are usually only sought to report on behalf of participants with missing self-reports; thus, either a participant self-report or proxy report, but not both, is available for each participant. Furthermore, the missing-data mechanism for participant self-reports is not identifiable and may be nonignorable. When exposures are binary and participant self-reports are conceptualized as the gold standard, substituting error-prone proxy reports for missing participant self-reports may produce biased estimates of outcome means. Researchers can handle this data structure by treating the problem as one of misclassification within the stratum of participants with missing self-reports. Most methods for addressing exposure misclassification require validation data, replicate data, or an assumption of nondifferential misclassification; other methods may result in an exposure misclassification model that is incompatible with the analysis model. We propose a model that makes none of the aforementioned requirements and still preserves model compatibility. Two user-specified tuning parameters encode the exposure misclassification model. Two proposed approaches estimate outcome means standardized for (potentially) high-dimensional covariates using multiple imputation followed by propensity score methods. The first method is parametric and uses maximum likelihood to estimate the exposure misclassification model (i.e., the imputation model) and the propensity score model (i.e., the analysis model); the second method is nonparametric and uses boosted classification and regression trees to estimate both models. We apply both methods to a study of elderly hip fracture patients. Copyright © 2014 John Wiley & Sons, Ltd.

  14. ON THE APPARENT LACK OF Be X-RAY BINARIES WITH BLACK HOLES

    International Nuclear Information System (INIS)

    Belczynski, Krzysztof; Ziolkowski, Janusz

    2009-01-01

    In our Galaxy there are 64 Be X-ray binaries known to date. Out of these, 42 host a neutron star (NS), and for the remainder the nature of the companion is unknown. None, so far, are known to host a black hole (BH). There seems to be no apparent mechanism that would prevent formation or detection of Be stars with BHs. This disparity is referred to as a missing Be-BH X-ray binary problem. We point out that current evolutionary scenarios that lead to the formation of Be X-ray binaries predict that the ratio of binaries with NSs to the ones with BHs is rather high, F NStoBH ∼ 10-50, with the more likely formation models providing the values at the high end. The ratio is a natural outcome of (1) the stellar initial mass function that produces more NSs than BHs and (2) common envelope evolution (i.e., a major mechanism involved in the formation of interacting binaries) that naturally selects progenitors of Be X-ray binaries with NSs (binaries with comparable mass components have more likely survival probabilities) over ones with BHs (which are much more likely to be common envelope mergers). A comparison of this ratio (i.e., F NStoBH ∼ 30) with the number of confirmed Be-NS X-ray binaries (42) indicates that the expected number of Be-BH X-ray binaries is of the order of only ∼0-2. This is entirely consistent with the observed Galactic sample.

  15. A population-based surveillance study on severe acute maternal morbidity (near-miss and adverse perinatal outcomes in Campinas, Brazil: The Vigimoma Project

    Directory of Open Access Journals (Sweden)

    Cecatti José

    2011-01-01

    Full Text Available Abstract Background Auditing of sentinel health events based on best-practice protocols has been recommended. This study describes a population-based investigation on adverse perinatal events including severe acute maternal morbidity (near-miss, maternal and perinatal mortality, as a health intervention to help improve the surveillance system. Methods From October to December 2005, all cases of maternal death (MD, near-miss (NM, fetal deaths (FD, and early neonatal deaths (END, occurring in Campinas, Brazil, were audited by maternal mortality committees. Results A total of 4,491 liveborn infants (LB and 159 adverse perinatal events (35.4/1000 LB were revised, consisting of 4 MD (89/100.000 LB and 95 NM (21.1/1000 LB, 23.7 NM for each MD. In addition, 32 FD (7.1/1000 LB and 28 END (6.2/1000 LB occurred. The maternal death/near miss rate was 23.7:1. Some delay in care was recognized for 34%, and hypertensive complications comprised 57.8% of the NM events, followed by postpartum hemorrhage. Conclusion Auditing near miss cases expanded the understanding of the spectrum from maternal morbidity to mortality and the importance of promoting adhesion to clinical protocols among maternal mortality committee members. Hypertensive disorders and postpartum hemorrhage were identified as priority topics for health providers training, and organization of care.

  16. Mendelian randomization analysis of a time-varying exposure for binary disease outcomes using functional data analysis methods.

    Science.gov (United States)

    Cao, Ying; Rajan, Suja S; Wei, Peng

    2016-12-01

    A Mendelian randomization (MR) analysis is performed to analyze the causal effect of an exposure variable on a disease outcome in observational studies, by using genetic variants that affect the disease outcome only through the exposure variable. This method has recently gained popularity among epidemiologists given the success of genetic association studies. Many exposure variables of interest in epidemiological studies are time varying, for example, body mass index (BMI). Although longitudinal data have been collected in many cohort studies, current MR studies only use one measurement of a time-varying exposure variable, which cannot adequately capture the long-term time-varying information. We propose using the functional principal component analysis method to recover the underlying individual trajectory of the time-varying exposure from the sparsely and irregularly observed longitudinal data, and then conduct MR analysis using the recovered curves. We further propose two MR analysis methods. The first assumes a cumulative effect of the time-varying exposure variable on the disease risk, while the second assumes a time-varying genetic effect and employs functional regression models. We focus on statistical testing for a causal effect. Our simulation studies mimicking the real data show that the proposed functional data analysis based methods incorporating longitudinal data have substantial power gains compared to standard MR analysis using only one measurement. We used the Framingham Heart Study data to demonstrate the promising performance of the new methods as well as inconsistent results produced by the standard MR analysis that relies on a single measurement of the exposure at some arbitrary time point. © 2016 WILEY PERIODICALS, INC.

  17. Introduction to methodology of dose-response meta-analysis for binary outcome: With application on software.

    Science.gov (United States)

    Zhang, Chao; Jia, Pengli; Yu, Liu; Xu, Chang

    2018-05-01

    Dose-response meta-analysis (DRMA) is widely applied to investigate the dose-specific relationship between independent and dependent variables. Such methods have been in use for over 30 years and are increasingly employed in healthcare and clinical decision-making. In this article, we give an overview of the methodology used in DRMA. We summarize the commonly used regression model and the pooled method in DRMA. We also use an example to illustrate how to employ a DRMA by these methods. Five regression models, linear regression, piecewise regression, natural polynomial regression, fractional polynomial regression, and restricted cubic spline regression, were illustrated in this article to fit the dose-response relationship. And two types of pooling approaches, that is, one-stage approach and two-stage approach are illustrated to pool the dose-response relationship across studies. The example showed similar results among these models. Several dose-response meta-analysis methods can be used for investigating the relationship between exposure level and the risk of an outcome. However the methodology of DRMA still needs to be improved. © 2018 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

  18. The Effect of Latent Binary Variables on the Uncertainty of the Prediction of a Dichotomous Outcome Using Logistic Regression Based Propensity Score Matching.

    Science.gov (United States)

    Szekér, Szabolcs; Vathy-Fogarassy, Ágnes

    2018-01-01

    Logistic regression based propensity score matching is a widely used method in case-control studies to select the individuals of the control group. This method creates a suitable control group if all factors affecting the output variable are known. However, if relevant latent variables exist as well, which are not taken into account during the calculations, the quality of the control group is uncertain. In this paper, we present a statistics-based research in which we try to determine the relationship between the accuracy of the logistic regression model and the uncertainty of the dependent variable of the control group defined by propensity score matching. Our analyses show that there is a linear correlation between the fit of the logistic regression model and the uncertainty of the output variable. In certain cases, a latent binary explanatory variable can result in a relative error of up to 70% in the prediction of the outcome variable. The observed phenomenon calls the attention of analysts to an important point, which must be taken into account when deducting conclusions.

  19. Sample size adjustments for varying cluster sizes in cluster randomized trials with binary outcomes analyzed with second-order PQL mixed logistic regression.

    Science.gov (United States)

    Candel, Math J J M; Van Breukelen, Gerard J P

    2010-06-30

    Adjustments of sample size formulas are given for varying cluster sizes in cluster randomized trials with a binary outcome when testing the treatment effect with mixed effects logistic regression using second-order penalized quasi-likelihood estimation (PQL). Starting from first-order marginal quasi-likelihood (MQL) estimation of the treatment effect, the asymptotic relative efficiency of unequal versus equal cluster sizes is derived. A Monte Carlo simulation study shows this asymptotic relative efficiency to be rather accurate for realistic sample sizes, when employing second-order PQL. An approximate, simpler formula is presented to estimate the efficiency loss due to varying cluster sizes when planning a trial. In many cases sampling 14 per cent more clusters is sufficient to repair the efficiency loss due to varying cluster sizes. Since current closed-form formulas for sample size calculation are based on first-order MQL, planning a trial also requires a conversion factor to obtain the variance of the second-order PQL estimator. In a second Monte Carlo study, this conversion factor turned out to be 1.25 at most. (c) 2010 John Wiley & Sons, Ltd.

  20. A scan statistic for binary outcome based on hypergeometric probability model, with an application to detecting spatial clusters of Japanese encephalitis.

    Science.gov (United States)

    Zhao, Xing; Zhou, Xiao-Hua; Feng, Zijian; Guo, Pengfei; He, Hongyan; Zhang, Tao; Duan, Lei; Li, Xiaosong

    2013-01-01

    As a useful tool for geographical cluster detection of events, the spatial scan statistic is widely applied in many fields and plays an increasingly important role. The classic version of the spatial scan statistic for the binary outcome is developed by Kulldorff, based on the Bernoulli or the Poisson probability model. In this paper, we apply the Hypergeometric probability model to construct the likelihood function under the null hypothesis. Compared with existing methods, the likelihood function under the null hypothesis is an alternative and indirect method to identify the potential cluster, and the test statistic is the extreme value of the likelihood function. Similar with Kulldorff's methods, we adopt Monte Carlo test for the test of significance. Both methods are applied for detecting spatial clusters of Japanese encephalitis in Sichuan province, China, in 2009, and the detected clusters are identical. Through a simulation to independent benchmark data, it is indicated that the test statistic based on the Hypergeometric model outweighs Kulldorff's statistics for clusters of high population density or large size; otherwise Kulldorff's statistics are superior.

  1. Binary effectivity rules

    DEFF Research Database (Denmark)

    Keiding, Hans; Peleg, Bezalel

    2006-01-01

    is binary if it is rationalized by an acyclic binary relation. The foregoing result motivates our definition of a binary effectivity rule as the effectivity rule of some binary SCR. A binary SCR is regular if it satisfies unanimity, monotonicity, and independence of infeasible alternatives. A binary...

  2. How large are the consequences of covariate imbalance in cluster randomized trials: a simulation study with a continuous outcome and a binary covariate at the cluster level.

    Science.gov (United States)

    Moerbeek, Mirjam; van Schie, Sander

    2016-07-11

    The number of clusters in a cluster randomized trial is often low. It is therefore likely random assignment of clusters to treatment conditions results in covariate imbalance. There are no studies that quantify the consequences of covariate imbalance in cluster randomized trials on parameter and standard error bias and on power to detect treatment effects. The consequences of covariance imbalance in unadjusted and adjusted linear mixed models are investigated by means of a simulation study. The factors in this study are the degree of imbalance, the covariate effect size, the cluster size and the intraclass correlation coefficient. The covariate is binary and measured at the cluster level; the outcome is continuous and measured at the individual level. The results show covariate imbalance results in negligible parameter bias and small standard error bias in adjusted linear mixed models. Ignoring the possibility of covariate imbalance while calculating the sample size at the cluster level may result in a loss in power of at most 25 % in the adjusted linear mixed model. The results are more severe for the unadjusted linear mixed model: parameter biases up to 100 % and standard error biases up to 200 % may be observed. Power levels based on the unadjusted linear mixed model are often too low. The consequences are most severe for large clusters and/or small intraclass correlation coefficients since then the required number of clusters to achieve a desired power level is smallest. The possibility of covariate imbalance should be taken into account while calculating the sample size of a cluster randomized trial. Otherwise more sophisticated methods to randomize clusters to treatments should be used, such as stratification or balance algorithms. All relevant covariates should be carefully identified, be actually measured and included in the statistical model to avoid severe levels of parameter and standard error bias and insufficient power levels.

  3. Miss Lora juveelikauplus = Miss Lora jewellery store

    Index Scriptorium Estoniae

    2009-01-01

    Narvas Fama kaubanduskeskuses (Tallinna mnt. 19c) asuva juveelikaupluse Miss Lora sisekujundusest. Sisearhitektid Annes Arro ja Hanna Karits. Poe sisu - vitriinkapid, vaip, valgustid - on valmistatud eritellimusel. Sisearhitektide tähtsamate tööde loetelu

  4. Principled Missing Data Treatments.

    Science.gov (United States)

    Lang, Kyle M; Little, Todd D

    2018-04-01

    We review a number of issues regarding missing data treatments for intervention and prevention researchers. Many of the common missing data practices in prevention research are still, unfortunately, ill-advised (e.g., use of listwise and pairwise deletion, insufficient use of auxiliary variables). Our goal is to promote better practice in the handling of missing data. We review the current state of missing data methodology and recent missing data reporting in prevention research. We describe antiquated, ad hoc missing data treatments and discuss their limitations. We discuss two modern, principled missing data treatments: multiple imputation and full information maximum likelihood, and we offer practical tips on how to best employ these methods in prevention research. The principled missing data treatments that we discuss are couched in terms of how they improve causal and statistical inference in the prevention sciences. Our recommendations are firmly grounded in missing data theory and well-validated statistical principles for handling the missing data issues that are ubiquitous in biosocial and prevention research. We augment our broad survey of missing data analysis with references to more exhaustive resources.

  5. Capturing and missing the patient's story through outcome measures: A thematic comparison of patient-generated items in PSYCHLOPS with CORE-OM and PHQ-9.

    Science.gov (United States)

    Sales, Célia Md; Neves, Inês Td; Alves, Paula G; Ashworth, Mark

    2017-11-22

    There is increasing interest in individualized patient-reported outcome measures (I-PROMS), where patients themselves indicate the specific problems they want to address in therapy and these problems are used as items within the outcome measurement tool. This paper examined the extent to which 279 items reported in an I-PROM (PSYCHLOPS) added qualitative information which was not captured by two well-established outcome measures (CORE-OM and PHQ-9). Comparison of items was only conducted for patients scoring above the "caseness" threshold on the standardized measures. 107 patients were participating in therapy within addiction and general psychiatric clinical settings. Almost every patient (95%) reported at least one item whose content was not covered by PHQ-9, and 71% reported at least one item not covered by CORE-OM. Results demonstrate the relevance of individualized outcome assessment for capturing data describing the issues of greatest concern to patients, as nomothetic measures do not always seem to capture the whole story. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

  6. Netbooks The Missing Manual

    CERN Document Server

    Biersdorfer, J

    2009-01-01

    Netbooks are the hot new thing in PCs -- small, inexpensive laptops designed for web browsing, email, and working with web-based programs. But chances are you don't know how to choose a netbook, let alone use one. Not to worry: with this Missing Manual, you'll learn which netbook is right for you and how to set it up and use it for everything from spreadsheets for work to hobbies like gaming and photo sharing. Netbooks: The Missing Manual provides easy-to-follow instructions and lots of advice to help you: Learn the basics for using a Windows- or Linux-based netbookConnect speakers, printe

  7. PCs The Missing Manual

    CERN Document Server

    Karp, David

    2005-01-01

    Your vacuum comes with one. Even your blender comes with one. But your PC--something that costs a whole lot more and is likely to be used daily and for tasks of far greater importance and complexity--doesn't come with a printed manual. Thankfully, that's not a problem any longer: PCs: The Missing Manual explains everything you need to know about PCs, both inside and out, and how to keep them running smoothly and working the way you want them to work. A complete PC manual for both beginners and power users, PCs: The Missing Manual has something for everyone. PC novices will appreciate the una

  8. Solving a binary puzzle

    NARCIS (Netherlands)

    Utomo, P.H.; Makarim, R.H.

    2017-01-01

    A Binary puzzle is a Sudoku-like puzzle with values in each cell taken from the set {0,1} {0,1}. Let n≥4 be an even integer, a solved binary puzzle is an n×n binary array that satisfies the following conditions: (1) no three consecutive ones and no three consecutive zeros in each row and each

  9. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  10. Proposed experiment to test fundamentally binary theories

    Science.gov (United States)

    Kleinmann, Matthias; Vértesi, Tamás; Cabello, Adán

    2017-09-01

    Fundamentally binary theories are nonsignaling theories in which measurements of many outcomes are constructed by selecting from binary measurements. They constitute a sensible alternative to quantum theory and have never been directly falsified by any experiment. Here we show that fundamentally binary theories are experimentally testable with current technology. For that, we identify a feasible Bell-type experiment on pairs of entangled qutrits. In addition, we prove that, for any n , quantum n -ary correlations are not fundamentally (n -1 ) -ary. For that, we introduce a family of inequalities that hold for fundamentally (n -1 ) -ary theories but are violated by quantum n -ary correlations.

  11. Mani, Miss Anna Modayil

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1960 Section: Earth & Planetary Sciences. Mani, Miss Anna Modayil A.I.I.Sc., FNA 1971-79; Secretary 1977-79. Date of birth: 23 August 1918. Date of death: 16 August 2001. Specialization: Atmospheric Physics and Instrumentation Last known address: c/o Mr K.T. Chandy, 14, ...

  12. Some 'Near Miss ' Experiences

    African Journals Online (AJOL)

    perienced health Workers, especially at lower level units, poor referral ... in the wards or operating theatre, and inability to access the busy health .... clinics, costs incurred and by who, who decided on hospitalisation, who .... pected pregnancy as I had missed my period the previous month. .... the patient received attention.

  13. The Missing Entrepreneurs 2014

    DEFF Research Database (Denmark)

    Halabisky, David; Potter, Jonathan; Thompson, Stuart

    OECD's LEED Programme and the European Commission's DG on Employment, Social Affairs and Inclusion recently published the second book as part of their programme of work on inclusive entrepreneurship. The Missing Entrepreneurs 2014 examines how public policies at national and local levels can...

  14. Non-negative Matrix Factorization for Binary Data

    DEFF Research Database (Denmark)

    Larsen, Jacob Søgaard; Clemmensen, Line Katrine Harder

    We propose the Logistic Non-negative Matrix Factorization for decomposition of binary data. Binary data are frequently generated in e.g. text analysis, sensory data, market basket data etc. A common method for analysing non-negative data is the Non-negative Matrix Factorization, though...... this is in theory not appropriate for binary data, and thus we propose a novel Non-negative Matrix Factorization based on the logistic link function. Furthermore we generalize the method to handle missing data. The formulation of the method is compared to a previously proposed method (Tome et al., 2015). We compare...... the performance of the Logistic Non-negative Matrix Factorization to Least Squares Non-negative Matrix Factorization and Kullback-Leibler (KL) Non-negative Matrix Factorization on sets of binary data: a synthetic dataset, a set of student comments on their professors collected in a binary term-document matrix...

  15. Near-miss maternal morbidity from severe haemorrhage at ...

    African Journals Online (AJOL)

    ... at caesarean section: A process and structure audit of system deficiencies in South Africa. ... The Donabedian model assumes that clinical outcomes are influenced by ... Dominant risk factors for near misses were previous caesarean section ...

  16. Prevalence and Correlates of Missed First Appointments among ...

    African Journals Online (AJOL)

    quality of care, results in poor treatment outcomes and drains financial resources. In Nigeria, where mental .... and physical aggression. Each subscale has four .... missed first appointments observed in this study falls within the range of 17 and ...

  17. Estimating range of influence in case of missing spatial data

    DEFF Research Database (Denmark)

    Bihrmann, Kristine; Ersbøll, Annette Kjær

    2015-01-01

    BACKGROUND: The range of influence refers to the average distance between locations at which the observed outcome is no longer correlated. In many studies, missing data occur and a popular tool for handling missing data is multiple imputation. The objective of this study was to investigate how...... the estimated range of influence is affected when 1) the outcome is only observed at some of a given set of locations, and 2) multiple imputation is used to impute the outcome at the non-observed locations. METHODS: The study was based on the simulation of missing outcomes in a complete data set. The range...... of influence was estimated from a logistic regression model with a spatially structured random effect, modelled by a Gaussian field. Results were evaluated by comparing estimates obtained from complete, missing, and imputed data. RESULTS: In most simulation scenarios, the range estimates were consistent...

  18. Missed opportunities in crystallography.

    Science.gov (United States)

    Dauter, Zbigniew; Jaskolski, Mariusz

    2014-09-01

    Scrutinized from the perspective of time, the giants in the history of crystallography more than once missed a nearly obvious chance to make another great discovery, or went in the wrong direction. This review analyzes such missed opportunities focusing on macromolecular crystallographers (using Perutz, Pauling, Franklin as examples), although cases of particular historical (Kepler), methodological (Laue, Patterson) or structural (Pauling, Ramachandran) relevance are also described. Linus Pauling, in particular, is presented several times in different circumstances, as a man of vision, oversight, or even blindness. His example underscores the simple truth that also in science incessant creativity is inevitably connected with some probability of fault. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  19. Miss World going deshi

    DEFF Research Database (Denmark)

    Wildermuth, Norbert

      In November 1996 the South Indian metropolis Bangalore hosted the annual Miss World show. The live event and its televisualisation became a prominent symbol for the India's economic liberalisation and for the immanent globalizing dimensions of this development. As such, the highly prestigious......, the pageant's contestation, which gave rise to a series of vehement protests and a broad public debate about the country's cultural alienation, marked a crucial point in time and trend towards the (re)localisation of the Indian television landscape. In consequence, the 1996 Miss World show and its...... their vision and politics of gender, nation and modernity on the larger Indian public, over the last two decades. Engaging the Indian population increasingly by way of the new electronic, c&s distributed media, competing discourses of gender and sexuality were projected, basically as a necessary, effective...

  20. The missed diagnosis

    International Nuclear Information System (INIS)

    Bundy, A.L.

    1988-01-01

    One of the questions that haunts the radiologist as he shuffles through piles of films is ''What am I missing?'' This same question takes on even more meaning when the radiologist is pressed for time, when he reluctantly checks the night work of the resident, when the patient left before more or better films could be obtained; or when the radiologist is involved in a subspecialty in which he is not properly trained. According to Dr. Berlin's survey, the missed diagnosis category accounted for the largest number of radiology malpractice cases. We all know that many diagnoses are more easily made using the ''retrospectoscope.'' But is the plaintiff attorney also adept at using this instrument? Just how knowledgeable must the radiologist be in the use of the ''prospectoscope''? A familiarity with cases that have already been tried should at least alert radiologists to the chances of their own involvement in litigation. While the missed diagnosis is by no means peculiar to the radiologist, it is one of the principal reasons that he may find himself in court

  1. Semiparametric Theory and Missing Data

    CERN Document Server

    Tsiatis, Anastasios A

    2006-01-01

    Missing data arise in almost all scientific disciplines. In many cases, missing data in an analysis is treated in a casual and ad-hoc manner, leading to invalid inferences and erroneous conclusions. This book summarizes knowledge regarding the theory of estimation for semiparametric models with missing data.

  2. Accounting for center in the Early External Cephalic Version trials: an empirical comparison of statistical methods to adjust for center in a multicenter trial with binary outcomes.

    Science.gov (United States)

    Reitsma, Angela; Chu, Rong; Thorpe, Julia; McDonald, Sarah; Thabane, Lehana; Hutton, Eileen

    2014-09-26

    Clustering of outcomes at centers involved in multicenter trials is a type of center effect. The Consolidated Standards of Reporting Trials Statement recommends that multicenter randomized controlled trials (RCTs) should account for center effects in their analysis, however most do not. The Early External Cephalic Version (EECV) trials published in 2003 and 2011 stratified by center at randomization, but did not account for center in the analyses, and due to the nature of the intervention and number of centers, may have been prone to center effects. Using data from the EECV trials, we undertook an empirical study to compare various statistical approaches to account for center effect while estimating the impact of external cephalic version timing (early or delayed) on the outcomes of cesarean section, preterm birth, and non-cephalic presentation at the time of birth. The data from the EECV pilot trial and the EECV2 trial were merged into one dataset. Fisher's exact method was used to test the overall effect of external cephalic version timing unadjusted for center effects. Seven statistical models that accounted for center effects were applied to the data. The models included: i) the Mantel-Haenszel test, ii) logistic regression with fixed center effect and fixed treatment effect, iii) center-size weighted and iv) un-weighted logistic regression with fixed center effect and fixed treatment-by-center interaction, iv) logistic regression with random center effect and fixed treatment effect, v) logistic regression with random center effect and random treatment-by-center interaction, and vi) generalized estimating equations. For each of the three outcomes of interest approaches to account for center effect did not alter the overall findings of the trial. The results were similar for the majority of the methods used to adjust for center, illustrating the robustness of the findings. Despite literature that suggests center effect can change the estimate of effect in

  3. Binary Masking & Speech Intelligibility

    DEFF Research Database (Denmark)

    Boldt, Jesper

    The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either experime......The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either...... experiments under ideal conditions or as experiments under more realistic conditions useful for real-life applications such as hearing aids. In the experiments under ideal conditions, the previously defined ideal binary mask is evaluated using hearing impaired listeners, and a novel binary mask -- the target...... binary mask -- is introduced. The target binary mask shows the same substantial increase in intelligibility as the ideal binary mask and is proposed as a new reference for binary masking. In the category of real-life applications, two new methods are proposed: a method for estimation of the ideal binary...

  4. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  5. The formation of eccentric compact binary inspirals and the role of gravitational wave emission in binary-single stellar encounters

    International Nuclear Information System (INIS)

    Samsing, Johan; MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2014-01-01

    The inspiral and merger of eccentric binaries leads to gravitational waveforms distinct from those generated by circularly merging binaries. Dynamical environments can assemble binaries with high eccentricity and peak frequencies within the LIGO band. In this paper, we study binary-single stellar scatterings occurring in dense stellar systems as a source of eccentrically inspiraling binaries. Many interactions between compact binaries and single objects are characterized by chaotic resonances in which the binary-single system undergoes many exchanges before reaching a final state. During these chaotic resonances, a pair of objects has a non-negligible probability of experiencing a very close passage. Significant orbital energy and angular momentum are carried away from the system by gravitational wave (GW) radiation in these close passages, and in some cases this implies an inspiral time shorter than the orbital period of the bound third body. We derive the cross section for such dynamical inspiral outcomes through analytical arguments and through numerical scattering experiments including GW losses. We show that the cross section for dynamical inspirals grows with increasing target binary semi-major axis a and that for equal-mass binaries it scales as a 2/7 . Thus, we expect wide target binaries to predominantly contribute to the production of these relativistic outcomes. We estimate that eccentric inspirals account for approximately 1% of dynamically assembled non-eccentric merging binaries. While these events are rare, we show that binary-single scatterings are a more effective formation channel than single-single captures for the production of eccentrically inspiraling binaries, even given modest binary fractions.

  6. Facebook The Missing Manual

    CERN Document Server

    Veer, E

    2011-01-01

    Facebook's spreading about as far and fast as the Web itself: 500 million members and counting. But there's a world of fun packed into the site that most folks miss. With this bestselling guide, learn how to unlock Facebook's talents as personal website creator, souped-up address book, and bustling community forum. It's an eye-opening, timesaving tour, guaranteed to help you get the most out of your Facebook experience. Coverage includes: Get started, get connected. Signing up is easy, but the real payoff comes when you tap into networks of coworkers, classmates, and friends. Pick and choose

  7. Mining frequent binary expressions

    NARCIS (Netherlands)

    Calders, T.; Paredaens, J.; Kambayashi, Y.; Mohania, M.K.; Tjoa, A.M.

    2000-01-01

    In data mining, searching for frequent patterns is a common basic operation. It forms the basis of many interesting decision support processes. In this paper we present a new type of patterns, binary expressions. Based on the properties of a specified binary test, such as reflexivity, transitivity

  8. Missed doses of oral antihyperglycemic medications in US adults with type 2 diabetes mellitus: prevalence and self-reported reasons.

    Science.gov (United States)

    Vietri, Jeffrey T; Wlodarczyk, Catherine S; Lorenzo, Rose; Rajpathak, Swapnil

    2016-09-01

    Adherence to antihyperglycemic medication is thought to be suboptimal, but the proportion of patients missing doses, the number of doses missed, and reasons for missing are not well described. This survey was conducted to estimate the prevalence of and reasons for missed doses of oral antihyperglycemic medications among US adults with type 2 diabetes mellitus, and to explore associations between missed doses and health outcomes. The study was a cross-sectional patient survey. Respondents were contacted via a commercial survey panel and completed an on-line questionnaire via the Internet. Respondents provided information about their use of oral antihyperglycemic medications including doses missed in the prior 4 weeks, personal characteristics, and health outcomes. Weights were calculated to project the prevalence to the US adult population with type 2 diabetes mellitus. Outcomes were compared according to number of doses missed in the past 4 weeks using bivariate statistics and generalized linear models. Approximately 30% of adult patients with type 2 diabetes mellitus reported missing or reducing ≥1 dose of oral antihyperglycemic medication in the prior 4 weeks. Accidental missing was more commonly reported than purposeful skipping, with forgetting the most commonly reported reason. The timing of missed doses suggested respondents had also forgotten about doses missed, so the prevalence of missed doses is likely higher than reported. Outcomes were poorer among those who reported missing three or more doses in the prior 4 weeks. A substantial number of US adults with type 2 diabetes mellitus miss doses of their oral antihyperglycemic medications.

  9. New or ν missing energy

    DEFF Research Database (Denmark)

    Franzosi, Diogo Buarque; Frandsen, Mads T.; Shoemaker, Ian M.

    2016-01-01

    flavor structures. Monojet data alone can be used to infer the mass of the "missing particle" from the shape of the missing energy distribution. In particular, 13 TeV LHC data will have sensitivity to DM masses greater than $\\sim$ 1 TeV. In addition to the monojet channel, NSI can be probed in multi......Missing energy signals such as monojets are a possible signature of Dark Matter (DM) at colliders. However, neutrino interactions beyond the Standard Model may also produce missing energy signals. In order to conclude that new "missing particles" are observed the hypothesis of BSM neutrino......-lepton searches which we find to yield stronger limits at heavy mediator masses. The sensitivity offered by these multi-lepton channels provide a method to reject or confirm the DM hypothesis in missing energy searches....

  10. Wikipedia the missing manual

    CERN Document Server

    Broughton, John

    2008-01-01

    Want to be part of the largest group-writing project in human history? Learn how to contribute to Wikipedia, the user-generated online reference for the 21st century. Considered more popular than eBay, Microsoft.com, and Amazon.com, Wikipedia servers respond to approximately 30,000 requests per second, or about 2.5 billion per day. It's become the first point of reference for people the world over who need a fact fast.If you want to jump on board and add to the content, Wikipedia: The Missing Manual is your first-class ticket. Wikipedia has more than 9 million entries in 250 languages, over 2

  11. Flexible Imputation of Missing Data

    CERN Document Server

    van Buuren, Stef

    2012-01-01

    Missing data form a problem in every scientific discipline, yet the techniques required to handle them are complicated and often lacking. One of the great ideas in statistical science--multiple imputation--fills gaps in the data with plausible values, the uncertainty of which is coded in the data itself. It also solves other problems, many of which are missing data problems in disguise. Flexible Imputation of Missing Data is supported by many examples using real data taken from the author's vast experience of collaborative research, and presents a practical guide for handling missing data unde

  12. Close binary stars

    International Nuclear Information System (INIS)

    Larsson-Leander, G.

    1979-01-01

    Studies of close binary stars are being persued more vigorously than ever, with about 3000 research papers and notes pertaining to the field being published during the triennium 1976-1978. Many major advances and spectacular discoveries were made, mostly due to increased observational efficiency and precision, especially in the X-ray, radio, and ultraviolet domains. Progress reports are presented in the following areas: observational techniques, methods of analyzing light curves, observational data, physical data, structure and models of close binaries, statistical investigations, and origin and evolution of close binaries. Reports from the Coordinates Programs Committee, the Committee for Extra-Terrestrial Observations and the Working Group on RS CVn binaries are included. (Auth./C.F.)

  13. Binary and ternary systems

    International Nuclear Information System (INIS)

    Petrov, D.A.

    1986-01-01

    Conditions for thermodynamical equilibrium in binary and ternary systems are considered. Main types of binary and ternary system phase diagrams are sequently constructed on the basis of general regularities on the character of transition from one equilibria to others. New statements on equilibrium line direction in the diagram triple points and their isothermal cross sections are developed. New represenations on equilibria in case of monovariant curve minimum and maximum on three-phase equilibrium formation in ternary system are introduced

  14. Planet formation in Binaries

    OpenAIRE

    Thebault, Ph.; Haghighipour, N.

    2014-01-01

    Spurred by the discovery of numerous exoplanets in multiple systems, binaries have become in recent years one of the main topics in planet formation research. Numerous studies have investigated to what extent the presence of a stellar companion can affect the planet formation process. Such studies have implications that can reach beyond the sole context of binaries, as they allow to test certain aspects of the planet formation scenario by submitting them to extreme environments. We review her...

  15. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    validity of any strategic equilibrium behavior, or even the customary independence axiom. We show that subjects sampled from our population are generally risk averse when lotteries are defined over monetary outcomes, and that the binary lottery procedure does indeed induce a statistically significant shift......We evaluate the binary lottery procedure for inducing risk neutral behavior. We strip the experimental implementation down to bare bones, taking care to avoid any potentially confounding assumptions about behavior having to be made. In particular, our evaluation does not rely on the assumed...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  16. Missing Value Imputation Based on Gaussian Mixture Model for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Xiaobo Yan

    2015-01-01

    Full Text Available This paper addresses missing value imputation for the Internet of Things (IoT. Nowadays, the IoT has been used widely and commonly by a variety of domains, such as transportation and logistics domain and healthcare domain. However, missing values are very common in the IoT for a variety of reasons, which results in the fact that the experimental data are incomplete. As a result of this, some work, which is related to the data of the IoT, can’t be carried out normally. And it leads to the reduction in the accuracy and reliability of the data analysis results. This paper, for the characteristics of the data itself and the features of missing data in IoT, divides the missing data into three types and defines three corresponding missing value imputation problems. Then, we propose three new models to solve the corresponding problems, and they are model of missing value imputation based on context and linear mean (MCL, model of missing value imputation based on binary search (MBS, and model of missing value imputation based on Gaussian mixture model (MGI. Experimental results showed that the three models can improve the accuracy, reliability, and stability of missing value imputation greatly and effectively.

  17. The effect of tertiary surveys on missed injuries in trauma: a systematic review

    Directory of Open Access Journals (Sweden)

    Keijzers Gerben B

    2012-11-01

    Full Text Available Abstract Background Trauma tertiary surveys (TTS are advocated to reduce the rate of missed injuries in hospitalized trauma patients. Moreover, the missed injury rate can be a quality indicator of trauma care performance. Current variation of the definition of missed injury restricts interpretation of the effect of the TTS and limits the use of missed injury for benchmarking. Only a few studies have specifically assessed the effect of the TTS on missed injury. We aimed to systematically appraise these studies using outcomes of two common definitions of missed injury rates and long-term health outcomes. Methods A systematic review was performed. An electronic search (without language or publication restrictions of the Cochrane Library, Medline and Ovid was used to identify studies assessing TTS with short-term measures of missed injuries and long-term health outcomes. ‘Missed injury’ was defined as either: Type I any injury missed at primary and secondary survey and detected by the TTS; or Type II any injury missed at primary and secondary survey and missed by the TTS, detected during hospital stay. Two authors independently selected studies. Risk of bias for observational studies was assessed using the Newcastle-Ottawa scale. Results Ten observational studies met our inclusion criteria. None was randomized and none reported long-term health outcomes. Their risk of bias varied considerably. Nine studies assessed Type I missed injury and found an overall rate of 4.3%. A single study reported Type II missed injury with a rate of 1.5%. Three studies reported outcome data on missed injuries for both control and intervention cohorts, with two reporting an increase in Type I missed injuries (3% vs. 7%, PP=0.01. Conclusions Overall Type I and Type II missed injury rates were 4.3% and 1.5%. Routine TTS performance increased Type I and reduced Type II missed injuries. However, evidence is sub-optimal: few observational studies, non-uniform outcome

  18. Conversations with Miss Jane

    Directory of Open Access Journals (Sweden)

    Geneviève Fabre

    2006-05-01

    Full Text Available Considering the wide range of conversations in the autobiography, this essay will attempt to appraise the importance of these verbal exchanges in relation to the overall narrative structure of the book and to the prevalent oral tradition in Louisiana culture, as both an individual and communal expression. The variety of circumstances, the setting and staging, the interlocutors , and the complex intersection of time and place, of stories and History, will be examined; in these conversations with Miss Jane many actors participate, from  the interviewer-narrator, to most characters; even the reader becomes involved.Speaking, hearing, listening, keeping silent is an elaborate ritual that performs many functions; besides conveying news or rumors, it imparts information on the times and on the life of a “representative” woman whose existence - spanning a whole century- is both singular and emblematic. Most importantly this essay will analyse the resonance of an eventful and often dramatic era on her sensibility and conversely show how her evolving sensibility informs that history and draws attention to aspects that might have passed unnoticed or be forever silenced. Jane’s desire for liberty and justice is often challenged as she faces the possibilities of life or death.Conversations build up a complex, often contradictory, but compelling portrait: torn between silence and vehemence, between memories and the urge to meet the future, Jane summons body and mind to find her way through the maze of a fast changing world; self-willed and obstinate she claims her right to speak, to express with wit and wisdom her firm belief in the word, in the ability to express deep seated convictions and faith and a whole array of feelings and emotions.

  19. Known and missing left ventricular ejection fraction and survival in patients with heart failure

    DEFF Research Database (Denmark)

    Poppe, Katrina K; Squire, Iain B; Whalley, Gillian A

    2013-01-01

    Treatment of patients with heart failure (HF) relies on measurement of LVEF. However, the extent to which EF is recorded varies markedly. We sought to characterize the patient group that is missing a measure of EF, and to explore the association between missing EF and outcome.......Treatment of patients with heart failure (HF) relies on measurement of LVEF. However, the extent to which EF is recorded varies markedly. We sought to characterize the patient group that is missing a measure of EF, and to explore the association between missing EF and outcome....

  20. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  1. Optimal simultaneous superpositioning of multiple structures with missing data.

    Science.gov (United States)

    Theobald, Douglas L; Steindel, Phillip A

    2012-08-01

    Superpositioning is an essential technique in structural biology that facilitates the comparison and analysis of conformational differences among topologically similar structures. Performing a superposition requires a one-to-one correspondence, or alignment, of the point sets in the different structures. However, in practice, some points are usually 'missing' from several structures, for example, when the alignment contains gaps. Current superposition methods deal with missing data simply by superpositioning a subset of points that are shared among all the structures. This practice is inefficient, as it ignores important data, and it fails to satisfy the common least-squares criterion. In the extreme, disregarding missing positions prohibits the calculation of a superposition altogether. Here, we present a general solution for determining an optimal superposition when some of the data are missing. We use the expectation-maximization algorithm, a classic statistical technique for dealing with incomplete data, to find both maximum-likelihood solutions and the optimal least-squares solution as a special case. The methods presented here are implemented in THESEUS 2.0, a program for superpositioning macromolecular structures. ANSI C source code and selected compiled binaries for various computing platforms are freely available under the GNU open source license from http://www.theseus3d.org. dtheobald@brandeis.edu Supplementary data are available at Bioinformatics online.

  2. Modelling binary data

    CERN Document Server

    Collett, David

    2002-01-01

    INTRODUCTION Some Examples The Scope of this Book Use of Statistical Software STATISTICAL INFERENCE FOR BINARY DATA The Binomial Distribution Inference about the Success Probability Comparison of Two Proportions Comparison of Two or More Proportions MODELS FOR BINARY AND BINOMIAL DATA Statistical Modelling Linear Models Methods of Estimation Fitting Linear Models to Binomial Data Models for Binomial Response Data The Linear Logistic Model Fitting the Linear Logistic Model to Binomial Data Goodness of Fit of a Linear Logistic Model Comparing Linear Logistic Models Linear Trend in Proportions Comparing Stimulus-Response Relationships Non-Convergence and Overfitting Some other Goodness of Fit Statistics Strategy for Model Selection Predicting a Binary Response Probability BIOASSAY AND SOME OTHER APPLICATIONS The Tolerance Distribution Estimating an Effective Dose Relative Potency Natural Response Non-Linear Logistic Regression Models Applications of the Complementary Log-Log Model MODEL CHECKING Definition of Re...

  3. Evolution of dwarf binaries

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Fedorova, A.V.; Yungel'son, L.R.

    1982-01-01

    The conditions of mass exchange in close binary systems with masses of components less or equal to one solar mass have been analysed for the case, when the system radiates gravitational waves. It has been shown that the mass exchange rate depends in a certain way on the mass ratio of components and on the mass of component that fills its inner critical lobe. The comparison of observed periods, masses of contact components, and mass exchange rates of observed cataclysmic binaries have led to the conclusion that the evolution of close binaries WZ Sge, OY Car, Z Cha, TT Ari, 2A 0311-227, and G 61-29 may be driven by the emission of gravitational waves [ru

  4. Binary catalogue of exoplanets

    Science.gov (United States)

    Schwarz, Richard; Bazso, Akos; Zechner, Renate; Funk, Barbara

    2016-02-01

    Since 1995 there is a database which list most of the known exoplanets (The Extrasolar Planets Encyclopaedia at http://exoplanet.eu/). With the growing number of detected exoplanets in binary and multiple star systems it became more important to mark and to separate them into a new database, which is not available in the Extrasolar Planets Encyclopaedia. Therefore we established an online database (which can be found at: http://www.univie.ac.at/adg/schwarz/multiple.html) for all known exoplanets in binary star systems and in addition for multiple star systems, which will be updated regularly and linked to the Extrasolar Planets Encyclopaedia. The binary catalogue of exoplanets is available online as data file and can be used for statistical purposes. Our database is divided into two parts: the data of the stars and the planets, given in a separate list. We describe also the different parameters of the exoplanetary systems and present some applications.

  5. Binary and Millisecond Pulsars.

    Science.gov (United States)

    Lorimer, Duncan R

    2008-01-01

    We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5 M ⊙ , a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric ( e = 0.44) orbit around an unevolved companion. Supplementary material is available for this article at 10.12942/lrr-2008-8.

  6. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2008-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5M_⊙, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e = 0.44 orbit around an unevolved companion.

  7. Dissipative binary collisions

    International Nuclear Information System (INIS)

    Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.

    1998-01-01

    The binary character of the heavy ion collisions at intermediate energies in the exit channel has been observed under 30 MeV/n in medium and heavy systems. Measurements in light systems at energies approaching ∼ 100 MeV/nucleon as well as in very heavy systems have allowed to extend considerably the investigations of this binary process. Thus, the study of the Pb + Au system showed that the complete charge events indicated two distinct sources: the quasi-projectile and the quasi-target. The characteristics of these two sources are rather well reproduced by a trajectory computation which takes into account the Coulomb and nuclear forces and the friction appearing from the projectile-target interaction. The Wilczynski diagram is used to probe the correlation between the kinetic energy quenching and the deflecting angle. In case of the system Pb + Au at 29 MeV/nucleon the diagram indicate dissipative binary collisions typical for low energies. This binary aspect was also detected in the systems Xe + Ag at 44 MeV/nucleon, 36 Ar + 27 Al and 64 Zn + nat Ti. Thus, it was possible to reconstruct the quasi-projectile and to study its mass and excitation energy evolution as a function of the impact parameter. The dissipative binary collisions represent for the systems and energies under considerations the main contribution to the cross section. This does not implies that there are not other processes; particularly, the more or less complete fusion is also observed but with a low cross section which decreases with the increase of bombardment energy. More exclusive measurements with the INDRA detector on quasi-symmetric systems as Ar + KCl and Xe + Sn seem to confirm the importance of the binary collisions. The two source reconstruction of the Xe + Sn data at 50 MeV/nucleon reproduces the same behaviour as that observed in the system Pb + Au at 29 MeV/nucleon

  8. PHYSICS OF ECLIPSING BINARIES. II. TOWARD THE INCREASED MODEL FIDELITY

    Energy Technology Data Exchange (ETDEWEB)

    Prša, A.; Conroy, K. E.; Horvat, M.; Kochoska, A.; Hambleton, K. M. [Villanova University, Dept. of Astrophysics and Planetary Sciences, 800 E Lancaster Avenue, Villanova PA 19085 (United States); Pablo, H. [Université de Montréal, Pavillon Roger-Gaudry, 2900, boul. Édouard-Montpetit Montréal QC H3T 1J4 (Canada); Bloemen, S. [Radboud University Nijmegen, Department of Astrophysics, IMAPP, P.O. Box 9010, 6500 GL, Nijmegen (Netherlands); Giammarco, J. [Eastern University, Dept. of Astronomy and Physics, 1300 Eagle Road, St. Davids, PA 19087 (United States); Degroote, P. [KU Leuven, Instituut voor Sterrenkunde, Celestijnenlaan 200D, B-3001 Heverlee (Belgium)

    2016-12-01

    The precision of photometric and spectroscopic observations has been systematically improved in the last decade, mostly thanks to space-borne photometric missions and ground-based spectrographs dedicated to finding exoplanets. The field of eclipsing binary stars strongly benefited from this development. Eclipsing binaries serve as critical tools for determining fundamental stellar properties (masses, radii, temperatures, and luminosities), yet the models are not capable of reproducing observed data well, either because of the missing physics or because of insufficient precision. This led to a predicament where radiative and dynamical effects, insofar buried in noise, started showing up routinely in the data, but were not accounted for in the models. PHOEBE (PHysics Of Eclipsing BinariEs; http://phoebe-project.org) is an open source modeling code for computing theoretical light and radial velocity curves that addresses both problems by incorporating missing physics and by increasing the computational fidelity. In particular, we discuss triangulation as a superior surface discretization algorithm, meshing of rotating single stars, light travel time effects, advanced phase computation, volume conservation in eccentric orbits, and improved computation of local intensity across the stellar surfaces that includes the photon-weighted mode, the enhanced limb darkening treatment, the better reflection treatment, and Doppler boosting. Here we present the concepts on which PHOEBE is built and proofs of concept that demonstrate the increased model fidelity.

  9. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2005-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1700. There are now 80 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 103 pulsars in 24 of the Galactic globular clusters. Recent highlights have been the discovery of the first ever double pulsar system and a recent flurry of discoveries in globular clusters, in particular Terzan 5.

  10. Association of the Nurse Work Environment, Collective Efficacy, and Missed Care.

    Science.gov (United States)

    Smith, Jessica G; Morin, Karen H; Wallace, Leigh E; Lake, Eileen T

    2018-06-01

    Missed nursing care is a significant threat to quality patient care. Promoting collective efficacy within nurse work environments could decrease missed care. The purpose was to understand how missed care is associated with nurse work environments and collective efficacy of hospital staff nurses. A cross-sectional, convenience sample was obtained through online surveys from registered nurses working at five southwestern U.S. hospitals. Descriptive, correlational, regression, and path analyses were conducted ( N = 233). The percentage of nurses who reported that at least one care activity was missed frequently or always was 94%. Mouth care (36.0% of nurses) and ambulation (35.3%) were missed frequently or always. Nurse work environments and collective efficacy were moderately, positively correlated. Nurse work environments and collective efficacy were associated with less missed care (χ 2 = 10.714, p = .0054). Fostering collective efficacy in the nurse work environment could reduce missed care and improve patient outcomes.

  11. Equational binary decision diagrams

    NARCIS (Netherlands)

    J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

    2000-01-01

    textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and

  12. Binary tense and modality

    NARCIS (Netherlands)

    Broekhuis, H.; Verkuyl, H.J

    2014-01-01

    The present paper adopts as its point of departure the claim by Te Winkel (1866) and Verkuyl (2008) that mental temporal representations are built on the basis of three binary oppositions: Present/Past, Synchronous/Posterior and Imperfect/Perfect. Te Winkel took the second opposition in terms of the

  13. N-Bit Binary Resistor

    Science.gov (United States)

    Tcheng, Ping

    1989-01-01

    Binary resistors in series tailored to precise value of resistance. Desired value of resistance obtained by cutting appropriate traces across resistors. Multibit, binary-based, adjustable resistor with high resolution used in many applications where precise resistance required.

  14. Altering the "Near-Miss" Effect in Slot Machine Gamblers

    Science.gov (United States)

    Dixon, Mark R.; Nastally, Becky L.; Jackson, James E.; Habib, Reza

    2009-01-01

    This study investigated the potential for recreational gamblers to respond as if certain types of losing slot machine outcomes were actually closer to a win than others (termed the "near-miss effect"). Exposure to conditional discrimination training and testing disrupted this effect for 10 of the 16 participants. These 10 participants demonstrated…

  15. Bayesian informative dropout model for longitudinal binary data with random effects using conditional and joint modeling approaches.

    Science.gov (United States)

    Chan, Jennifer S K

    2016-05-01

    Dropouts are common in longitudinal study. If the dropout probability depends on the missing observations at or after dropout, this type of dropout is called informative (or nonignorable) dropout (ID). Failure to accommodate such dropout mechanism into the model will bias the parameter estimates. We propose a conditional autoregressive model for longitudinal binary data with an ID model such that the probabilities of positive outcomes as well as the drop-out indicator in each occasion are logit linear in some covariates and outcomes. This model adopting a marginal model for outcomes and a conditional model for dropouts is called a selection model. To allow for the heterogeneity and clustering effects, the outcome model is extended to incorporate mixture and random effects. Lastly, the model is further extended to a novel model that models the outcome and dropout jointly such that their dependency is formulated through an odds ratio function. Parameters are estimated by a Bayesian approach implemented using the user-friendly Bayesian software WinBUGS. A methadone clinic dataset is analyzed to illustrate the proposed models. Result shows that the treatment time effect is still significant but weaker after allowing for an ID process in the data. Finally the effect of drop-out on parameter estimates is evaluated through simulation studies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  17. Learning to assign binary weights to binary descriptor

    Science.gov (United States)

    Huang, Zhoudi; Wei, Zhenzhong; Zhang, Guangjun

    2016-10-01

    Constructing robust binary local feature descriptors are receiving increasing interest due to their binary nature, which can enable fast processing while requiring significantly less memory than their floating-point competitors. To bridge the performance gap between the binary and floating-point descriptors without increasing the computational cost of computing and matching, optimal binary weights are learning to assign to binary descriptor for considering each bit might contribute differently to the distinctiveness and robustness. Technically, a large-scale regularized optimization method is applied to learn float weights for each bit of the binary descriptor. Furthermore, binary approximation for the float weights is performed by utilizing an efficient alternatively greedy strategy, which can significantly improve the discriminative power while preserve fast matching advantage. Extensive experimental results on two challenging datasets (Brown dataset and Oxford dataset) demonstrate the effectiveness and efficiency of the proposed method.

  18. Missed hormonal contraceptives: new recommendations.

    Science.gov (United States)

    Guilbert, Edith; Black, Amanda; Dunn, Sheila; Senikas, Vyta

    2008-11-01

    To provide evidence-based guidance for women and their health care providers on the management of missed or delayed hormonal contraceptive doses in order to prevent unintended pregnancy. Medline, PubMed, and the Cochrane Database were searched for articles published in English, from 1974 to 2007, about hormonal contraceptive methods that are available in Canada and that may be missed or delayed. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. The quality of evidence is rated using the criteria developed by the Canadian Task Force on Preventive Health Care. This committee opinion will help health care providers offer clear information to women who have not been adherent in using hormonal contraception with the purpose of preventing unintended pregnancy. The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: 1. Instructions for what women should do when they miss hormonal contraception have been complex and women do not understand them correctly. (I) 2. The highest risk of ovulation occurs when the hormone-free interval is prolonged for more than seven days, either by delaying the start of combined hormonal contraceptives or by missing active hormone doses during the first or third weeks of combined oral contraceptives. (II) Ovulation rarely occurs after seven consecutive days of combined oral contraceptive use. (II) RECOMMENDATIONS: 1. Health care providers should give clear, simple instructions, both written and oral, on missed hormonal contraceptive pills as part of contraceptive counselling. (III-A) 2. Health care providers should provide women with telephone/electronic resources for reference in the event of missed or delayed hormonal contraceptives. (III-A) 3. In order to avoid an increased risk of unintended pregnancy, the hormone-free interval should not exceed seven days in combined hormonal contraceptive users. (II-A) 4. Back-up contraception should

  19. Effects of Missing Data Methods in SEM under Conditions of Incomplete and Nonnormal Data

    Science.gov (United States)

    Li, Jian; Lomax, Richard G.

    2017-01-01

    Using Monte Carlo simulations, this research examined the performance of four missing data methods in SEM under different multivariate distributional conditions. The effects of four independent variables (sample size, missing proportion, distribution shape, and factor loading magnitude) were investigated on six outcome variables: convergence rate,…

  20. Droid X The Missing Manual

    CERN Document Server

    Gralla, Preston

    2011-01-01

    Get the most from your Droid X right away with this entertaining Missing Manual. Veteran tech author Preston Gralla offers a guided tour of every feature, with lots of expert tips and tricks along the way. You'll learn how to use calling and texting features, take and share photos, enjoy streaming music and video, and much more. Packed with full-color illustrations, this engaging book covers everything from getting started to advanced features and troubleshooting. Unleash the power of Motorola's hot new device with Droid X: The Missing Manual. Get organized. Import your contacts and sync wit

  1. Motorola Xoom The Missing Manual

    CERN Document Server

    Gralla, Preston

    2011-01-01

    Motorola Xoom is the first tablet to rival the iPad, and no wonder with all of the great features packed into this device. But learning how to use everything can be tricky-and Xoom doesn't come with a printed guide. That's where this Missing Manual comes in. Gadget expert Preston Gralla helps you master your Xoom with step-by-step instructions and clear explanations. As with all Missing Manuals, this book offers refreshing, jargon-free prose and informative illustrations. Use your Xoom as an e-book reader, music player, camcorder, and phoneKeep in touch with email, video and text chat, and so

  2. Prevalence of maternal near miss and community-based risk factors in Central Uganda.

    Science.gov (United States)

    Nansubuga, Elizabeth; Ayiga, Natal; Moyer, Cheryl A

    2016-11-01

    To examine the prevalence of maternal near-miss (MNM) and its associated risk factors in a community setting in Central Uganda. A cross-sectional research design employing multi-stage sampling collected data from women aged 15-49 years in Rakai, Uganda, who had been pregnant in the 3years preceding the survey, conducted between August 10 and December 31, 2013. Additionally, in-depth interviews were conducted. WHO-based disease and management criteria were used to identify MNM. Binary logistic regression was used to predict MNM risk factors. Content analysis was performed for qualitative data. Survey data were collected from 1557 women and 40 in-depth interviews were conducted. The MNM prevalence was 287.7 per 1000 pregnancies; the majority of MNMs resulted from hemorrhage. Unwanted pregnancies, a history of MNM, primipara, pregnancy danger signs, Banyakore ethnicity, and a partner who had completed primary education only were associated with increased odds of MNM (all Pstudies employing organ-failure MNM-diagnostic criteria. These findings illustrate the need to look beyond mortality statistics when assessing maternal health outcomes. Concerted efforts to increase supervised deliveries, access to emergency obstetric care, and access to contraceptives are warranted. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Processing Of Binary Images

    Science.gov (United States)

    Hou, H. S.

    1985-07-01

    An overview of the recent progress in the area of digital processing of binary images in the context of document processing is presented here. The topics covered include input scan, adaptive thresholding, halftoning, scaling and resolution conversion, data compression, character recognition, electronic mail, digital typography, and output scan. Emphasis has been placed on illustrating the basic principles rather than descriptions of a particular system. Recent technology advances and research in this field are also mentioned.

  4. Did you miss the eclipse?

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    Not wanting to miss a moment of the beautiful celestial dance that played out on Friday, 20 March, Jens Roder of CERN’s PH group took to the Jura mountains, where he got several shots of the event. Here are a selection of his photos, which he was kind enough to share with the Bulletin and its readers.  

  5. Missing Boxes in Central Europe

    DEFF Research Database (Denmark)

    Prockl, Günter; Weibrecht Kristensen, Kirsten

    2015-01-01

    The Chinese New Year is an event that obviously happens every year. Every year however it also causes severe problems for the companies involved in the industry in form of missing containers throughout the chain but in particular in the European Hinterland. Illustrated on the symptoms of the Chin...

  6. Medical surgical nurses describe missed nursing care tasks-Evaluating our work environment.

    Science.gov (United States)

    Winsett, Rebecca P; Rottet, Kendra; Schmitt, Abby; Wathen, Ellen; Wilson, Debra

    2016-11-01

    The purpose of the study was to explore the nurse work environment by evaluating the self-report of missed nursing care and the reasons for the missed care. A convenience sample of medical surgical nurses from four hospitals was invited to complete the survey for this descriptive study. The sample included 168 nurses. The MISSCARE survey assessed the frequency and reason of 24 routine nursing care elements. The most frequently reported missed care was ambulation as ordered, medications given within a 30 minute window, and mouth care. Moderate or significant reasons reported for the missed care were: unexpected rise in volume/acuity, heavy admissions/discharges, inadequate assistants, inadequate staff, meds not available when needed, and urgent situations. Identifying missed nursing care and reasons for missed care provides an opportunity for exploring strategies to reduce interruptions, develop unit cohesiveness, improve the nurse work environment, and ultimately leading to improved patient outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Formation and Evolution of X-ray Binaries

    Science.gov (United States)

    Shao, Y.

    2017-07-01

    use of both binary population synthesis and detailed binary evolution calculations. We find that the birthrate is around 10-4 yr-1 for the incipient X-ray binaries in both cases. We demonstrate the distribution of the ULX population in the donor mass - orbital period plane. Our results suggest that, compared with black hole X-ray binaries, neutron star X-ray binaries may significantly contribute to the ULX population, and high/intermediate-mass X-ray binaries dominate the neutron star ULX population in M82/Milky Way-like galaxies, respectively. In Chapter 6, the population of intermediate- and low-mass X-ray binaries in the Galaxy is explored. We investigate the formation and evolutionary sequences of Galactic intermediate- and low-mass X-ray binaries by combining binary population synthesis (BPS) and detailed stellar evolutionary calculations. Using an updated BPS code we compute the evolution of massive binaries that leads to the formation of incipient I/LMXBs, and present their distribution in the initial donor mass vs. initial orbital period diagram. We then follow the evolution of I/LMXBs until the formation of binary millisecond pulsars (BMSPs). We show that during the evolution of I/LMXBs they are likely to be observed as relatively compact binaries. The resultant BMSPs have orbital periods ranging from about 1 day to a few hundred days. These features are consistent with observations of LMXBs and BMSPs. We also confirm the discrepancies between theoretical predictions and observations mentioned in the literature, that is, the theoretical average mass transfer rates of LMXBs are considerably lower than observed, and the number of BMSPs with orbital periods ˜ 0.1-1 \\unit{d} is severely underestimated. Both imply that something is missing in the modeling of LMXBs, which is likely to be related to the mechanisms of the orbital angular momentum loss. Finally in Chapter 7 we summarize our results and give the prospects for the future work.

  8. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  9. A Stochastic Method to Manage Delay and Missing Values for In-Situ Sensors in an Alternating Activated Sludge Process

    DEFF Research Database (Denmark)

    Stentoft, Peter Alexander; Munk-Nielsen, Thomas; Mikkelsen, Peter Steen

    2017-01-01

    . The measurements may also be temporarily unavailable because of recalibration, communication faults or other errors. Here we present a method that handles such delay and missing observations. The model is based on zero order hold stochastic differential equations which use binary signals for influent flow...

  10. Moderation analysis with missing data in the predictors.

    Science.gov (United States)

    Zhang, Qian; Wang, Lijuan

    2017-12-01

    The most widely used statistical model for conducting moderation analysis is the moderated multiple regression (MMR) model. In MMR modeling, missing data could pose a challenge, mainly because the interaction term is a product of two or more variables and thus is a nonlinear function of the involved variables. In this study, we consider a simple MMR model, where the effect of the focal predictor X on the outcome Y is moderated by a moderator U. The primary interest is to find ways of estimating and testing the moderation effect with the existence of missing data in X. We mainly focus on cases when X is missing completely at random (MCAR) and missing at random (MAR). Three methods are compared: (a) Normal-distribution-based maximum likelihood estimation (NML); (b) Normal-distribution-based multiple imputation (NMI); and (c) Bayesian estimation (BE). Via simulations, we found that NML and NMI could lead to biased estimates of moderation effects under MAR missingness mechanism. The BE method outperformed NMI and NML for MMR modeling with missing data in the focal predictor, missingness depending on the moderator and/or auxiliary variables, and correctly specified distributions for the focal predictor. In addition, more robust BE methods are needed in terms of the distribution mis-specification problem of the focal predictor. An empirical example was used to illustrate the applications of the methods with a simple sensitivity analysis. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Binary optics: Trends and limitations

    Science.gov (United States)

    Farn, Michael W.; Veldkamp, Wilfrid B.

    1993-01-01

    We describe the current state of binary optics, addressing both the technology and the industry (i.e., marketplace). With respect to the technology, the two dominant aspects are optical design methods and fabrication capabilities, with the optical design problem being limited by human innovation in the search for new applications and the fabrication issue being limited by the availability of resources required to improve fabrication capabilities. With respect to the industry, the current marketplace does not favor binary optics as a separate product line and so we expect that companies whose primary purpose is the production of binary optics will not represent the bulk of binary optics production. Rather, binary optics' more natural role is as an enabling technology - a technology which will directly result in a competitive advantage in a company's other business areas - and so we expect that the majority of binary optics will be produced for internal use.

  12. Particle acceleration in binaries

    Directory of Open Access Journals (Sweden)

    Sinitsyna V.G.

    2017-01-01

    Full Text Available Cygnus X-3 massive binary system is one of the powerful sources of radio and X-ray emission consisting of an accreting compact object, probably a black hole, with a Wolf-Rayet star companion. Based on the detections of ultra high energy gamma-rays by Kiel and Havera Park, Cygnus X-3 has been proposed to be one of the most powerful sources of charged cosmic ray particles in the Galaxy. The results of long-term observations of the Cyg X-3 binary at energies 800 GeV–85 TeV detected by SHALON in 1995 are presented with images, integral spectra and spectral energy distribution. The identification of source with Cygnus X-3 detected by SHALON was secured by the detection of its 4.8 hour orbital period in TeV gamma-rays. During the whole observation period of Cyg X-3 with SHALON significant flux increases were detected at energies above 0.8 TeV. These TeV flux increases are correlated with flaring activity at a lower energy range of X-ray and/or at observations of Fermi LAT as well as with radio emission from the relativistic jets of Cygnus X-3. The variability of very high-energy gamma-radiation and correlation of radiation activity in the wide energy range can provide essential information on particle mechanism production up to very high energies. Whereas, modulation of very high energy emission connected to the orbital motion of the binary system, provides an understanding of the emission processes, nature and location of particle acceleration.

  13. Miss Julie: A Psychoanalytic Study

    Directory of Open Access Journals (Sweden)

    Sonali Jain

    2015-10-01

    Full Text Available Sigmund Freud theorized that ‘the hero of the tragedy must suffer…to bear the burden of tragic guilt…(that lay in rebellion against some divine or human authority.’ August Strindberg, the Swedish poet, playwright, author and visual artist, like Shakespeare before him, portrayed insanity as the ultimate of tragic conflict. In this paper I seek to explore and reiterate the dynamics of human relationships that are as relevant today as they were in Strindberg’s time. I propose to examine Strindberg’s Miss Julie, a play set in nineteenth century Sweden, through a psychoanalytic lens. The play deals with bold themes of class and sexual identity politics. Notwithstanding the progress made in breaking down gender barriers, the inequalities inherent in a patriarchal system persist in modern society. Miss Julie highlights these imbalances. My analysis of the play deals with issues of culture and psyche, and draws on Freud, Melanie Klein, Lacan, Luce Irigaray and other contemporary feminists. Miss Julie is a discourse on hysteria, which is still pivotal to psychoanalysis. Prominent philosophers like Hegel and the psychoanalyst Jacques Lacan have written about the dialectic of the master and the slave – a relationship that is characterized by dependence, demand and cruelty. The history of human civilization shows beyond any doubt that there is an intimate connection between cruelty and the sexual instinct. An analysis of the text is carried out using the sado-masochistic dynamic as well the slave-master discourse. I argue that Miss Julie subverts the slave-master relationship. The struggle for dominance and power is closely linked with the theme of sexuality in the unconscious. To quote the English actor and director Alan Rickman, ‘Watching or working on the plays of Strindberg is like seeing the skin, flesh and bones of life separated from each other. Challenging and timeless.’

  14. Magnetic binary nanofillers

    International Nuclear Information System (INIS)

    Morales Mendoza, N.; Goyanes, S.; Chiliotte, C.; Bekeris, V.; Rubiolo, G.; Candal, R.

    2012-01-01

    Magnetic binary nanofillers containing multiwall carbon nanotubes (MWCNT) and hercynite were synthesized by Chemical Vapor Deposition (CVD) on Fe/AlOOH prepared by the sol-gel method. The catalyst precursor was fired at 450 °C, ground and sifted through different meshes. Two powders were obtained with different particle sizes: sample A (50-75 μm) and sample B (smaller than 50 μm). These powders are composed of iron oxide particles widely dispersed in the non-crystalline matrix of aluminum oxide and they are not ferromagnetic. After reduction process the powders are composed of α-Fe nanoparticles inside hercynite matrix. These nanofillers are composed of hercynite containing α-Fe nanoparticles and MWCNT. The binary magnetic nanofillers were slightly ferromagnetic. The saturation magnetization of the nanofillers depended on the powder particle size. The nanofiller obtained from powder particles in the range 50-75 μm showed a saturation magnetization 36% higher than the one formed from powder particles smaller than 50 μm. The phenomenon is explained in terms of changes in the magnetic environment of the particles as consequence of the presence of MWCNT.

  15. Magnetic binary nanofillers

    Energy Technology Data Exchange (ETDEWEB)

    Morales Mendoza, N. [INQUIMAE, CONICET-UBA, Ciudad Universitaria, Pab2, (C1428EHA) Bs As (Argentina); LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Goyanes, S. [LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Chiliotte, C.; Bekeris, V. [LBT, Dep. De Fisica, FCEN-UBA. Ciudad Universitaria, Pab1, C1428EGA CABA (Argentina); Rubiolo, G. [LPyMC, Dep. De Fisica, FCEN-UBA and IFIBA -CONICET, Ciudad Universitaria, Cap. Fed. (Argentina); Unidad de Actividad Materiales, CNEA, Av Gral. Paz 1499, San Martin (1650), Prov. de Bs As (Argentina); Candal, R., E-mail: candal@qi.fcen.uba.ar [INQUIMAE, CONICET-UBA, Ciudad Universitaria, Pab2, (C1428EHA) Bs As (Argentina); Escuela de Ciencia y Tecnologia, 3iA, Universidad de Gral. San Martin, San Martin, Prov. Bs As (Argentina)

    2012-08-15

    Magnetic binary nanofillers containing multiwall carbon nanotubes (MWCNT) and hercynite were synthesized by Chemical Vapor Deposition (CVD) on Fe/AlOOH prepared by the sol-gel method. The catalyst precursor was fired at 450 Degree-Sign C, ground and sifted through different meshes. Two powders were obtained with different particle sizes: sample A (50-75 {mu}m) and sample B (smaller than 50 {mu}m). These powders are composed of iron oxide particles widely dispersed in the non-crystalline matrix of aluminum oxide and they are not ferromagnetic. After reduction process the powders are composed of {alpha}-Fe nanoparticles inside hercynite matrix. These nanofillers are composed of hercynite containing {alpha}-Fe nanoparticles and MWCNT. The binary magnetic nanofillers were slightly ferromagnetic. The saturation magnetization of the nanofillers depended on the powder particle size. The nanofiller obtained from powder particles in the range 50-75 {mu}m showed a saturation magnetization 36% higher than the one formed from powder particles smaller than 50 {mu}m. The phenomenon is explained in terms of changes in the magnetic environment of the particles as consequence of the presence of MWCNT.

  16. Methods for Mediation Analysis with Missing Data

    Science.gov (United States)

    Zhang, Zhiyong; Wang, Lijuan

    2013-01-01

    Despite wide applications of both mediation models and missing data techniques, formal discussion of mediation analysis with missing data is still rare. We introduce and compare four approaches to dealing with missing data in mediation analysis including list wise deletion, pairwise deletion, multiple imputation (MI), and a two-stage maximum…

  17. Influence of binary mask estimation errors on robust speaker identification

    DEFF Research Database (Denmark)

    May, Tobias

    2017-01-01

    Missing-data strategies have been developed to improve the noise-robustness of automatic speech recognition systems in adverse acoustic conditions. This is achieved by classifying time-frequency (T-F) units into reliable and unreliable components, as indicated by a so-called binary mask. Different...... approaches have been proposed to handle unreliable feature components, each with distinct advantages. The direct masking (DM) approach attenuates unreliable T-F units in the spectral domain, which allows the extraction of conventionally used mel-frequency cepstral coefficients (MFCCs). Instead of attenuating....... Since each of these approaches utilizes the knowledge about reliable and unreliable feature components in a different way, they will respond differently to estimation errors in the binary mask. The goal of this study was to identify the most effective strategy to exploit knowledge about reliable...

  18. Application of pattern mixture models to address missing data in longitudinal data analysis using SPSS.

    Science.gov (United States)

    Son, Heesook; Friedmann, Erika; Thomas, Sue A

    2012-01-01

    Longitudinal studies are used in nursing research to examine changes over time in health indicators. Traditional approaches to longitudinal analysis of means, such as analysis of variance with repeated measures, are limited to analyzing complete cases. This limitation can lead to biased results due to withdrawal or data omission bias or to imputation of missing data, which can lead to bias toward the null if data are not missing completely at random. Pattern mixture models are useful to evaluate the informativeness of missing data and to adjust linear mixed model (LMM) analyses if missing data are informative. The aim of this study was to provide an example of statistical procedures for applying a pattern mixture model to evaluate the informativeness of missing data and conduct analyses of data with informative missingness in longitudinal studies using SPSS. The data set from the Patients' and Families' Psychological Response to Home Automated External Defibrillator Trial was used as an example to examine informativeness of missing data with pattern mixture models and to use a missing data pattern in analysis of longitudinal data. Prevention of withdrawal bias, omitted data bias, and bias toward the null in longitudinal LMMs requires the assessment of the informativeness of the occurrence of missing data. Missing data patterns can be incorporated as fixed effects into LMMs to evaluate the contribution of the presence of informative missingness to and control for the effects of missingness on outcomes. Pattern mixture models are a useful method to address the presence and effect of informative missingness in longitudinal studies.

  19. Cyclists’ Anger As Determinant of Near Misses Involving Different Road Users

    Directory of Open Access Journals (Sweden)

    Víctor Marín Puchades

    2017-12-01

    Full Text Available Road anger constitutes one of the determinant factors related to safety outcomes (e.g., accidents, near misses. Although cyclists are considered vulnerable road users due to their relatively high rate of fatalities in traffic, previous research has solely focused on car drivers, and no study has yet investigated the effect of anger on cyclists’ safety outcomes. The present research aims to investigate, for the first time, the effects of cycling anger toward different types of road users on near misses involving such road users and near misses in general. Using a daily diary web-based questionnaire, we collected data about daily trips, bicycle use, near misses experienced, cyclist’s anger and demographic information from 254 Spanish cyclists. Poisson regression was used to assess the association of cycling anger with near misses, which is a count variable. No relationship was found between general cycling anger and near misses occurrence. Anger toward specific road users had different effects on the probability of near misses with different road users. Anger toward the interaction with car drivers increased the probability of near misses involving cyclists and pedestrians. Anger toward interaction with pedestrians was associated with higher probability of near misses with pedestrians. Anger toward cyclists exerted no effect on the probability of near misses with any road user (i.e., car drivers, cyclists or pedestrians, whereas anger toward the interactions with the police had a diminishing effect on the occurrence of near misses’ involving all types of road users. The present study demonstrated that the effect of road anger on safety outcomes among cyclists is different from that of motorists. Moreover, the target of anger played an important role on safety both for the cyclist and the specific road users. Possible explanations for these differences are based on the difference in status and power with motorists, as well as on the potential

  20. Evaluating Failures and near Misses in Human Spaceflight History for Lessons for Future Human Spaceflight

    Science.gov (United States)

    Barr, Stephanie

    2010-01-01

    Studies done in the past have drawn on lessons learned with regard to human loss-of-life events. However, an examination of near-fatal accidents can be equally useful, not only in detecting causes, both proximate and systemic, but also for determining what factors averted disaster, what design decisions and/or operator actions prevented catastrophe. Binary pass/fail launch history is often used for risk, but this also has limitations. A program with a number of near misses can look more reliable than a consistently healthy program with a single out-of-family failure. Augmenting reliability evaluations with this near miss data can provide insight and expand on the limitations of a strictly pass/fail evaluation. This paper intends to show how near-miss lessons learned can provide crucial data for any new human spaceflight programs that are interested in sending man into space

  1. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Matthew J. Benacquista

    2013-03-01

    Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  2. Spectral properties of binary asteroids

    Science.gov (United States)

    Pajuelo, Myriam; Birlan, Mirel; Carry, Benoît; DeMeo, Francesca E.; Binzel, Richard P.; Berthier, Jérôme

    2018-04-01

    We present the first attempt to characterize the distribution of taxonomic class among the population of binary asteroids (15% of all small asteroids). For that, an analysis of 0.8-2.5{μ m} near-infrared spectra obtained with the SpeX instrument on the NASA/IRTF is presented. Taxonomic class and meteorite analog is determined for each target, increasing the sample of binary asteroids with known taxonomy by 21%. Most binary systems are bound in the S-, X-, and C- classes, followed by Q and V-types. The rate of binary systems in each taxonomic class agrees within uncertainty with the background population of small near-Earth objects and inner main belt asteroids, but for the C-types which are under-represented among binaries.

  3. Planets in Binary Star Systems

    CERN Document Server

    Haghighipour, Nader

    2010-01-01

    The discovery of extrasolar planets over the past decade has had major impacts on our understanding of the formation and dynamical evolution of planetary systems. There are features and characteristics unseen in our solar system and unexplainable by the current theories of planet formation and dynamics. Among these new surprises is the discovery of planets in binary and multiple-star systems. The discovery of such "binary-planetary" systems has confronted astrodynamicists with many new challenges, and has led them to re-examine the theories of planet formation and dynamics. Among these challenges are: How are planets formed in binary star systems? What would be the notion of habitability in such systems? Under what conditions can binary star systems have habitable planets? How will volatiles necessary for life appear on such planets? This volume seeks to gather the current research in the area of planets in binary and multistar systems and to familiarize readers with its associated theoretical and observation...

  4. RS CVn binary systems

    International Nuclear Information System (INIS)

    Linsky, J.L.

    1984-01-01

    The author attempts to place in context the vast amount of data obtained in the last few years as a result of X-ray, ultraviolet, optical, and microwave observations of RS CVn and similar spectroscopic binary systems. He concentrates on the RS CVn systems and their long-period analogs, and restricts the scope by attempting to answer on the basis of the recent data and theory following questions: (1) Are the original defining characteristics still valid and still adequate? (2) What is the evidence for discrete active regions? (3) Have we derived any meaningful physical properties for the atmospheres of RS CVn systems? (4) What are the flare observations telling us about magnetic fields in the RS CVn systems? (5) Is there evidence for systematic trends in RS CVn systems with spectral type?

  5. Cognitive distortions and gambling near-misses in Internet Gaming Disorder: A preliminary study.

    Directory of Open Access Journals (Sweden)

    Yin Wu

    Full Text Available Increased cognitive distortions (i.e. biased processing of chance, probability and skill are a key psychopathological process in disordered gambling. The present study investigated state and trait aspects of cognitive distortions in 22 individuals with Internet Gaming Disorder (IGD and 22 healthy controls. Participants completed the Gambling Related Cognitions Scale as a trait measure of cognitive distortions, and played a slot machine task delivering wins, near-misses and full-misses. Ratings of pleasure ("liking" and motivation to play ("wanting" were taken following the different outcomes, and gambling persistence was measured after a mandatory phase. IGD was associated with elevated trait cognitive distortions, in particular skill-oriented cognitions. On the slot machine task, the IGD group showed increased "wanting" ratings compared with control participants, while the two groups did not differ regarding their "liking" of the game. The IGD group displayed increased persistence on the slot machine task. Near-miss outcomes did not elicit stronger motivation to play compared to full-miss outcomes overall, and there was no group difference on this measure. However, a near-miss position effect was observed, such that near-misses stopping before the payline were rated as more motivating than near-misses that stopped after the payline, and this differentiation was attenuated in the IGD group, suggesting possible counterfactual thinking deficits in this group. These data provide preliminary evidence for increased incentive motivation and cognitive distortions in IGD, at least in the context of a chance-based gambling environment.

  6. Cognitive distortions and gambling near-misses in Internet Gaming Disorder: A preliminary study.

    Science.gov (United States)

    Wu, Yin; Sescousse, Guillaume; Yu, Hongbo; Clark, Luke; Li, Hong

    2018-01-01

    Increased cognitive distortions (i.e. biased processing of chance, probability and skill) are a key psychopathological process in disordered gambling. The present study investigated state and trait aspects of cognitive distortions in 22 individuals with Internet Gaming Disorder (IGD) and 22 healthy controls. Participants completed the Gambling Related Cognitions Scale as a trait measure of cognitive distortions, and played a slot machine task delivering wins, near-misses and full-misses. Ratings of pleasure ("liking") and motivation to play ("wanting") were taken following the different outcomes, and gambling persistence was measured after a mandatory phase. IGD was associated with elevated trait cognitive distortions, in particular skill-oriented cognitions. On the slot machine task, the IGD group showed increased "wanting" ratings compared with control participants, while the two groups did not differ regarding their "liking" of the game. The IGD group displayed increased persistence on the slot machine task. Near-miss outcomes did not elicit stronger motivation to play compared to full-miss outcomes overall, and there was no group difference on this measure. However, a near-miss position effect was observed, such that near-misses stopping before the payline were rated as more motivating than near-misses that stopped after the payline, and this differentiation was attenuated in the IGD group, suggesting possible counterfactual thinking deficits in this group. These data provide preliminary evidence for increased incentive motivation and cognitive distortions in IGD, at least in the context of a chance-based gambling environment.

  7. Analyzing time-ordered event data with missed observations.

    Science.gov (United States)

    Dokter, Adriaan M; van Loon, E Emiel; Fokkema, Wimke; Lameris, Thomas K; Nolet, Bart A; van der Jeugd, Henk P

    2017-09-01

    A common problem with observational datasets is that not all events of interest may be detected. For example, observing animals in the wild can difficult when animals move, hide, or cannot be closely approached. We consider time series of events recorded in conditions where events are occasionally missed by observers or observational devices. These time series are not restricted to behavioral protocols, but can be any cyclic or recurring process where discrete outcomes are observed. Undetected events cause biased inferences on the process of interest, and statistical analyses are needed that can identify and correct the compromised detection processes. Missed observations in time series lead to observed time intervals between events at multiples of the true inter-event time, which conveys information on their detection probability. We derive the theoretical probability density function for observed intervals between events that includes a probability of missed detection. Methodology and software tools are provided for analysis of event data with potential observation bias and its removal. The methodology was applied to simulation data and a case study of defecation rate estimation in geese, which is commonly used to estimate their digestive throughput and energetic uptake, or to calculate goose usage of a feeding site from dropping density. Simulations indicate that at a moderate chance to miss arrival events ( p  = 0.3), uncorrected arrival intervals were biased upward by up to a factor 3, while parameter values corrected for missed observations were within 1% of their true simulated value. A field case study shows that not accounting for missed observations leads to substantial underestimates of the true defecation rate in geese, and spurious rate differences between sites, which are introduced by differences in observational conditions. These results show that the derived methodology can be used to effectively remove observational biases in time-ordered event

  8. Planetary Formation and Dynamics in Binary Systems

    Science.gov (United States)

    Xie, J. W.

    2013-01-01

    explanation for the turnover point in the size distribution of the present-day asteroid belt. For the specific case of close binaries such as Alpha Centauri, the snowball growth mode provides a safe way for the bodies to grow through the problematic range with a size of 1˜50 km. In chapter 6, we investigate the intermediate stages of the planet formation in highly inclined cases. We find that the gas drag plays a crucial role in the evolution of the planetesimals' semi-major axis, and the results can be generally divided into two categories, i.e., the Kozai-on regime and the Kozai-off regime. For both regimes, a robust outcome over a wide range of parameters is that, the planetesimals migrate/jump inwards and pile up, leading to a severely truncated and dense planetesimal disk around the primary. In this compact and dense disk, the collision rates are high but the relative velocities are low, providing conditions which are favorable for the planetesimal growth, and potentially allow for the subsequent formation of planets. Finally, we summarize this thesis in chapter 7. Many open questions still remain in current research field of planet formation in binary systems, and the current Kepler project provides an unprecedented opportunity for such researches. A comprehensive understanding of planets in binaries requires placing them in a bigger context to include the formation and evolution of stars and/or clusters.

  9. Results of Database Studies in Spine Surgery Can Be Influenced by Missing Data.

    Science.gov (United States)

    Basques, Bryce A; McLynn, Ryan P; Fice, Michael P; Samuel, Andre M; Lukasiewicz, Adam M; Bohl, Daniel D; Ahn, Junyoung; Singh, Kern; Grauer, Jonathan N

    2017-12-01

    National databases are increasingly being used for research in spine surgery; however, one limitation of such databases that has received sparse mention is the frequency of missing data. Studies using these databases often do not emphasize the percentage of missing data for each variable used and do not specify how patients with missing data are incorporated into analyses. This study uses the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to examine whether different treatments of missing data can influence the results of spine studies. (1) What is the frequency of missing data fields for demographics, medical comorbidities, preoperative laboratory values, operating room times, and length of stay recorded in ACS-NSQIP? (2) Using three common approaches to handling missing data, how frequently do those approaches agree in terms of finding particular variables to be associated with adverse events? (3) Do different approaches to handling missing data influence the outcomes and effect sizes of an analysis testing for an association with these variables with occurrence of adverse events? Patients who underwent spine surgery between 2005 and 2013 were identified from the ACS-NSQIP database. A total of 88,471 patients undergoing spine surgery were identified. The most common procedures were anterior cervical discectomy and fusion, lumbar decompression, and lumbar fusion. Demographics, comorbidities, and perioperative laboratory values were tabulated for each patient, and the percent of missing data was noted for each variable. These variables were tested for an association with "any adverse event" using three separate multivariate regressions that used the most common treatments for missing data. In the first regression, patients with any missing data were excluded. In the second regression, missing data were treated as a negative or "reference" value; for continuous variables, the mean of each variable's reference range

  10. The 50 million missing women.

    Science.gov (United States)

    Allahbadia, Gautam N

    2002-09-01

    The epidemic of gender selection is ravaging countries like India & China. Approximately fifty million women are "missing" in the Indian population. Generally three principle causes are given: female infanticide, better food and health care for boys and maternal death at childbirth. Prenatal sex determination and the abortion of female fetuses threatens to skew the sex ratio to new highs. Estimates of the number of female fetuses being destroyed every year in India vary from two million to five million. This review from India attempts to summarize all the currently available methods of sex selection and also highlights the current medical practice regards the subject in south-east Asia.

  11. Measurement of Missing Tranverse Energy

    CERN Document Server

    The ATLAS Collaboration

    2009-01-01

    This note discusses the overall ATLAS detector performance for the reconstruction of the missing transverse energy, ETmiss. Two reconstruction algorithms are discussed and their performance is evaluated for a variety of simulated physics processes which probe different topologies and different total transverse energy regimes. In addition, effects of fake ETmiss, resulting from instrumental effects and from false reconstructions are investigated. Finally, studies with first data, corresponding to an integrated luminosity of 100 pb-1, are suggested which can be used to assess and calibrate the ETmiss performance at the startup of data taking.

  12. Bayes reconstruction of missing teeth

    DEFF Research Database (Denmark)

    Sporring, Jon; Jensen, Katrine Hommelhoff

    2008-01-01

    contains two major parts: A statistical model of a selection of tooth shapes and a reconstruction of missing data. We use a training set consisting of 3D scans of dental cast models obtained with a laser scanner, and we have build a model of the shape variability of the teeth, their neighbors...... or equivalently noise elimination and for data analysis. However for small sets of high dimensional data, the log-likelihood estimator for the covariance matrix is often far from convergence, and therefore reliable models must be obtained by use of prior information. We propose a natural and intrinsic...

  13. Windows 7 The Missing Manual

    CERN Document Server

    Pogue, David

    2010-01-01

    In early reviews, geeks raved about Windows 7. But if you're an ordinary mortal, learning what this new system is all about will be challenging. Fear not: David Pogue's Windows 7: The Missing Manual comes to the rescue. Like its predecessors, this book illuminates its subject with reader-friendly insight, plenty of wit, and hardnosed objectivity for beginners as well as veteran PC users. Windows 7 fixes many of Vista's most painful shortcomings. It's speedier, has fewer intrusive and nagging screens, and is more compatible with peripherals. Plus, Windows 7 introduces a slew of new features,

  14. Are there missing convective currents?

    International Nuclear Information System (INIS)

    Chen, C.Y.

    1992-01-01

    It is revealed in this letter that as far as distribution functions obtained from gyrokinetic equations are concerned, the standard formulae to evaluate currents in plasmas are not applicable due to the fact that those distribution functions are given in a moving coordinate frame and the moving is essentially related to perturbed fields. With heuristic and analytic approaches, appropriate formulae are obtained to evaluate several types of currents in plasmas of which some have been missing in previous approaches. (author). 6 refs, 1 fig

  15. What We’re Missing

    OpenAIRE

    Camille R. Whitney; Jing Liu

    2017-01-01

    For schools and teachers to help students develop knowledge and skills, students need to show up to class. Yet absenteeism is prevalent, especially in secondary schools. This study uses a rich data set tracking class attendance by day for over 50,000 middle and high school students from an urban district in academic years 2007–2008 through 2012–2013. Our results extend and modify the extant findings on absenteeism that have been based almost exclusively on full-day absenteeism, missing class-...

  16. Missing mass of the Universe

    International Nuclear Information System (INIS)

    Mazure, A.

    1989-01-01

    The first evidence for missing mass or dark matter comes from the 30's. On one hand, Oort noted that in the solar neighbourhood the mass of the stars (inferred from count numbers) cannot account for their observed velocities. On the other hand, observation on the sky of various galaxy condensations like the Coma cluster let suppose that they are actual bound systems and not only statistical fluctuations. However, with such an assumption, Zwicky concluded that the velocity dispersion of galaxies in Coma required 100 times more mass than contained in galaxies. Since this period, refined observations, analyses and a reevaluation of the cosmic distance scale reduced this factor but the problem is still present. It is particularly striking for spiral galaxies where systematic observations of rotation curves lead to infer the presence of spherical massive halos. These dynamical evidences form the first missing mass problem. The second one appears with the development of Great Unified Theories for which the natural laboratory is the very early Universe. A consequence of these theories is that our Universe could be closed by exotic particles which interact only gravitationally [fr

  17. Missing data reconstruction using Gaussian mixture models for fingerprint images

    Science.gov (United States)

    Agaian, Sos S.; Yeole, Rushikesh D.; Rao, Shishir P.; Mulawka, Marzena; Troy, Mike; Reinecke, Gary

    2016-05-01

    Publisher's Note: This paper, originally published on 25 May 2016, was replaced with a revised version on 16 June 2016. If you downloaded the original PDF, but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance. One of the most important areas in biometrics is matching partial fingerprints in fingerprint databases. Recently, significant progress has been made in designing fingerprint identification systems for missing fingerprint information. However, a dependable reconstruction of fingerprint images still remains challenging due to the complexity and the ill-posed nature of the problem. In this article, both binary and gray-level images are reconstructed. This paper also presents a new similarity score to evaluate the performance of the reconstructed binary image. The offered fingerprint image identification system can be automated and extended to numerous other security applications such as postmortem fingerprints, forensic science, investigations, artificial intelligence, robotics, all-access control, and financial security, as well as for the verification of firearm purchasers, driver license applicants, etc.

  18. Optimally cloned binary coherent states

    Science.gov (United States)

    Müller, C. R.; Leuchs, G.; Marquardt, Ch.; Andersen, U. L.

    2017-10-01

    Binary coherent state alphabets can be represented in a two-dimensional Hilbert space. We capitalize this formal connection between the otherwise distinct domains of qubits and continuous variable states to map binary phase-shift keyed coherent states onto the Bloch sphere and to derive their quantum-optimal clones. We analyze the Wigner function and the cumulants of the clones, and we conclude that optimal cloning of binary coherent states requires a nonlinearity above second order. We propose several practical and near-optimal cloning schemes and compare their cloning fidelity to the optimal cloner.

  19. The impact of 'missed care' on the professional socialisation of nursing students: A qualitative research study.

    Science.gov (United States)

    Gibbon, Bernard; Crane, Julie

    2018-04-07

    Missed care is a recently described concept that is subject to an increasing amount of international nursing research. The impact of missed care is associated with poorer patient outcomes (mortality and morbidity) and poorer levels of patient satisfaction with the services provided by the hospital. Missed care has also been linked to decreased staff satisfaction and increased intention to leave. Overall disaffection amongst registered nurses has also been reported. Professional socialisation refers to the acquisition of behaviours within cultural norms, and it has been suggested that students enter a period of professional socialisation during their programme. Whilst it has been proposed that students may absorb the characteristics of those around them, to date, no empirical studies have reported the impact of missed care on student nurses. The aim of this project is to explore the impact of missed care on the professional socialisation of student nurses. A qualitative study was undertaken in one higher education institute in UK with final year pre-registration nursing degree (adult field) students. Focus group interviews, utilizing a broad topic guide, were used to collect data which was analysed using thematic analysis. Student nurses were aware that some planned care is missed and these findings resonated with those identified in the literature. In addition to illuminating aspects of professional socialisation, analysis yielded five themes with regards to missed care: awareness, rationale, impact, strategies to avoid and influence of missed care on career aspiration. Student nurses exposed to missed care appear to accept this as part of their professional socialisation. With regards to professional socialisation, student nurses developed a pragmatic acceptance that care would be missed and that this could happen in any environment. As such they did not see missed care as influencing their career aspirations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Time Series Forecasting with Missing Values

    OpenAIRE

    Shin-Fu Wu; Chia-Yung Chang; Shie-Jue Lee

    2015-01-01

    Time series prediction has become more popular in various kinds of applications such as weather prediction, control engineering, financial analysis, industrial monitoring, etc. To deal with real-world problems, we are often faced with missing values in the data due to sensor malfunctions or human errors. Traditionally, the missing values are simply omitted or replaced by means of imputation methods. However, omitting those missing values may cause temporal discontinuity. Imputation methods, o...

  1. The Impact of the Nursing Practice Environment on Missed Nursing Care.

    Science.gov (United States)

    Hessels, Amanda J; Flynn, Linda; Cimiotti, Jeannie P; Cadmus, Edna; Gershon, Robyn R M

    2015-12-01

    Missed nursing care is an emerging problem negatively impacting patient outcomes. There are gaps in our knowledge of factors associated with missed nursing care. The aim of this study was to determine the relationship between the nursing practice environment and missed nursing care in acute care hospitals. This is a secondary analysis of cross sectional data from a survey of over 7.000 nurses from 70 hospitals on workplace and process of care. Ordinary least squares and multiple regression models were constructed to examine the relationship between the nursing practice environment and missed nursing care while controlling for characteristics of nurses and hospitals. Nurses missed delivering a significant amount of necessary patient care (10-27%). Inadequate staffing and inadequate resources were the practice environment factors most strongly associated with missed nursing care events. This multi-site study examined the risk and risk factors associated with missed nursing care. Improvements targeting modifiable risk factors may reduce the risk of missed nursing care.

  2. Separation in 5 Msun Binaries

    Science.gov (United States)

    Evans, Nancy R.; Bond, H. E.; Schaefer, G.; Mason, B. D.; Karovska, M.; Tingle, E.

    2013-01-01

    Cepheids (5 Msun stars) provide an excellent sample for determining the binary properties of fairly massive stars. International Ultraviolet Explorer (IUE) observations of Cepheids brighter than 8th magnitude resulted in a list of ALL companions more massive than 2.0 Msun uniformly sensitive to all separations. Hubble Space Telescope Wide Field Camera 3 (WFC3) has resolved three of these binaries (Eta Aql, S Nor, and V659 Cen). Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations for a sample of 18 Cepheids, and also a distribution of mass ratios. The distribution of orbital periods shows that the 5 Msun binaries prefer shorter periods than 1 Msun stars, reflecting differences in star formation processes.

  3. Mesoscopic model for binary fluids

    Science.gov (United States)

    Echeverria, C.; Tucci, K.; Alvarez-Llamoza, O.; Orozco-Guillén, E. E.; Morales, M.; Cosenza, M. G.

    2017-10-01

    We propose a model for studying binary fluids based on the mesoscopic molecular simulation technique known as multiparticle collision, where the space and state variables are continuous, and time is discrete. We include a repulsion rule to simulate segregation processes that does not require calculation of the interaction forces between particles, so binary fluids can be described on a mesoscopic scale. The model is conceptually simple and computationally efficient; it maintains Galilean invariance and conserves the mass and energy in the system at the micro- and macro-scale, whereas momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as the density profile, interface width, phase separation, and phase growth. We also apply the model to the study of binary fluids in crowded environments with consistent results.

  4. HTML5 The Missing Manual

    CERN Document Server

    MacDonald, Matthew

    2011-01-01

    HTML5 is more than a markup language-it's a dozen independent web standards all rolled into one. Until now, all it's been missing is a manual. With this thorough, jargon-free guide, you'll learn how to build web apps that include video tools, dynamic drawings, geolocation, offline web apps, drag-and-drop, and many other features. HTML5 is the future of the Web, and with this book you'll reach it quickly. The important stuff you need to know: Structure web pages in a new way. Learn how HTML5 helps make web design tools and search engines work smarter.Add audio and video without plugins. Build

  5. Integrative missing value estimation for microarray data.

    Science.gov (United States)

    Hu, Jianjun; Li, Haifeng; Waterman, Michael S; Zhou, Xianghong Jasmine

    2006-10-12

    Missing value estimation is an important preprocessing step in microarray analysis. Although several methods have been developed to solve this problem, their performance is unsatisfactory for datasets with high rates of missing data, high measurement noise, or limited numbers of samples. In fact, more than 80% of the time-series datasets in Stanford Microarray Database contain less than eight samples. We present the integrative Missing Value Estimation method (iMISS) by incorporating information from multiple reference microarray datasets to improve missing value estimation. For each gene with missing data, we derive a consistent neighbor-gene list by taking reference data sets into consideration. To determine whether the given reference data sets are sufficiently informative for integration, we use a submatrix imputation approach. Our experiments showed that iMISS can significantly and consistently improve the accuracy of the state-of-the-art Local Least Square (LLS) imputation algorithm by up to 15% improvement in our benchmark tests. We demonstrated that the order-statistics-based integrative imputation algorithms can achieve significant improvements over the state-of-the-art missing value estimation approaches such as LLS and is especially good for imputing microarray datasets with a limited number of samples, high rates of missing data, or very noisy measurements. With the rapid accumulation of microarray datasets, the performance of our approach can be further improved by incorporating larger and more appropriate reference datasets.

  6. Integrative missing value estimation for microarray data

    Directory of Open Access Journals (Sweden)

    Zhou Xianghong

    2006-10-01

    Full Text Available Abstract Background Missing value estimation is an important preprocessing step in microarray analysis. Although several methods have been developed to solve this problem, their performance is unsatisfactory for datasets with high rates of missing data, high measurement noise, or limited numbers of samples. In fact, more than 80% of the time-series datasets in Stanford Microarray Database contain less than eight samples. Results We present the integrative Missing Value Estimation method (iMISS by incorporating information from multiple reference microarray datasets to improve missing value estimation. For each gene with missing data, we derive a consistent neighbor-gene list by taking reference data sets into consideration. To determine whether the given reference data sets are sufficiently informative for integration, we use a submatrix imputation approach. Our experiments showed that iMISS can significantly and consistently improve the accuracy of the state-of-the-art Local Least Square (LLS imputation algorithm by up to 15% improvement in our benchmark tests. Conclusion We demonstrated that the order-statistics-based integrative imputation algorithms can achieve significant improvements over the state-of-the-art missing value estimation approaches such as LLS and is especially good for imputing microarray datasets with a limited number of samples, high rates of missing data, or very noisy measurements. With the rapid accumulation of microarray datasets, the performance of our approach can be further improved by incorporating larger and more appropriate reference datasets.

  7. Some properties of spectral binary stars

    International Nuclear Information System (INIS)

    Krajcheva, Z.T.; Popova, E.I.; Tutukov, A.V.; Yungel'son, L.R.; AN SSSR, Moscow. Astronomicheskij Sovet)

    1978-01-01

    Statistical investigations of spectra binary stars are carried out. Binary systems consisting of main sequence stars are considered. For 826 binary stars masses of components, ratios of component masses, semiaxes of orbits and orbital angular momenta are calculated. The distributions of these parameters and their correlations are analyzed. The dependences of statistical properties of spectral binary stars on their origin and evolution are discussed

  8. Missed injuries in the era of the trauma scan.

    Science.gov (United States)

    Lawson, Christy M; Daley, Brian J; Ormsby, Christine B; Enderson, Blaine

    2011-02-01

    A rapid computed tomography technique or "trauma scan" (TS) provides high-resolution studies of the head, cervical spine, chest, abdomen, and pelvis. We sought to determine whether TS has decreased missed injuries. A previous study of TS found a 3% missed rate. After institutional review board approval, trauma patients from January 2001 through December 2008 were reviewed for delayed diagnosis (DD) of injury to the head, cervical spine, chest, abdomen, or pelvis. Missed extremity injuries were excluded. Injury Severity Score, length of stay, type of injury, outcomes, and days to detection were captured. Of 26,264 patients reviewed, 90 patients had DD, with an incidence of 0.34%. DD most commonly presented on day 2. Injuries included 16 bowel/mesentery, 12 spine, 11 pelvic, 8 spleen, 6 diaphragm, 5 clavicle, 4 scapula, 4 cervical spine, 4 intracranial, 4 sternum, 3 maxillofacial, 3 liver, 2 heart/aorta, 2 vascular, 2 urethra/bladder, 2 pneumothorax, and 2 pancreas/common bile duct. DD resulted in 1 death, 6 prolonged intensive care unit stays, 19 operative interventions, and 38 additional interventions. TS is an effective way of evaluating trauma patients for intracranial, cervical spine, chest, abdomen, and pelvic injuries that have the potential to impact morbidity and mortality. The incidence of injuries missed in these crucial areas has been reduced at our institution by the use of this radiographic modality. The most common missed injury remains bowel, and so a high index of suspicion and the tertiary survey must remain a mainstay of therapy.

  9. Binary Systems and the Initial Mass Function

    Science.gov (United States)

    Malkov, O. Yu.

    2017-07-01

    In the present paper we discuss advantages and disadvantages of binary stars, which are important for star formation history determination. We show that to make definite conclusions of the initial mass function shape, it is necessary to study binary population well enough to correct the luminosity function for unresolved binaries; to construct the mass-luminosity relation based on wide binaries data, and to separate observational mass functions of primaries, of secondaries, and of unresolved binaries.

  10. Missing outcome data in a naturalistic psychodynamic group therapy study

    DEFF Research Database (Denmark)

    Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

    2017-01-01

    might have had a reliable improvement in GSI. The SPSS standard statistical imputations procedure estimated that 48.6% of the patients reliably improved in GSI, and 50.2% when therapist evaluations were not included. It is concluded that therapist evaluations are essential in order to avoid bias...

  11. Topology of black hole binary-single interactions

    Science.gov (United States)

    Samsing, Johan; Ilan, Teva

    2018-05-01

    We present a study on how the outcomes of binary-single interactions involving three black holes (BHs) distribute as a function of the initial conditions; a distribution we refer to as the topology. Using a N-body code that includes BH finite sizes and gravitational wave (GW) emission in the equation of motion (EOM), we perform more than a million binary-single interactions to explore the topology of both the Newtonian limit and the limit at which general relativistic (GR) effects start to become important. From these interactions, we are able to describe exactly under which conditions BH collisions and eccentric GW capture mergers form, as well as how GR in general modifies the Newtonian topology. This study is performed on both large- and microtopological scales. We further describe how the inclusion of GW emission in the EOM naturally leads to scenarios where the binary-single system undergoes two successive GW mergers.

  12. On the Counterfactual Nature of Gambling Near‐misses: An Experimental Study

    Science.gov (United States)

    van Dijk, Eric; Li, Hong; Aitken, Michael; Clark, Luke

    2017-01-01

    Abstract Research on gambling near‐misses has shown that objectively equivalent outcomes can yield divergent emotional and motivational responses. The subjective processing of gambling outcomes is affected substantially by close but non‐obtained outcomes (i.e. counterfactuals). In the current paper, we investigate how different types of near‐misses influence self‐perceived luck and subsequent betting behavior in a wheel‐of‐fortune task. We investigate the counterfactual mechanism of these effects by testing the relationship with a second task measuring regret/relief processing. Across two experiments (Experiment 1, n = 51; Experiment 2, n = 104), we demonstrate that near‐wins (neutral outcomes that are close to a jackpot) decreased self‐perceived luck, whereas near‐losses (neutral outcomes that are close to a major penalty) increased luck ratings. The effects of near‐misses varied by near‐miss position (i.e. whether the spinner stopped just short of, or passed through, the counterfactual outcome), consistent with established distinctions between upward versus downward, and additive versus subtractive, counterfactual thinking. In Experiment 1, individuals who showed stronger counterfactual processing on the regret/relief task were more responsive to near‐wins and near‐losses on the wheel‐of‐fortune task. The effect of near‐miss position was attenuated when the anticipatory phase (i.e. the spin and deceleration) was removed in Experiment 2. Further differences were observed within the objective gains and losses, between “clear” and “narrow” outcomes. Taken together, these results help substantiate the counterfactual mechanism of near‐misses. © 2017 The Authors Journal of Behavioral Decision Making Published by John Wiley & Sons Ltd. PMID:29081596

  13. A Review of Methods for Missing Data.

    Science.gov (United States)

    Pigott, Therese D.

    2001-01-01

    Reviews methods for handling missing data in a research study. Model-based methods, such as maximum likelihood using the EM algorithm and multiple imputation, hold more promise than ad hoc methods. Although model-based methods require more specialized computer programs and assumptions about the nature of missing data, these methods are appropriate…

  14. Methods for Handling Missing Secondary Respondent Data

    Science.gov (United States)

    Young, Rebekah; Johnson, David

    2013-01-01

    Secondary respondent data are underutilized because researchers avoid using these data in the presence of substantial missing data. The authors reviewed, evaluated, and tested solutions to this problem. Five strategies of dealing with missing partner data were reviewed: (a) complete case analysis, (b) inverse probability weighting, (c) correction…

  15. Student versus Faculty Perceptions of Missing Class.

    Science.gov (United States)

    Sleigh, Merry J.; Ritzer, Darren R.; Casey, Michael B.

    2002-01-01

    Examines and compares student and faculty attitudes towards students missing classes and class attendance. Surveys undergraduate students (n=231) in lower and upper level psychology courses and psychology faculty. Reports that students found more reasons acceptable for missing classes and that the amount of in-class material on the examinations…

  16. Methods to Minimize Zero-Missing Phenomenon

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2010-01-01

    With the increasing use of high-voltage AC cables at transmission levels, phenomena such as current zero-missing start to appear more often in transmission systems. Zero-missing phenomenon can occur when energizing cable lines with shunt reactors. This may considerably delay the opening of the ci...

  17. Cygnus X-3 and the problem of the missing Wolf-Rayet X-ray binaries

    NARCIS (Netherlands)

    Lommen, D.; Yungelson, L.; van den Heuvel, E.; Nelemans, G.A.; Portegies Zwart, S.

    2005-01-01

    Cygnus X-3 is a strong X-ray source (LX ≈ 1038 erg s-1) which is thought to consist of a compact object accreting matter from a helium star. We analytically find that the estimated ranges of mass-loss rate and orbital-period derivative for Cyg X-3 are consistent

  18. The missing binary tungsten iodide archetype cluster W{sub 4}I{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Stroebele, Markus; Meyer, H. Juergen [Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Universitaet Tuebingen (Germany)

    2016-12-15

    The tungsten iodide cluster W{sub 4}I{sub 10} is obtained by thermal conversion of W{sub 4}I{sub 13}. The crystal structure of W{sub 4}I{sub 10} was solved and refined by means of powder X-ray diffraction techniques. The structure is based on a tetrahedral tungsten cluster core, two face capping, five edge-bridging, and four apical iodido ligands of which two have bridging functionalities with adjacent clusters. Cluster chains in the structure are arranged following the motive of a kinked chain. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. The Fate of Neutron Star Binary Mergers

    Energy Technology Data Exchange (ETDEWEB)

    Piro, Anthony L. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Giacomazzo, Bruno [Physics Department, University of Trento, via Sommarive 14, I-38123 Trento (Italy); Perna, Rosalba, E-mail: piro@carnegiescience.edu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)

    2017-08-01

    Following merger, a neutron star (NS) binary can produce roughly one of three different outcomes: (1) a stable NS, (2) a black hole (BH), or (3) a supramassive, rotationally supported NS, which then collapses to a BH following angular momentum losses. Which of these fates occur and in what proportion has important implications for the electromagnetic transient associated with the mergers and the expected gravitational wave (GW) signatures, which in turn depend on the high density equation of state (EOS). Here we combine relativistic calculations of NS masses using realistic EOSs with Monte Carlo population synthesis based on the mass distribution of NS binaries in our Galaxy to predict the distribution of fates expected. For many EOSs, a significant fraction of the remnants are NSs or supramassive NSs. This lends support to scenarios in which a quickly spinning, highly magnetized NS may be powering an electromagnetic transient. This also indicates that it will be important for future GW observatories to focus on high frequencies to study the post-merger GW emission. Even in cases where individual GW events are too low in signal to noise to study the post merger signature in detail, the statistics of how many mergers produce NSs versus BHs can be compared with our work to constrain the EOS. To match short gamma-ray-burst (SGRB) X-ray afterglow statistics, we find that the stiffest EOSs are ruled out. Furthermore, many popular EOSs require a significant fraction of ∼60%–70% of SGRBs to be from NS–BH mergers rather than just binary NSs.

  20. Missed opportunities in child healthcare

    Directory of Open Access Journals (Sweden)

    Linda Jonker

    2014-08-01

    Objectives: This article describes the experiences of mothers that utilised comprehensive child health services in the Cape Metropolitan area of South Africa. Services included treatment for diseases; preventative interventions such as immunisation; and promotive interventions, such as improvement in nutrition and promotion of breastfeeding. Method: A qualitative, descriptive phenomenological approach was applied to explore the experiences and perceptions of mothers and/or carers utilising child healthcare services. Thirty percent of the clinics were selected purposively from the total population. A convenience purposive non-probability sampling method was applied to select 17 mothers who met the criteria and gave written consent. Interviews were conducted and recorded digitally using an interview guide. The data analysis was done using Tesch’s eight step model. Results: Findings of the study indicated varied experiences. Not all mothers received information about the Road to Health book or card. According to the mothers, integrated child healthcare services were not practised. The consequences were missed opportunities in immunisation, provision of vitamin A, absence of growth monitoring, feeding assessment and provision of nutritional advice. Conclusion: There is a need for simple interventions such as oral rehydration, early recognition and treatment of diseases, immunisation, growth monitoring and appropriate nutrition advice. These services were not offered diligently. Such interventions could contribute to reducing the incidence of child morbidity and mortality.

  1. Nurses' personal and ward accountability and missed nursing care: A cross-sectional study.

    Science.gov (United States)

    Srulovici, Einav; Drach-Zahavy, Anat

    2017-10-01

    lower missed nursing care, beyond scarce resources. Implementation of local and national education programs for nurses and managers, accompanied with empirical research, might increase personal and ward accountability, thereby decreasing missed nursing care. This might help to create a safety culture and reduce negative outcomes for patients, nurses, and organizations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Hidden slow pulsars in binaries

    Science.gov (United States)

    Tavani, Marco; Brookshaw, Leigh

    1993-01-01

    The recent discovery of the binary containing the slow pulsar PSR 1718-19 orbiting around a low-mass companion star adds new light on the characteristics of binary pulsars. The properties of the radio eclipses of PSR 1718-19 are the most striking observational characteristics of this system. The surface of the companion star produces a mass outflow which leaves only a small 'window' in orbital phase for the detection of PSR 1718-19 around 400 MHz. At this observing frequency, PSR 1718-19 is clearly observable only for about 1 hr out of the total 6.2 hr orbital period. The aim of this Letter is twofold: (1) to model the hydrodynamical behavior of the eclipsing material from the companion star of PSR 1718-19 and (2) to argue that a population of binary slow pulsars might have escaped detection in pulsar surveys carried out at 400 MHz. The possible existence of a population of partially or totally hidden slow pulsars in binaries will have a strong impact on current theories of binary evolution of neutron stars.

  3. The Young Visual Binary Survey

    Science.gov (United States)

    Prato, Lisa; Avilez, Ian; Lindstrom, Kyle; Graham, Sean; Sullivan, Kendall; Biddle, Lauren; Skiff, Brian; Nofi, Larissa; Schaefer, Gail; Simon, Michal

    2018-01-01

    Differences in the stellar and circumstellar properties of the components of young binaries provide key information about star and disk formation and evolution processes. Because objects with separations of a few to a few hundred astronomical units share a common environment and composition, multiple systems allow us to control for some of the factors which play into star formation. We are completing analysis of a rich sample of about 100 pre-main sequence binaries and higher order multiples, primarily located in the Taurus and Ophiuchus star forming regions. This poster will highlight some of out recent, exciting results. All reduced spectra and the results of our analysis will be publicly available to the community at http://jumar.lowell.edu/BinaryStars/. Support for this research was provided in part by NSF award AST-1313399 and by NASA Keck KPDA funding.

  4. ACOUSTIC EFFECTS ON BINARY AEROELASTICITY MODEL

    Directory of Open Access Journals (Sweden)

    Kok Hwa Yu

    2011-10-01

    Full Text Available Acoustics is the science concerned with the study of sound. The effects of sound on structures attract overwhelm interests and numerous studies were carried out in this particular area. Many of the preliminary investigations show that acoustic pressure produces significant influences on structures such as thin plate, membrane and also high-impedance medium like water (and other similar fluids. Thus, it is useful to investigate the structure response with the presence of acoustics on aircraft, especially on aircraft wings, tails and control surfaces which are vulnerable to flutter phenomena. The present paper describes the modeling of structural-acoustic interactions to simulate the external acoustic effect on binary flutter model. Here, the binary flutter model which illustrated as a rectangular wing is constructed using strip theory with simplified unsteady aerodynamics involving flap and pitch degree of freedom terms. The external acoustic excitation, on the other hand, is modeled using four-node quadrilateral isoparametric element via finite element approach. Both equations then carefully coupled and solved using eigenvalue solution. The mentioned approach is implemented in MATLAB and the outcome of the simulated result are later described, analyzed and illustrated in this paper.

  5. Clustering for Binary Data Sets by Using Genetic Algorithm-Incremental K-means

    Science.gov (United States)

    Saharan, S.; Baragona, R.; Nor, M. E.; Salleh, R. M.; Asrah, N. M.

    2018-04-01

    This research was initially driven by the lack of clustering algorithms that specifically focus in binary data. To overcome this gap in knowledge, a promising technique for analysing this type of data became the main subject in this research, namely Genetic Algorithms (GA). For the purpose of this research, GA was combined with the Incremental K-means (IKM) algorithm to cluster the binary data streams. In GAIKM, the objective function was based on a few sufficient statistics that may be easily and quickly calculated on binary numbers. The implementation of IKM will give an advantage in terms of fast convergence. The results show that GAIKM is an efficient and effective new clustering algorithm compared to the clustering algorithms and to the IKM itself. In conclusion, the GAIKM outperformed other clustering algorithms such as GCUK, IKM, Scalable K-means (SKM) and K-means clustering and paves the way for future research involving missing data and outliers.

  6. Missed opportunities in child healthcare

    Directory of Open Access Journals (Sweden)

    Linda Jonker

    2014-01-01

    Full Text Available Background: Various policies in health, such as Integrated Management of Childhood Illnesses, were introduced to enhance integrated service delivery in child healthcare. During clinical practice the researcher observed that integrated services may not be rendered.Objectives: This article describes the experiences of mothers that utilised comprehensive child health services in the Cape Metropolitan area of South Africa. Services included treatment for diseases; preventative interventions such as immunisation; and promotive interventions, such as improvement in nutrition and promotion of breastfeeding.Method: A qualitative, descriptive phenomenological approach was applied to explore the experiences and perceptions of mothers and/or carers utilising child healthcare services. Thirty percent of the clinics were selected purposively from the total population. A convenience purposive non-probability sampling method was applied to select 17 mothers who met the criteria and gave written consent. Interviews were conducted and recorded digitally using an interview guide. The data analysis was done using Tesch’s eight step model.Results: Findings of the study indicated varied experiences. Not all mothers received information about the Road to Health book or card. According to the mothers, integrated child healthcare services were not practised. The consequences were missed opportunities in immunisation, provision of vitamin A, absence of growth monitoring, feeding assessment and provision of nutritional advice.Conclusion: There is a need for simple interventions such as oral rehydration, early recognition and treatment of diseases, immunisation, growth monitoring and appropriate nutrition advice. These services were not offered diligently. Such interventions could contribute to reducing the incidence of child morbidity and mortality.

  7. Evolution in close binary systems

    International Nuclear Information System (INIS)

    Yungel'son, L.R.; Masevich, A.G.

    1983-01-01

    Duality is the property most typical of stars. If one investigates how prevalent double stars are, making due allowance for selection effects, one finds that as many as 90 percent of all stars are paired. Contrary to tradition it is single stars that are out of the ordinary, and as will be shown presently even some of these may have been formed by coalescence of the members of binary systems. This review deals with the evolution of close binaries, defined as double-star systems whose evolution entails exchange of material between the two components

  8. Creating Web Sites The Missing Manual

    CERN Document Server

    MacDonald, Matthew

    2006-01-01

    Think you have to be a technical wizard to build a great web site? Think again. For anyone who wants to create an engaging web site--for either personal or business purposes--Creating Web Sites: The Missing Manual demystifies the process and provides tools, techniques, and expert guidance for developing a professional and reliable web presence. Like every Missing Manual, you can count on Creating Web Sites: The Missing Manual to be entertaining and insightful and complete with all the vital information, clear-headed advice, and detailed instructions you need to master the task at hand. Autho

  9. Scalable Tensor Factorizations with Missing Data

    DEFF Research Database (Denmark)

    Acar, Evrim; Dunlavy, Daniel M.; Kolda, Tamara G.

    2010-01-01

    of missing data, many important data sets will be discarded or improperly analyzed. Therefore, we need a robust and scalable approach for factorizing multi-way arrays (i.e., tensors) in the presence of missing data. We focus on one of the most well-known tensor factorizations, CANDECOMP/PARAFAC (CP...... is shown to successfully factor tensors with noise and up to 70% missing data. Moreover, our approach is significantly faster than the leading alternative and scales to larger problems. To show the real-world usefulness of CP-WOPT, we illustrate its applicability on a novel EEG (electroencephalogram...

  10. Dual jets from binary black holes.

    Science.gov (United States)

    Palenzuela, Carlos; Lehner, Luis; Liebling, Steven L

    2010-08-20

    The coalescence of supermassive black holes--a natural outcome when galaxies merge--should produce gravitational waves and would likely be associated with energetic electromagnetic events. We have studied the coalescence of such binary black holes within an external magnetic field produced by the expected circumbinary disk surrounding them. Solving the Einstein equations to describe black holes interacting with surrounding plasma, we present numerical evidence for possible jets driven by these systems. Extending the process described by Blandford and Znajek for a single, spinning black hole, the picture that emerges suggests that the electromagnetic field extracts energy from the orbiting black holes, which ultimately merge and settle into the standard Blandford-Znajek scenario. Emissions along these jets could potentially be observable at large distances.

  11. Dealing with missing data in a multi-question depression scale: a comparison of imputation methods

    Directory of Open Access Journals (Sweden)

    Stuart Heather

    2006-12-01

    Full Text Available Abstract Background Missing data present a challenge to many research projects. The problem is often pronounced in studies utilizing self-report scales, and literature addressing different strategies for dealing with missing data in such circumstances is scarce. The objective of this study was to compare six different imputation techniques for dealing with missing data in the Zung Self-reported Depression scale (SDS. Methods 1580 participants from a surgical outcomes study completed the SDS. The SDS is a 20 question scale that respondents complete by circling a value of 1 to 4 for each question. The sum of the responses is calculated and respondents are classified as exhibiting depressive symptoms when their total score is over 40. Missing values were simulated by randomly selecting questions whose values were then deleted (a missing completely at random simulation. Additionally, a missing at random and missing not at random simulation were completed. Six imputation methods were then considered; 1 multiple imputation, 2 single regression, 3 individual mean, 4 overall mean, 5 participant's preceding response, and 6 random selection of a value from 1 to 4. For each method, the imputed mean SDS score and standard deviation were compared to the population statistics. The Spearman correlation coefficient, percent misclassified and the Kappa statistic were also calculated. Results When 10% of values are missing, all the imputation methods except random selection produce Kappa statistics greater than 0.80 indicating 'near perfect' agreement. MI produces the most valid imputed values with a high Kappa statistic (0.89, although both single regression and individual mean imputation also produced favorable results. As the percent of missing information increased to 30%, or when unbalanced missing data were introduced, MI maintained a high Kappa statistic. The individual mean and single regression method produced Kappas in the 'substantial agreement' range

  12. Backyard Telescopes Watch an Expanding Binary

    Science.gov (United States)

    Kohler, Susanna

    2018-01-01

    eclipsing binary system. Then the system must be observed regularly over a very long period of time.Though such a feat is challenging, a team of astronomers has done precisely this. The Center for Backyard Astrophysics (CBA) a group of primarily amateur astronomers located around the world has collectively observed the AM CVn star system ES Ceti using seven different telescopes over more than a decade. In total, they now have measurements of ES Cetis period spanning 20012017. Now, in a publication led by Enrique de Miguel (CBA-Huelva and University of Huelva, Spain), the group details the outcomes of their patience.Testing the ModelThis OC diagram of the timings of minimum light relative to a test ephemeris demonstrates that ES Cetis orbital period is steadily increasing over time. [de Miguel et al. 2017]De Miguel and collaborators find that ES Cetis 10.3-minute orbital period has indeed increased over time as predicted by the model at a relatively rapid rate: the timescale for change, described by P/(dP/dt), is 10 million years. This outcome is consistent with the hypothesis that the mass transfer and binary evolution of such systems is driven by gravitational radiation marking one of the first such demonstrations with a cataclysmic variable.Whats next for ES Ceti? Systems such as this one will make for interesting targets for the Laser Interferometer Space Antenna (LISA; planned for a 2034 launch). The gravitational radiation emitted by AM CVns like ES Ceti should be strong enough and in the right frequency range to be detected by LISA, providing another test of our models for how these star systems evolve.CitationEnrique de Miguel et al 2018 ApJ 852 19. doi:10.3847/1538-4357/aa9ed6

  13. The prevention and handling of the missing data

    OpenAIRE

    Kang, Hyun

    2013-01-01

    Even in a well-designed and controlled study, missing data occurs in almost all research. Missing data can reduce the statistical power of a study and can produce biased estimates, leading to invalid conclusions. This manuscript reviews the problems and types of missing data, along with the techniques for handling missing data. The mechanisms by which missing data occurs are illustrated, and the methods for handling the missing data are discussed. The paper concludes with recommendations for ...

  14. A prospective evaluation of missed injuries in trauma patients, before and after formalising the trauma tertiary survey.

    Science.gov (United States)

    Keijzers, Gerben B; Campbell, Don; Hooper, Jeffrey; Bost, Nerolie; Crilly, Julia; Steele, Michael Craig; Del Mar, Chris; Geeraedts, Leo M G

    2014-01-01

    This study prospectively evaluated in-hospital and postdischarge missed injury rates in admitted trauma patients, before and after the formalisation of a trauma tertiary survey (TTS) procedure. Prospective before-and-after cohort study. TTS were formalised in a single regional level II trauma hospital in November 2009. All multitrauma patients admitted between March-October 2009 (preformalisation of TTS) and December 2009-September 2010 (post-) were assessed for missed injury, classified into three types: Type I, in-hospital, (injury missed at initial assessment, detected within 24 h); Type II, in-hospital (detected in hospital after 24 h, missed at initial assessment and by TTS); Type III, postdischarge (detected after hospital discharge). Secondary outcome measures included TTS performance rates and functional outcomes at 1 and 6 months. A total of 487 trauma patients were included (pre-: n = 235; post-: n = 252). In-hospital missed injury rate (Types I and II combined) was similar for both groups (3.8 vs. 4.8 %, P = 0.61), as were postdischarge missed injury rates (Type III) at 1 month (13.7 vs. 11.5 %, P = 0.43), and 6 months (3.8 vs. 3.3 %, P = 0.84) after discharge. TTS performance was substantially higher in the post-group (27 vs. 42 %, P cumulative missed injury rates >15 %. Some of these injuries were clinically relevant. Although TTS performance was significantly improved by formalising the process (from 27 to 42 %), this did not decrease missed injury rates.

  15. The Binary Ties that Bind

    Science.gov (United States)

    Rose, Mike

    2008-01-01

    As any reader of "About Campus" knows, binary oppositions contribute to the definitions of institutional types--the trade school versus the liberal arts college, for example. They help define disciplines and subdisciplines and the status differentials among them: consider the difference in intellectual cachet as one moves from linguistics to…

  16. Optimally cloned binary coherent states

    DEFF Research Database (Denmark)

    Mueller, C. R.; Leuchs, G.; Marquardt, Ch

    2017-01-01

    their quantum-optimal clones. We analyze the Wigner function and the cumulants of the clones, and we conclude that optimal cloning of binary coherent states requires a nonlinearity above second order. We propose several practical and near-optimal cloning schemes and compare their cloning fidelity to the optimal...

  17. Subluminous X-ray binaries

    NARCIS (Netherlands)

    Armas Padilla, M.

    2013-01-01

    The discovery of the first X-ray binary, Scorpius X-1, by Giacconi et al. (1962), marked the birth of X-ray astronomy. Following that discovery, many additional X-ray sources where found with the first generation of X-ray rockets and observatories (e.g., UHURU and Einstein). The short-timescale

  18. Misclassification in binary choice models

    Czech Academy of Sciences Publication Activity Database

    Meyer, B. D.; Mittag, Nikolas

    2017-01-01

    Roč. 200, č. 2 (2017), s. 295-311 ISSN 0304-4076 R&D Projects: GA ČR(CZ) GJ16-07603Y Institutional support: Progres-Q24 Keywords : measurement error * binary choice models * program take-up Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 1.633, year: 2016

  19. Misclassification in binary choice models

    Czech Academy of Sciences Publication Activity Database

    Meyer, B. D.; Mittag, Nikolas

    2017-01-01

    Roč. 200, č. 2 (2017), s. 295-311 ISSN 0304-4076 Institutional support: RVO:67985998 Keywords : measurement error * binary choice models * program take-up Subject RIV: AH - Economics OBOR OECD: Economic Theory Impact factor: 1.633, year: 2016

  20. Binary logic is rich enough

    International Nuclear Information System (INIS)

    Zapatrin, R.R.

    1992-01-01

    Given a finite ortholattice L, the *-semigroup is explicitly built whose annihilator ortholattice is isomorphic to L. Thus, it is shown that any finite quantum logic is the additive part of a binary logic. Some areas of possible applications are outlined. 7 refs

  1. Maternal near-misses at a provincial hospital in Papua New Guinea: A prospective observational study.

    Science.gov (United States)

    Bolnga, John W; Morris, Marilyn; Totona, Catherine; Laman, Moses

    2017-12-01

    Maternal near-miss indices are World Health Organisation (WHO) recognised indicators that may improve our understanding of factors associated with maternal morbidity and mortality. In Papua New Guinea (PNG) where maternal mortality is among the highest in the world, only one study has documented near-miss indices in a tertiary-level hospital, but none from provincial hospitals where the majority of under-privileged women access healthcare services. To determine the near-miss ratio, maternal mortality index (MMI), and associated maternal indices for Modilon Hospital in Madang Province of PNG. All women attending Modilon Hospital who met the WHO maternal near-miss definition and/or a WHO-modified (PNG-specific) near-miss definition, were prospectively enrolled. There were 6019 live births during the audit period; 163 women presented with life-threatening conditions (153 near-misses and 10 maternal deaths). The maternal near-miss ratio was 25.4/1000 live births and the maternal mortality ratio (MMR) was 166/100 000 live births, with a maternal death to near-miss ratio of 1:15.3. The severe maternal outcome ratio was 27.1/1000 live births and the total mortality index was 6.8%. Higher proportions of near-miss women were aged ≥30 years, nulliparous, illiterate, from rural communities, lacked formal employment, referred from peripheral health facilities, unbooked, had history of still births and were anaemic. Sociodemographic factors such as women's rights, education level and status in society, in addition to appropriate health reforms with greater financial and political support are urgently needed to ensure underprivileged women in rural PNG have access to family planning, supervised deliveries and skilled emergency obstetric care. © 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  2. Intention-to-treat analyses and missing data approaches in pharmacotherapy trials for alcohol use disorders.

    Science.gov (United States)

    Del Re, A C; Maisel, Natalya C; Blodgett, Janet C; Finney, John W

    2013-11-12

    Intention to treat (ITT) is an analytic strategy for reducing potential bias in treatment effects arising from missing data in randomised controlled trials (RCTs). Currently, no universally accepted definition of ITT exists, although many researchers consider it to require either no attrition or a strategy to handle missing data. Using the reports of a large pool of RCTs, we examined discrepancies between the types of analyses that alcohol pharmacotherapy researchers stated they used versus those they actually used. We also examined the linkage between analytic strategy (ie, ITT or not) and how missing data on outcomes were handled (if at all), and whether data analytic and missing data strategies have changed over time. Descriptive statistics were generated for reported and actual data analytic strategy and for missing data strategy. In addition, generalised linear models determined changes over time in the use of ITT analyses and missing data strategies. 165 RCTs of pharmacotherapy for alcohol use disorders. Of the 165 studies, 74 reported using an ITT strategy. However, less than 40% of the studies actually conducted ITT according to the rigorous definition above. Whereas no change in the use of ITT analyses over time was found, censored (last follow-up completed) and imputed missing data strategies have increased over time, while analyses of data only for the sample actually followed have decreased. Discrepancies in reporting versus actually conducting ITT analyses were found in this body of RCTs. Lack of clarity regarding the missing data strategy used was common. Consensus on a definition of ITT is important for an adequate understanding of research findings. Clearer reporting standards for analyses and the handling of missing data in pharmacotherapy trials and other intervention studies are needed.

  3. Maternal death and near miss measurement

    African Journals Online (AJOL)

    ABEOLUGBENGAS

    2008-05-26

    May 26, 2008 ... Maternal health services need to be accountable more than ever ... of maternal death and near miss audit, surveillance and review is ..... (d) A fundamental principle of these ..... quality assurance in obstetrics in Nigeria - a.

  4. Clustering with Missing Values: No Imputation Required

    Science.gov (United States)

    Wagstaff, Kiri

    2004-01-01

    Clustering algorithms can identify groups in large data sets, such as star catalogs and hyperspectral images. In general, clustering methods cannot analyze items that have missing data values. Common solutions either fill in the missing values (imputation) or ignore the missing data (marginalization). Imputed values are treated as just as reliable as the truly observed data, but they are only as good as the assumptions used to create them. In contrast, we present a method for encoding partially observed features as a set of supplemental soft constraints and introduce the KSC algorithm, which incorporates constraints into the clustering process. In experiments on artificial data and data from the Sloan Digital Sky Survey, we show that soft constraints are an effective way to enable clustering with missing values.

  5. Missed medical appointment among hypertensive and diabetic ...

    African Journals Online (AJOL)

    Keywords: Missed medical appointments, Hypertensive, Diabetic outpatients, Medication adherence, ... 12 weeks, at 95 % confidence level and 5 % error margin, 300 hypertensive ... monthly income and health insurance status of respondents ...

  6. Missed Radiation Therapy and Cancer Recurrence

    Science.gov (United States)

    Patients who miss radiation therapy sessions during cancer treatment have an increased risk of their disease returning, even if they eventually complete their course of radiation treatment, according to a new study.

  7. Optimal Robust Self-Testing by Binary Nonlocal XOR Games

    OpenAIRE

    Miller, Carl A.; Shi, Yaoyun

    2013-01-01

    Self-testing a quantum apparatus means verifying the existence of a certain quantum state as well as the effect of the associated measuring devices based only on the statistics of the measurement outcomes. Robust (i.e., error-tolerant) self-testing quantum apparatuses are critical building blocks for quantum cryptographic protocols that rely on imperfect or untrusted devices. We devise a general scheme for proving optimal robust self-testing properties for tests based on nonlocal binary XOR g...

  8. Bioinspired Computational Approach to Missing Value Estimation

    Directory of Open Access Journals (Sweden)

    Israel Edem Agbehadji

    2018-01-01

    Full Text Available Missing data occurs when values of variables in a dataset are not stored. Estimating these missing values is a significant step during the data cleansing phase of a big data management approach. The reason of missing data may be due to nonresponse or omitted entries. If these missing data are not handled properly, this may create inaccurate results during data analysis. Although a traditional method such as maximum likelihood method extrapolates missing values, this paper proposes a bioinspired method based on the behavior of birds, specifically the Kestrel bird. This paper describes the behavior and characteristics of the Kestrel bird, a bioinspired approach, in modeling an algorithm to estimate missing values. The proposed algorithm (KSA was compared with WSAMP, Firefly, and BAT algorithm. The results were evaluated using the mean of absolute error (MAE. A statistical test (Wilcoxon signed-rank test and Friedman test was conducted to test the performance of the algorithms. The results of Wilcoxon test indicate that time does not have a significant effect on the performance, and the quality of estimation between the paired algorithms was significant; the results of Friedman test ranked KSA as the best evolutionary algorithm.

  9. Astronomy of binary and multiple stars

    International Nuclear Information System (INIS)

    Tokovinin, A.A.

    1984-01-01

    Various types of binary stars and methods for their observation are described in a popular form. Some models of formation and evolution of binary and multiple star systems are presented. It is concluded that formation of binary and multiple stars is a regular stage in the process of star production

  10. Coevolution of Binaries and Circumbinary Gaseous Disks

    Science.gov (United States)

    Fleming, David; Quinn, Thomas R.

    2018-04-01

    The recent discoveries of circumbinary planets by Kepler raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disk, and how the disk and binary interact. The central binary excites resonances in the surrounding protoplanetary disk that drive evolution in both the binary orbital elements and in the disk. To probe how these interactions impact both binary eccentricity and disk structure evolution, we ran N-body smooth particle hydrodynamics (SPH) simulations of gaseous protoplanetary disks surrounding binaries based on Kepler 38 for 10^4 binary orbital periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disk via a parametric instability and excite disk eccentricity growth. Eccentric binaries strongly couple to the disk causing eccentricity growth for both the disk and binary. Disks around sufficiently eccentric binaries strongly couple to the disk and develop an m = 1 spiral wave launched from the 1:3 eccentric outer Lindblad resonance (EOLR). This wave corresponds to an alignment of gas particle longitude of periastrons. We find that in all simulations, the binary semi-major axis decays due to dissipation from the viscous disk.

  11. Formation and evolution of compact binaries

    NARCIS (Netherlands)

    Sluijs, Marcel Vincent van der

    2006-01-01

    In this thesis we investigate the formation and evolution of compact binaries. Chapters 2 through 4 deal with the formation of luminous, ultra-compact X-ray binaries in globular clusters. We show that the proposed scenario of magnetic capture produces too few ultra-compact X-ray binaries to explain

  12. Binary Linear-Time Erasure Decoding for Non-Binary LDPC codes

    OpenAIRE

    Savin, Valentin

    2009-01-01

    In this paper, we first introduce the extended binary representation of non-binary codes, which corresponds to a covering graph of the bipartite graph associated with the non-binary code. Then we show that non-binary codewords correspond to binary codewords of the extended representation that further satisfy some simplex-constraint: that is, bits lying over the same symbol-node of the non-binary graph must form a codeword of a simplex code. Applied to the binary erasure channel, this descript...

  13. The use of continuous data versus binary data in MTC models: a case study in rheumatoid arthritis.

    Science.gov (United States)

    Schmitz, Susanne; Adams, Roisin; Walsh, Cathal

    2012-11-06

    Estimates of relative efficacy between alternative treatments are crucial for decision making in health care. When sufficient head to head evidence is not available Bayesian mixed treatment comparison models provide a powerful methodology to obtain such estimates. While models can be fit to a broad range of efficacy measures, this paper illustrates the advantages of using continuous outcome measures compared to binary outcome measures. Using a case study in rheumatoid arthritis a Bayesian mixed treatment comparison model is fit to estimate the relative efficacy of five anti-TNF agents currently licensed in Europe. The model is fit for the continuous HAQ improvement outcome measure and a binary version thereof as well as for the binary ACR response measure and the underlying continuous effect. Results are compared regarding their power to detect differences between treatments. Sixteen randomized controlled trials were included for the analysis. For both analyses, based on the HAQ improvement as well as based on the ACR response, differences between treatments detected by the binary outcome measures are subsets of the differences detected by the underlying continuous effects. The information lost when transforming continuous data into a binary response measure translates into a loss of power to detect differences between treatments in mixed treatment comparison models. Binary outcome measures are therefore less sensitive to change than continuous measures. Furthermore the choice of cut-off point to construct the binary measure also impacts the relative efficacy estimates.

  14. The use of continuous data versus binary data in MTC models: A case study in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Schmitz Susanne

    2012-11-01

    Full Text Available Abstract Background Estimates of relative efficacy between alternative treatments are crucial for decision making in health care. When sufficient head to head evidence is not available Bayesian mixed treatment comparison models provide a powerful methodology to obtain such estimates. While models can be fit to a broad range of efficacy measures, this paper illustrates the advantages of using continuous outcome measures compared to binary outcome measures. Methods Using a case study in rheumatoid arthritis a Bayesian mixed treatment comparison model is fit to estimate the relative efficacy of five anti-TNF agents currently licensed in Europe. The model is fit for the continuous HAQ improvement outcome measure and a binary version thereof as well as for the binary ACR response measure and the underlying continuous effect. Results are compared regarding their power to detect differences between treatments. Results Sixteen randomized controlled trials were included for the analysis. For both analyses, based on the HAQ improvement as well as based on the ACR response, differences between treatments detected by the binary outcome measures are subsets of the differences detected by the underlying continuous effects. Conclusions The information lost when transforming continuous data into a binary response measure translates into a loss of power to detect differences between treatments in mixed treatment comparison models. Binary outcome measures are therefore less sensitive to change than continuous measures. Furthermore the choice of cut-off point to construct the binary measure also impacts the relative efficacy estimates.

  15. Detecting Malicious Code by Binary File Checking

    Directory of Open Access Journals (Sweden)

    Marius POPA

    2014-01-01

    Full Text Available The object, library and executable code is stored in binary files. Functionality of a binary file is altered when its content or program source code is changed, causing undesired effects. A direct content change is possible when the intruder knows the structural information of the binary file. The paper describes the structural properties of the binary object files, how the content can be controlled by a possible intruder and what the ways to identify malicious code in such kind of files. Because the object files are inputs in linking processes, early detection of the malicious content is crucial to avoid infection of the binary executable files.

  16. Permutation Entropy for Random Binary Sequences

    Directory of Open Access Journals (Sweden)

    Lingfeng Liu

    2015-12-01

    Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.

  17. Flexible link functions in nonparametric binary regression with Gaussian process priors.

    Science.gov (United States)

    Li, Dan; Wang, Xia; Lin, Lizhen; Dey, Dipak K

    2016-09-01

    In many scientific fields, it is a common practice to collect a sequence of 0-1 binary responses from a subject across time, space, or a collection of covariates. Researchers are interested in finding out how the expected binary outcome is related to covariates, and aim at better prediction in the future 0-1 outcomes. Gaussian processes have been widely used to model nonlinear systems; in particular to model the latent structure in a binary regression model allowing nonlinear functional relationship between covariates and the expectation of binary outcomes. A critical issue in modeling binary response data is the appropriate choice of link functions. Commonly adopted link functions such as probit or logit links have fixed skewness and lack the flexibility to allow the data to determine the degree of the skewness. To address this limitation, we propose a flexible binary regression model which combines a generalized extreme value link function with a Gaussian process prior on the latent structure. Bayesian computation is employed in model estimation. Posterior consistency of the resulting posterior distribution is demonstrated. The flexibility and gains of the proposed model are illustrated through detailed simulation studies and two real data examples. Empirical results show that the proposed model outperforms a set of alternative models, which only have either a Gaussian process prior on the latent regression function or a Dirichlet prior on the link function. © 2015, The International Biometric Society.

  18. Missing-Values Adjustment for Mixed-Type Data

    Directory of Open Access Journals (Sweden)

    Agostino Tarsitano

    2011-01-01

    data sets involving a mixture of numeric, ordinal, binary, and categorical variables. Our technique is a variation of the popular nearest neighbor hot deck imputation (NNHDI where “nearest” is defined in terms of a global distance obtained as a convex combination of the distance matrices computed for the various types of variables. We address the problem of proper weighting of the partial distance matrices in order to reflect their significance, reliability, and statistical adequacy. Performance of several weighting schemes is compared under a variety of settings in coordination with imputation of the least power mean of the Box-Cox transformation applied to the values of the donors. Through analysis of simulated and actual data sets, we will show that this approach is appropriate. Our main contribution has been to demonstrate that mixed data may optimally be combined to allow the accurate reconstruction of missing values in the target variable even when some data are absent from the other fields of the record.

  19. A ROSAT Survey of Contact Binary Stars

    Science.gov (United States)

    Geske, M. T.; Gettel, S. J.; McKay, T. A.

    2006-01-01

    Contact binary stars are common variable stars that are all believed to emit relatively large fluxes of X-rays. In this work we combine a large new sample of contact binary stars derived from the ROTSE-I telescope with X-ray data from the ROSAT All Sky Survey (RASS) to estimate the X-ray volume emissivity of contact binary stars in the Galaxy. We obtained X-ray fluxes for 140 contact binaries from the RASS, as well as two additional stars observed by the XMM-Newton observatory. From these data we confirm the emission of X-rays from all contact binary systems, with typical luminosities of approximately 1.0×1030 ergs s-1. Combining calculated luminosities with an estimated contact binary space density, we find that contact binaries do not have strong enough X-ray emission to account for a significant portion of the Galactic X-ray background.

  20. Near miss and minor occupational injury: Does it share a common causal pathway with major injury?

    Science.gov (United States)

    Alamgir, Hasanat; Yu, Shicheng; Gorman, Erin; Ngan, Karen; Guzman, Jaime

    2009-01-01

    An essential assumption of injury prevention programs is the common cause hypothesis that the causal pathways of near misses and minor injuries are similar to those of major injuries. The rates of near miss, minor injury and major injury of all reported incidents and musculoskeletal incidents (MSIs) were calculated for three health regions using information from a surveillance database and productive hours from payroll data. The relative distribution of individual causes and activities involved in near miss, minor injury and major injury were then compared. For all reported incidents, there were significant differences in the relative distribution of causes for near miss, minor, and major injury. However, the relative distribution of causes and activities involved in minor and major MSIs were similar. The top causes and activities involved were the same across near miss, minor, and major injury. Finding from this study support the use of near miss and minor injury data as potential outcome measures for injury prevention programs. (c) 2008 Wiley-Liss, Inc.

  1. Striatal connectivity changes following gambling wins and near-misses: Associations with gambling severity

    NARCIS (Netherlands)

    Holst, R.J. van; Chase, H.W.; Clark, L.

    2014-01-01

    Frontostriatal circuitry is implicated in the cognitive distortions associated with gambling behaviour. 'Near-miss' events, where unsuccessful outcomes are proximal to a jackpot win, recruit overlapping neural circuitry with actual monetary wins. Personal control over a gamble (e.g., via choice) is

  2. Neurobehavioral Evidence for the "Near-Miss" Effect in Pathological Gamblers

    Science.gov (United States)

    Habib, Reza; Dixon, Mark R.

    2010-01-01

    The purpose of this translational study was twofold: (1) to contrast behavioral and brain activity between pathological and nonpathological gamblers, and (2) to examine differences as a function of the outcome of the spin of a slot machine, focusing predominately on the "Near-Miss"--when two reels stop on the same symbol, and that symbol…

  3. MISSE PEACE Polymers Atomic Oxygen Erosion Results

    Science.gov (United States)

    deGroh, Kim, K.; Banks, Bruce A.; McCarthy, Catherine E.; Rucker, Rochelle N.; Roberts, Lily M.; Berger, Lauren A.

    2006-01-01

    Forty-one different polymer samples, collectively called the Polymer Erosion and Contamination Experiment (PEACE) Polymers, have been exposed to the low Earth orbit (LEO) environment on the exterior of the International Space Station (ISS) for nearly 4 years as part of Materials International Space Station Experiment 2 (MISSE 2). The objective of the PEACE Polymers experiment was to determine the atomic oxygen erosion yield of a wide variety of polymeric materials after long term exposure to the space environment. The polymers range from those commonly used for spacecraft applications, such as Teflon (DuPont) FEP, to more recently developed polymers, such as high temperature polyimide PMR (polymerization of monomer reactants). Additional polymers were included to explore erosion yield dependence upon chemical composition. The MISSE PEACE Polymers experiment was flown in MISSE Passive Experiment Carrier 2 (PEC 2), tray 1, on the exterior of the ISS Quest Airlock and was exposed to atomic oxygen along with solar and charged particle radiation. MISSE 2 was successfully retrieved during a space walk on July 30, 2005, during Discovery s STS-114 Return to Flight mission. Details on the specific polymers flown, flight sample fabrication, pre-flight and post-flight characterization techniques, and atomic oxygen fluence calculations are discussed along with a summary of the atomic oxygen erosion yield results. The MISSE 2 PEACE Polymers experiment is unique because it has the widest variety of polymers flown in LEO for a long duration and provides extremely valuable erosion yield data for spacecraft design purposes.

  4. Breast carcinomas: why are they missed?

    Science.gov (United States)

    Muttarak, M; Pojchamarnwiputh, S; Chaiwun, B

    2006-10-01

    Mammography has proven to be an effective modality for the detection of early breast carcinoma. However, 4-34 percent of breast cancers may be missed at mammography. Delayed diagnosis of breast carcinoma results in an unfavourable prognosis. The objective of this study was to determine the causes and characteristics of breast carcinomas missed by mammography at our institution, with the aim of reducing the rate of missed carcinoma. We reviewed the reports of 13,191 mammograms performed over a five-year period. Breast Imaging Reporting and Data Systems (BI-RADS) were used for the mammographical assessment, and reports were cross-referenced with the histological diagnosis of breast carcinoma. Causes of missed carcinomas were classified. Of 344 patients who had breast carcinoma and had mammograms done prior to surgery, 18 (5.2 percent) failed to be diagnosed by mammography. Of these, five were caused by dense breast parenchyma obscuring the lesions, 11 were due to perception and interpretation errors, and one each from unusual lesion characteristics and poor positioning. Several factors, including dense breast parenchyma obscuring a lesion, perception error, interpretation error, unusual lesion characteristics, and poor technique or positioning, are possible causes of missed breast cancers.

  5. Substituting missing data in compositional analysis

    Energy Technology Data Exchange (ETDEWEB)

    Real, Carlos, E-mail: carlos.real@usc.es [Area de Ecologia, Departamento de Biologia Celular y Ecologia, Escuela Politecnica Superior, Universidad de Santiago de Compostela, 27002 Lugo (Spain); Angel Fernandez, J.; Aboal, Jesus R.; Carballeira, Alejo [Area de Ecologia, Departamento de Biologia Celular y Ecologia, Facultad de Biologia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2011-10-15

    Multivariate analysis of environmental data sets requires the absence of missing values or their substitution by small values. However, if the data is transformed logarithmically prior to the analysis, this solution cannot be applied because the logarithm of a small value might become an outlier. Several methods for substituting the missing values can be found in the literature although none of them guarantees that no distortion of the structure of the data set is produced. We propose a method for the assessment of these distortions which can be used for deciding whether to retain or not the samples or variables containing missing values and for the investigation of the performance of different substitution techniques. The method analyzes the structure of the distances among samples using Mantel tests. We present an application of the method to PCDD/F data measured in samples of terrestrial moss as part of a biomonitoring study. - Highlights: > Missing values in multivariate data sets must be substituted prior to analysis. > The substituted values can modify the structure of the data set. > We developed a method to estimate the magnitude of the alterations. > The method is simple and based on the Mantel test. > The method allowed the identification of problematic variables in a sample data set. - A method is presented for the assessment of the possible distortions in multivariate analysis caused by the substitution of missing values.

  6. Substituting missing data in compositional analysis

    International Nuclear Information System (INIS)

    Real, Carlos; Angel Fernandez, J.; Aboal, Jesus R.; Carballeira, Alejo

    2011-01-01

    Multivariate analysis of environmental data sets requires the absence of missing values or their substitution by small values. However, if the data is transformed logarithmically prior to the analysis, this solution cannot be applied because the logarithm of a small value might become an outlier. Several methods for substituting the missing values can be found in the literature although none of them guarantees that no distortion of the structure of the data set is produced. We propose a method for the assessment of these distortions which can be used for deciding whether to retain or not the samples or variables containing missing values and for the investigation of the performance of different substitution techniques. The method analyzes the structure of the distances among samples using Mantel tests. We present an application of the method to PCDD/F data measured in samples of terrestrial moss as part of a biomonitoring study. - Highlights: → Missing values in multivariate data sets must be substituted prior to analysis. → The substituted values can modify the structure of the data set. → We developed a method to estimate the magnitude of the alterations. → The method is simple and based on the Mantel test. → The method allowed the identification of problematic variables in a sample data set. - A method is presented for the assessment of the possible distortions in multivariate analysis caused by the substitution of missing values.

  7. Binary evolution and observational constraints

    International Nuclear Information System (INIS)

    Loore, C. de

    1984-01-01

    The evolution of close binaries is discussed in connection with problems concerning mass and angular momentum losses. Theoretical and observational evidence for outflow of matter, leaving the system during evolution is given: statistics on total masses and mass ratios, effects of the accretion of the mass gaining component, the presence of streams, disks, rings, circumstellar envelopes, period changes, abundance changes in the atmosphere. The effects of outflowing matter on the evolution is outlined, and estimates of the fraction of matter expelled by the loser, and leaving the system, are given. The various time scales involved with evolution and observation are compared. Examples of non conservative evolution are discussed. Problems related to contact phases, on mass and energy losses, in connection with entropy changes are briefly analysed. For advanced stages the disruption probabilities for supernova explosions are examined. A global picture is given for the evolution of massive close binaries, from ZAMS, through WR phases, X-ray phases, leading to runaway pulsars or to a binary pulsar and later to a millisecond pulsar. (Auth.)

  8. X rays from radio binaries

    International Nuclear Information System (INIS)

    Apparao, K.M.V.

    1977-01-01

    Reference is made to the radio binary systems CC Cas, AR Lac, β Per (Algol), β Lyr, b Per and Cyg X-1. It is stated that a thermal interpretation of the radiation from Algol requires a much larger x-ray flux than the observed value of 3.8 x 10 -11 erg/cm 2 /sec/keV in the 2 to 6 keV energy range. Observations of some non-thermal flares, together with the small size of the radio source in Algol, indicate that the radio emission is non-thermal in nature. The radio emission is interpreted as synchrotron radiation and it is suggested that the observed x-ray emission is due to inverse Compton scattering of the light of the primary star by the radio electrons. The x-ray emission from other radio binaries is also calculated using this model. The energy for the radio electrons can arise from annihilation of magnetic lines connecting the binary stars, twisted by the rotation of the stars. (U.K.)

  9. Causal inference with missing exposure information: Methods and applications to an obstetric study.

    Science.gov (United States)

    Zhang, Zhiwei; Liu, Wei; Zhang, Bo; Tang, Li; Zhang, Jun

    2016-10-01

    Causal inference in observational studies is frequently challenged by the occurrence of missing data, in addition to confounding. Motivated by the Consortium on Safe Labor, a large observational study of obstetric labor practice and birth outcomes, this article focuses on the problem of missing exposure information in a causal analysis of observational data. This problem can be approached from different angles (i.e. missing covariates and causal inference), and useful methods can be obtained by drawing upon the available techniques and insights in both areas. In this article, we describe and compare a collection of methods based on different modeling assumptions, under standard assumptions for missing data (i.e. missing-at-random and positivity) and for causal inference with complete data (i.e. no unmeasured confounding and another positivity assumption). These methods involve three models: one for treatment assignment, one for the dependence of outcome on treatment and covariates, and one for the missing data mechanism. In general, consistent estimation of causal quantities requires correct specification of at least two of the three models, although there may be some flexibility as to which two models need to be correct. Such flexibility is afforded by doubly robust estimators adapted from the missing covariates literature and the literature on causal inference with complete data, and by a newly developed triply robust estimator that is consistent if any two of the three models are correct. The methods are applied to the Consortium on Safe Labor data and compared in a simulation study mimicking the Consortium on Safe Labor. © The Author(s) 2013.

  10. Binary Paths to Type Ia Supernovae Explosions: the Highlights

    Science.gov (United States)

    Ferrario, Lilia

    2013-01-01

    This symposium was focused on the hunt for the progenitors of Type Ia supernovae (SNe Ia). Is there a main channel for the production of SNe Ia? If so, are these elusive progenitors single degenerate or double degenerate systems? Although most participants seemed to favor the single degenerate channel, there was no general agreement on the type of binary system at play. An observational puzzle that was highlighted was the apparent paucity of supersoft sources in our Galaxy and also in external galaxies. The single degenerate channel (and as it was pointed out, quite possibly also the double degenerate channel) requires the binary system to pass through a phase of steady nuclear burning. However, the observed number of supersoft sources falls short by a factor of up to 100 in explaining the estimated birth rates of SNe Ia. Thus, are these supersoft sources somehow hidden away and radiating at different wavelengths, or are we missing some important pieces of this puzzle that may lead to the elimination of a certain class of progenitor? Another unanswered question concerns the dependence of SNe Ia luminosities on the age of their host galaxy. Several hypotheses were put forward, but none was singled out as the most likely explanation. It is fair to say that at the end of the symposium the definitive answer to the vexed progenitor question remained well and truly wide open.

  11. The experimental search for new predicted binary-alloy structures

    Science.gov (United States)

    Erb, K. C.; Richey, Lauren; Lang, Candace; Campbell, Branton; Hart, Gus

    2010-10-01

    Predicting new ordered phases in metallic alloys is a productive line of inquiry because configurational ordering in an alloy can dramatically alter their useful material properties. One is able to infer the existence of an ordered phase in an alloy using first-principles calculated formation enthalpies.ootnotetextG. L. W. Hart, ``Where are Nature's missing structures?,'' Nature Materials 6 941-945 2007 Using this approach, we have been able to identify stable (i.e. lowest energy) orderings in a variety of binary metallic alloys. Many of these phases have been observed experimentally in the past, though others have not. In pursuit of several of the missing structures, we have characterized potential orderings in PtCd, PtPd and PtMo alloys using synchrotron x-ray powder diffraction and symmetry-analysis tools.ootnotetextB. J. Campbell, H. T. Stokes, D. E. Tanner, and D. M. Hatch, ``ISODISPLACE: a web-based tool for exploring structural distortions,'' J. Appl. Cryst. 39, 607-614 (2006)

  12. Missing data imputation: focusing on single imputation.

    Science.gov (United States)

    Zhang, Zhongheng

    2016-01-01

    Complete case analysis is widely used for handling missing data, and it is the default method in many statistical packages. However, this method may introduce bias and some useful information will be omitted from analysis. Therefore, many imputation methods are developed to make gap end. The present article focuses on single imputation. Imputations with mean, median and mode are simple but, like complete case analysis, can introduce bias on mean and deviation. Furthermore, they ignore relationship with other variables. Regression imputation can preserve relationship between missing values and other variables. There are many sophisticated methods exist to handle missing values in longitudinal data. This article focuses primarily on how to implement R code to perform single imputation, while avoiding complex mathematical calculations.

  13. Time Series Forecasting with Missing Values

    Directory of Open Access Journals (Sweden)

    Shin-Fu Wu

    2015-11-01

    Full Text Available Time series prediction has become more popular in various kinds of applications such as weather prediction, control engineering, financial analysis, industrial monitoring, etc. To deal with real-world problems, we are often faced with missing values in the data due to sensor malfunctions or human errors. Traditionally, the missing values are simply omitted or replaced by means of imputation methods. However, omitting those missing values may cause temporal discontinuity. Imputation methods, on the other hand, may alter the original time series. In this study, we propose a novel forecasting method based on least squares support vector machine (LSSVM. We employ the input patterns with the temporal information which is defined as local time index (LTI. Time series data as well as local time indexes are fed to LSSVM for doing forecasting without imputation. We compare the forecasting performance of our method with other imputation methods. Experimental results show that the proposed method is promising and is worth further investigations.

  14. Collateral missing value imputation: a new robust missing value estimation algorithm for microarray data.

    Science.gov (United States)

    Sehgal, Muhammad Shoaib B; Gondal, Iqbal; Dooley, Laurence S

    2005-05-15

    Microarray data are used in a range of application areas in biology, although often it contains considerable numbers of missing values. These missing values can significantly affect subsequent statistical analysis and machine learning algorithms so there is a strong motivation to estimate these values as accurately as possible before using these algorithms. While many imputation algorithms have been proposed, more robust techniques need to be developed so that further analysis of biological data can be accurately undertaken. In this paper, an innovative missing value imputation algorithm called collateral missing value estimation (CMVE) is presented which uses multiple covariance-based imputation matrices for the final prediction of missing values. The matrices are computed and optimized using least square regression and linear programming methods. The new CMVE algorithm has been compared with existing estimation techniques including Bayesian principal component analysis imputation (BPCA), least square impute (LSImpute) and K-nearest neighbour (KNN). All these methods were rigorously tested to estimate missing values in three separate non-time series (ovarian cancer based) and one time series (yeast sporulation) dataset. Each method was quantitatively analyzed using the normalized root mean square (NRMS) error measure, covering a wide range of randomly introduced missing value probabilities from 0.01 to 0.2. Experiments were also undertaken on the yeast dataset, which comprised 1.7% actual missing values, to test the hypothesis that CMVE performed better not only for randomly occurring but also for a real distribution of missing values. The results confirmed that CMVE consistently demonstrated superior and robust estimation capability of missing values compared with other methods for both series types of data, for the same order of computational complexity. A concise theoretical framework has also been formulated to validate the improved performance of the CMVE

  15. Near-misses are an opportunity to improve patient safety: adapting strategies of high reliability organizations to healthcare.

    Science.gov (United States)

    Van Spall, Harriette; Kassam, Alisha; Tollefson, Travis T

    2015-08-01

    Near-miss investigations in high reliability organizations (HROs) aim to mitigate risk and improve system safety. Healthcare settings have a higher rate of near-misses and subsequent adverse events than most high-risk industries, but near-misses are not systematically reported or analyzed. In this review, we will describe the strategies for near-miss analysis that have facilitated a culture of safety and continuous quality improvement in HROs. Near-miss analysis is routine and systematic in HROs such as aviation. Strategies implemented in aviation include the Commercial Aviation Safety Team, which undertakes systematic analyses of near-misses, so that findings can be incorporated into Standard Operating Procedures (SOPs). Other strategies resulting from incident analyses include Crew Resource Management (CRM) for enhanced communication, situational awareness training, adoption of checklists during operations, and built-in redundancy within systems. Health care organizations should consider near-misses as opportunities for quality improvement. The systematic reporting and analysis of near-misses, commonplace in HROs, can be adapted to health care settings to prevent adverse events and improve clinical outcomes.

  16. Comparison of results from different imputation techniques for missing data from an anti-obesity drug trial

    DEFF Research Database (Denmark)

    Jørgensen, Anders W.; Lundstrøm, Lars H; Wetterslev, Jørn

    2014-01-01

    BACKGROUND: In randomised trials of medical interventions, the most reliable analysis follows the intention-to-treat (ITT) principle. However, the ITT analysis requires that missing outcome data have to be imputed. Different imputation techniques may give different results and some may lead to bias...... of handling missing data in a 60-week placebo controlled anti-obesity drug trial on topiramate. METHODS: We compared an analysis of complete cases with datasets where missing body weight measurements had been replaced using three different imputation methods: LOCF, baseline carried forward (BOCF) and MI...

  17. GALAXY ROTATION AND RAPID SUPERMASSIVE BINARY COALESCENCE

    Energy Technology Data Exchange (ETDEWEB)

    Holley-Bockelmann, Kelly [Vanderbilt University, Nashville, TN (United States); Khan, Fazeel Mahmood, E-mail: k.holley@vanderbilt.edu [Institute of Space Technology (IST), Islamabad (Pakistan)

    2015-09-10

    Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy.

  18. GALAXY ROTATION AND RAPID SUPERMASSIVE BINARY COALESCENCE

    International Nuclear Information System (INIS)

    Holley-Bockelmann, Kelly; Khan, Fazeel Mahmood

    2015-01-01

    Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy

  19. A novel asynchronous access method with binary interfaces

    Directory of Open Access Journals (Sweden)

    Torres-Solis Jorge

    2008-10-01

    Full Text Available Abstract Background Traditionally synchronous access strategies require users to comply with one or more time constraints in order to communicate intent with a binary human-machine interface (e.g., mechanical, gestural or neural switches. Asynchronous access methods are preferable, but have not been used with binary interfaces in the control of devices that require more than two commands to be successfully operated. Methods We present the mathematical development and evaluation of a novel asynchronous access method that may be used to translate sporadic activations of binary interfaces into distinct outcomes for the control of devices requiring an arbitrary number of commands to be controlled. With this method, users are required to activate their interfaces only when the device under control behaves erroneously. Then, a recursive algorithm, incorporating contextual assumptions relevant to all possible outcomes, is used to obtain an informed estimate of user intention. We evaluate this method by simulating a control task requiring a series of target commands to be tracked by a model user. Results When compared to a random selection, the proposed asynchronous access method offers a significant reduction in the number of interface activations required from the user. Conclusion This novel access method offers a variety of advantages over traditionally synchronous access strategies and may be adapted to a wide variety of contexts, with primary relevance to applications involving direct object manipulation.

  20. Obstetric near-miss and maternal mortality in maternity university hospital, Damascus, Syria: a retrospective study.

    Science.gov (United States)

    Almerie, Yara; Almerie, Muhammad Q; Matar, Hosam E; Shahrour, Yasser; Al Chamat, Ahmad Abo; Abdulsalam, Asmaa

    2010-10-19

    Investigating severe maternal morbidity (near-miss) is a newly recognised tool that identifies women at highest risk of maternal death and helps allocate resources especially in low income countries. This study aims to i. document the frequency and nature of maternal near-miss at hospital level in Damascus, Capital of Syria, ii. evaluate the level of care at maternal life-saving emergency services by comparatively analysing near-misses and maternal mortalities. Retrospective facility-based review of cases of near-miss and maternal mortality that took place in the years 2006-2007 at Damascus Maternity University Hospital, Syria. Near-miss cases were defined based on disease-specific criteria (Filippi 2005) including: haemorrhage, hypertensive disorders in pregnancy, dystocia, infection and anaemia. Main outcomes included maternal mortality ratio (MMR), maternal near miss ratio (MNMR), mortality indices and proportion of near-miss cases and mortality cases to hospital admissions. There were 28,025 deliveries, 15 maternal deaths and 901 near-miss cases. The study showed a MNMR of 32.9/1000 live births, a MMR of 54.8/100,000 live births and a relatively low mortality index of 1.7%. Hypertensive disorders (52%) and haemorrhage (34%) were the top causes of near-misses. Late pregnancy haemorrhage was the leading cause of maternal mortality (60%) while sepsis had the highest mortality index (7.4%). Most cases (93%) were referred in critical conditions from other facilities; namely traditional birth attendants homes (67%), primary (5%) and secondary (10%) healthcare unites and private practices (11%). 26% of near-miss cases were admitted to Intensive Care Unit (ICU). Near-miss analyses provide valuable information on obstetric care. The study highlights the need to improve antenatal care which would help early identification of high risk pregnancies. It also emphasises the importance of both: developing protocols to prevent/manage post-partum haemorrhage and training health

  1. Obstetric near-miss and maternal mortality in maternity university hospital, Damascus, Syria: a retrospective study

    Directory of Open Access Journals (Sweden)

    Al Chamat Ahmad

    2010-10-01

    Full Text Available Abstract Background Investigating severe maternal morbidity (near-miss is a newly recognised tool that identifies women at highest risk of maternal death and helps allocate resources especially in low income countries. This study aims to i. document the frequency and nature of maternal near-miss at hospital level in Damascus, Capital of Syria, ii. evaluate the level of care at maternal life-saving emergency services by comparatively analysing near-misses and maternal mortalities. Methods Retrospective facility-based review of cases of near-miss and maternal mortality that took place in the years 2006-2007 at Damascus Maternity University Hospital, Syria. Near-miss cases were defined based on disease-specific criteria (Filippi 2005 including: haemorrhage, hypertensive disorders in pregnancy, dystocia, infection and anaemia. Main outcomes included maternal mortality ratio (MMR, maternal near miss ratio (MNMR, mortality indices and proportion of near-miss cases and mortality cases to hospital admissions. Results There were 28 025 deliveries, 15 maternal deaths and 901 near-miss cases. The study showed a MNMR of 32.9/1000 live births, a MMR of 54.8/100 000 live births and a relatively low mortality index of 1.7%. Hypertensive disorders (52% and haemorrhage (34% were the top causes of near-misses. Late pregnancy haemorrhage was the leading cause of maternal mortality (60% while sepsis had the highest mortality index (7.4%. Most cases (93% were referred in critical conditions from other facilities; namely traditional birth attendants homes (67%, primary (5% and secondary (10% healthcare unites and private practices (11%. 26% of near-miss cases were admitted to Intensive Care Unit (ICU. Conclusion Near-miss analyses provide valuable information on obstetric care. The study highlights the need to improve antenatal care which would help early identification of high risk pregnancies. It also emphasises the importance of both: developing protocols to

  2. Massive Binary Black Holes in the Cosmic Landscape

    Science.gov (United States)

    Colpi, Monica; Dotti, Massimo

    2011-02-01

    Binary black holes occupy a special place in our quest for understanding the evolution of galaxies along cosmic history. If massive black holes grow at the center of (pre-)galactic structures that experience a sequence of merger episodes, then dual black holes form as inescapable outcome of galaxy assembly, and can in principle be detected as powerful dual quasars. But, if the black holes reach coalescence, during their inspiral inside the galaxy remnant, then they become the loudest sources of gravitational waves ever in the universe. The Laser Interferometer Space Antenna is being developed to reveal these waves that carry information on the mass and spin of these binary black holes out to very large look-back times. Nature seems to provide a pathway for the formation of these exotic binaries, and a number of key questions need to be addressed: How do massive black holes pair in a merger? Depending on the properties of the underlying galaxies, do black holes always form a close Keplerian binary? If a binary forms, does hardening proceed down to the domain controlled by gravitational wave back reaction? What is the role played by gas and/or stars in braking the black holes, and on which timescale does coalescence occur? Can the black holes accrete on flight and shine during their pathway to coalescence? After outlining key observational facts on dual/binary black holes, we review the progress made in tracing their dynamics in the habitat of a gas-rich merger down to the smallest scales ever probed with the help of powerful numerical simulations. N-Body/hydrodynamical codes have proven to be vital tools for studying their evolution, and progress in this field is expected to grow rapidly in the effort to describe, in full realism, the physics of stars and gas around the black holes, starting from the cosmological large scale of a merger. If detected in the new window provided by the upcoming gravitational wave experiments, binary black holes will provide a deep view

  3. Merger of white dwarf-neutron star binaries: Prelude to hydrodynamic simulations in general relativity

    International Nuclear Information System (INIS)

    Paschalidis, Vasileios; MacLeod, Morgan; Baumgarte, Thomas W.; Shapiro, Stuart L.

    2009-01-01

    White dwarf-neutron star binaries generate detectable gravitational radiation. We construct Newtonian equilibrium models of corotational white dwarf-neutron star (WDNS) binaries in circular orbit and find that these models terminate at the Roche limit. At this point the binary will undergo either stable mass transfer (SMT) and evolve on a secular time scale, or unstable mass transfer (UMT), which results in the tidal disruption of the WD. The path a given binary will follow depends primarily on its mass ratio. We analyze the fate of known WDNS binaries and use population synthesis results to estimate the number of LISA-resolved galactic binaries that will undergo either SMT or UMT. We model the quasistationary SMT epoch by solving a set of simple ordinary differential equations and compute the corresponding gravitational waveforms. Finally, we discuss in general terms the possible fate of binaries that undergo UMT and construct approximate Newtonian equilibrium configurations of merged WDNS remnants. We use these configurations to assess plausible outcomes of our future, fully relativistic simulations of these systems. If sufficient WD debris lands on the NS, the remnant may collapse, whereby the gravitational waves from the inspiral, merger, and collapse phases will sweep from LISA through LIGO frequency bands. If the debris forms a disk about the NS, it may fragment and form planets.

  4. Activity coefficients of solutes in binary solvents

    International Nuclear Information System (INIS)

    Gokcen, N.A.

    1982-01-01

    The activity coefficients in dilute ternary systems are discussed in detail by using the Margules equations. Analyses of some relevant data at high temperatures show that the sparingly dissolved solutes in binary solvents follow complex behavior even when the binary solvents are very nearly ideal. It is shown that the activity data on the solute or the binary system cannot permit computation of the remaining activities except for the regular solutions. It is also shown that a fourth-order equation is usually adequate in expressing the activity coefficient of a solute in binary solvents at high temperatures. When the activity data for a binary solvent are difficult to obtain in a certain range of composition, the activity data for a sparingly dissolved solute can be used to supplement determination of the binary activities

  5. Missing Strands? Dealing with Hair Loss

    Science.gov (United States)

    ... 2017 Print this issue Missing Strands? Dealing with Hair Loss En español Send us your comments Hair loss is often associated with men and aging, but ... or their treatments, and many other things cause hair loss. The most common type of hair loss is ...

  6. On testing the missing at random assumption

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    Most approaches to learning from incomplete data are based on the assumption that unobserved values are missing at random (mar). While the mar assumption, as such, is not testable, it can become testable in the context of other distributional assumptions, e.g. the naive Bayes assumption...

  7. Missing mass from low-luminosity stars

    International Nuclear Information System (INIS)

    Hawkins, M.R.S.

    1986-01-01

    Results from a deep photometric survey for low-luminosity stars show a turnup to the luminosity function at faint magnitudes, and reopen the possibility that the missing mass in the solar neighbourhood is made up of stars after all. (author)

  8. Dealing with gene expression missing data.

    Science.gov (United States)

    Brás, L P; Menezes, J C

    2006-05-01

    Compared evaluation of different methods is presented for estimating missing values in microarray data: weighted K-nearest neighbours imputation (KNNimpute), regression-based methods such as local least squares imputation (LLSimpute) and partial least squares imputation (PLSimpute) and Bayesian principal component analysis (BPCA). The influence in prediction accuracy of some factors, such as methods' parameters, type of data relationships used in the estimation process (i.e. row-wise, column-wise or both), missing rate and pattern and type of experiment [time series (TS), non-time series (NTS) or mixed (MIX) experiments] is elucidated. Improvements based on the iterative use of data (iterative LLS and PLS imputation--ILLSimpute and IPLSimpute), the need to perform initial imputations (modified PLS and Helland PLS imputation--MPLSimpute and HPLSimpute) and the type of relationships employed (KNNarray, LLSarray, HPLSarray and alternating PLS--APLSimpute) are proposed. Overall, it is shown that data set properties (type of experiment, missing rate and pattern) affect the data similarity structure, therefore influencing the methods' performance. LLSimpute and ILLSimpute are preferable in the presence of data with a stronger similarity structure (TS and MIX experiments), whereas PLS-based methods (MPLSimpute, IPLSimpute and APLSimpute) are preferable when estimating NTS missing data.

  9. Missed opportunities and inappropriately given vaccines reduce ...

    African Journals Online (AJOL)

    Objectives: To quantify missed opportunities for immunisation, document reasons for their occurrence and evaluate the extent of inappropriately given vaccine doses. Design: A cross sectional study of children under two years of age attending health facilities. Setting: Six health facilities predominantly serving the slums of ...

  10. Determinants Of Missed Opportunities For Immunization Among ...

    African Journals Online (AJOL)

    Factors responsible for the missed opportunities included the attitude of the health worker, prolonged time of waiting to receive vaccine, immunization clashing with other schedules and transportation problem. Respondents' level ofknowledge on immunization and educational background were significantly associated with ...

  11. All hypertopologies are hit-and-miss

    Directory of Open Access Journals (Sweden)

    Somshekhar Naimpally

    2002-04-01

    Full Text Available We solve a long standing problem by showing that all known hypertopologies are hit-and-miss. Our solution is not merely of theoretical importance. This representation is useful in the study of comparison of the Hausdorff-Bourbaki or H-B uniform topologies and the Wijsman topologies among themselves and with others. Up to now some of these comparisons needed intricate manipulations. The H-B uniform topologies were the subject of intense activity in the 1960's in connection with the Isbell-Smith problem. We show that they are proximally locally finite topologies from which the solution to the above problem follows easily. It is known that the Wijsman topology on the hyperspace is the proximal ball (hit-and-miss topology in”nice” metric spaces including the normed linear spaces. With the introduction of a new far-miss topology we show that the Wijsman topology is hit-and-miss for all metric spaces. From this follows a natural generalization of the Wijsman topology to the hyperspace of any T1 space. Several existing results in the literature are easy consequences of our work.

  12. Flash CS4: The Missing Manual

    CERN Document Server

    Grover, Chris

    2008-01-01

    Unlock the power of Flash and bring gorgeous animations to life onscreen. Flash CS4: The Missing Manual includes a complete primer on animation, a guided tour of the program's tools and capabilities, lots of new illustrations, and more details on working with video. Beginners will learn to use the software in no time, and experienced Flash designers will improve their skills.

  13. What's Missing? Anti-Racist Sex Education!

    Science.gov (United States)

    Whitten, Amanda; Sethna, Christabelle

    2014-01-01

    Contemporary sexual health curricula in Canada include information about sexual diversity and queer identities, but what remains missing is any explicit discussion of anti-racist sex education. Although there exists federal and provincial support for multiculturalism and anti-racism in schools, contemporary Canadian sex education omits crucial…

  14. How efficient is estimation with missing data?

    DEFF Research Database (Denmark)

    Karadogan, Seliz; Marchegiani, Letizia; Hansen, Lars Kai

    2011-01-01

    percentages (MDP) using a missing completely at random (MCAR) scheme. We compare three MDTs: pairwise deletion (PW), mean imputation (MI) and a maximum likelihood method that we call complete expectation maximization (CEM). We use a synthetic dataset, the Iris dataset and the Pima Indians Diabetes dataset. We...

  15. Generalized canonical correlation analysis with missing values

    NARCIS (Netherlands)

    M. van de Velden (Michel); Y. Takane

    2009-01-01

    textabstractTwo new methods for dealing with missing values in generalized canonical correlation analysis are introduced. The first approach, which does not require iterations, is a generalization of the Test Equating method available for principal component analysis. In the second approach,

  16. Missed Distal Tracheal Foreign Body in Consecutive ...

    African Journals Online (AJOL)

    2017-05-18

    May 18, 2017 ... Since invention, bronchoscopy has become the gold standard in the diagnosis and extraction of airway FB.[4]. Foreign bodies may be missed at ... Since the discovery by Gustav Killian,[9] extraction of tracheobronchial FB has been accomplished with rigid bronchoscopy which is still considered as the gold.

  17. Missed isolated volar dislocation of the scaphoid

    DEFF Research Database (Denmark)

    Kolby, Lise; Larsen, Søren; Jørring, Stig

    2007-01-01

    A patient presented with volar dislocation of the scaphoid, the diagnosis of which had been missed for two weeks. He was treated with open reduction through a combined volar and dorsal approach with decompression of the median nerve, internal fixation, and a cast for eight weeks. One year postope...... postoperatively the functional result was good. A radiograph showed no sign of avascular necrosis....

  18. Missed opportunities for immunisation at Kasungu

    African Journals Online (AJOL)

    work. Some outreach and static clinics still concen- trate their EPI activities on infants and children and largely ignore the mothers who accompany them. Health workers ... sungu District Hospital (KDH) were surveyed. Six. Health Centres ... Table 2 Missed Dpponunities for Immunisation ofEPI Tat'get Gt'Oups at Kmungu ...

  19. Pulsar magnetospheres in binary systems

    Science.gov (United States)

    Ershkovich, A. I.; Dolan, J. F.

    1985-01-01

    The criterion for stability of a tangential discontinuity interface in a magnetized, perfectly conducting inviscid plasma is investigated by deriving the dispersion equation including the effects of both gravitational and centrifugal acceleration. The results are applied to neutron star magnetospheres in X-ray binaries. The Kelvin-Helmholtz instability appears to be important in determining whether MHD waves of large amplitude generated by instability may intermix the plasma effectively, resulting in accretion onto the whole star as suggested by Arons and Lea and leading to no X-ray pulsar behavior.

  20. The structures of binary compounds

    CERN Document Server

    Hafner, J; Jensen, WB; Majewski, JA; Mathis, K; Villars, P; Vogl, P; de Boer, FR

    1990-01-01

    - Up-to-date compilation of the experimental data on the structures of binary compounds by Villars and colleagues. - Coloured structure maps which order the compounds into their respective structural domains and present for the first time the local co-ordination polyhedra for the 150 most frequently occurring structure types, pedagogically very helpful and useful in the search for new materials with a required crystal structure. - Crystal co-ordination formulas: a flexible notation for the interpretation of solid-state structures by chemist Bill Jensen. - Recent important advances in unders

  1. Tomographic reconstruction of binary fields

    International Nuclear Information System (INIS)

    Roux, Stéphane; Leclerc, Hugo; Hild, François

    2012-01-01

    A novel algorithm is proposed for reconstructing binary images from their projection along a set of different orientations. Based on a nonlinear transformation of the projection data, classical back-projection procedures can be used iteratively to converge to the sought image. A multiscale implementation allows for a faster convergence. The algorithm is tested on images up to 1 Mb definition, and an error free reconstruction is achieved with a very limited number of projection data, saving a factor of about 100 on the number of projections required for classical reconstruction algorithms.

  2. Young and Waltzing Binary Stars

    Science.gov (United States)

    2001-10-01

    ADONIS Observes Low-mass Eclipsing System in Orion Summary A series of very detailed images of a binary system of two young stars have been combined into a movie . In merely 3 days, the stars swing around each other. As seen from the earth, they pass in front of each other twice during a full revolution, producing eclipses during which their combined brightness diminishes . A careful analysis of the orbital motions has now made it possible to deduce the masses of the two dancing stars . Both turn out to be about as heavy as our Sun. But while the Sun is about 4500 million years old, these two stars are still in their infancy. They are located some 1500 light-years away in the Orion star-forming region and they probably formed just 10 million years ago . This is the first time such an accurate determination of the stellar masses could be achieved for a young binary system of low-mass stars . The new result provides an important piece of information for our current understanding of how young stars evolve. The observations were obtained by a team of astronomers from Italy and ESO [1] using the ADaptive Optics Near Infrared System (ADONIS) on the 3.6-m telescope at the ESO La Silla Observatory. PR Photo 29a/01 : The RXJ 0529.4+0041 system before primary eclipse PR Photo 29b/01 : The RXJ 0529.4+0041 system at mid-primary eclipse PR Photo 29c/01 : The RXJ 0529.4+0041 system after primary eclipse PR Photo 29d/01 : The RXJ 0529.4+0041 system before secondary eclipse PR Photo 29e/01 : The RXJ 0529.4+0041 system at mid-secondary eclipse PR Photo 29f/01 : The RXJ 0529.4+0041 system after secondary eclipse PR Video Clip 06/01 : Video of the RXJ 0529.4+0041 system Binary stars and stellar masses Since some time, astronomers have noted that most stars seem to form in binary or multiple systems. This is quite fortunate, as the study of binary stars is the only way in which it is possible to measure directly one of the most fundamental quantities of a star, its mass. The mass of a

  3. Microlensing Signature of Binary Black Holes

    Science.gov (United States)

    Schnittman, Jeremy; Sahu, Kailash; Littenberg, Tyson

    2012-01-01

    We calculate the light curves of galactic bulge stars magnified via microlensing by stellar-mass binary black holes along the line-of-sight. We show the sensitivity to measuring various lens parameters for a range of survey cadences and photometric precision. Using public data from the OGLE collaboration, we identify two candidates for massive binary systems, and discuss implications for theories of star formation and binary evolution.

  4. Critical thinking, delegation, and missed care in nursing practice.

    Science.gov (United States)

    Bittner, Nancy Phoenix; Gravlin, Gayle

    2009-03-01

    The aim of this study was to understand how nurses use critical thinking to delegate nursing care. Nurses must synthesize large amounts of information and think through complex and often emergent clinical situations when making critical decisions about patient care, including delegation. A qualitative, descriptive study was used in this article. Before delegating, nurses reported considering patient condition, competency, experience, and workload of unlicensed assistive personnel (UAP). Nurses expected UAP to report significant findings and have higher level knowledge, including assessment and prioritizing skills. Successful delegation was dependent on the relationship between the RN and the UAP, communication, system support, and nursing leadership. Nurses reported frequent instances of missed or omitted routine care. Findings from this project provide insight into factors that influence delegation effectiveness. These can guide CNOs and frontline nurse leaders to focus on implementing strategies to mitigate the consequence of missed care. Ineffective delegation of basic nursing care can result in poor patient outcomes, potentially impacting quality measures, satisfaction, and reimbursement for the institution.

  5. Missed retinal breaks in rhegmatogenous retinal detachment

    Directory of Open Access Journals (Sweden)

    Brijesh Takkar

    2016-12-01

    Full Text Available AIM: To evaluate the causes and associations of missed retinal breaks (MRBs and posterior vitreous detachment (PVD in patients with rhegmatogenous retinal detachment (RRD. METHODS: Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and 191 patients were included for analysis of PVD, depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations. RESULTS: Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs (P=0.033 with the odds of missing a retinal break being 1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy (PVR and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae, pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD. Traumatic RRDs were rarely associated with PVD. CONCLUSION: Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD.

  6. Survival of planets around shrinking stellar binaries.

    Science.gov (United States)

    Muñoz, Diego J; Lai, Dong

    2015-07-28

    The discovery of transiting circumbinary planets by the Kepler mission suggests that planets can form efficiently around binary stars. None of the stellar binaries currently known to host planets has a period shorter than 7 d, despite the large number of eclipsing binaries found in the Kepler target list with periods shorter than a few days. These compact binaries are believed to have evolved from wider orbits into their current configurations via the so-called Lidov-Kozai migration mechanism, in which gravitational perturbations from a distant tertiary companion induce large-amplitude eccentricity oscillations in the binary, followed by orbital decay and circularization due to tidal dissipation in the stars. Here we explore the orbital evolution of planets around binaries undergoing orbital decay by this mechanism. We show that planets may survive and become misaligned from their host binary, or may develop erratic behavior in eccentricity, resulting in their consumption by the stars or ejection from the system as the binary decays. Our results suggest that circumbinary planets around compact binaries could still exist, and we offer predictions as to what their orbital configurations should be like.

  7. Contact Binaries on Their Way Towards Merging

    Science.gov (United States)

    Gazeas, K.

    2015-07-01

    Contact binaries are the most frequently observed type of eclipsing star system. They are small, cool, low-mass binaries belonging to a relatively old stellar population. They follow certain empirical relationships that closely connect a number of physical parameters with each other, largely because of constraints coming from the Roche geometry. As a result, contact binaries provide an excellent test of stellar evolution, specifically for stellar merger scenarios. Observing campaigns by many authors have led to the cataloging of thousands of contact binaries and enabled statistical studies of many of their properties. A large number of contact binaries have been found to exhibit extraordinary behavior, requiring follow-up observations to study their peculiarities in detail. For example, a doubly-eclipsing quadruple system consisting of a contact binary and a detached binary is a highly constrained system offering an excellent laboratory to test evolutionary theories for binaries. A new observing project was initiated at the University of Athens in 2012 in order to investigate the possible lower limit for the orbital period of binary systems before coalescence, prior to merging.

  8. Airline Safety Improvement Through Experience with Near-Misses: A Cautionary Tale.

    Science.gov (United States)

    Madsen, Peter; Dillon, Robin L; Tinsley, Catherine H

    2016-05-01

    In recent years, the U.S. commercial airline industry has achieved unprecedented levels of safety, with the statistical risk associated with U.S. commercial aviation falling to 0.003 fatalities per 100 million passengers. But decades of research on organizational learning show that success often breeds complacency and failure inspires improvement. With accidents as rare events, can the airline industry continue safety advancements? This question is complicated by the complex system in which the industry operates where chance combinations of multiple factors contribute to what are largely probabilistic (rather than deterministic) outcomes. Thus, some apparent successes are realized because of good fortune rather than good processes, and this research intends to bring attention to these events, the near-misses. The processes that create these near-misses could pose a threat if multiple contributing factors combine in adverse ways without the intervention of good fortune. Yet, near-misses (if recognized as such) can, theoretically, offer a mechanism for continuing safety improvements, above and beyond learning gleaned from observable failure. We test whether or not this learning is apparent in the airline industry. Using data from 1990 to 2007, fixed effects Poisson regressions show that airlines learn from accidents (their own and others), and from one category of near-misses-those where the possible dangers are salient. Unfortunately, airlines do not improve following near-miss incidents when the focal event has no clear warnings of significant danger. Therefore, while airlines need to and can learn from certain near-misses, we conclude with recommendations for improving airline learning from all near-misses. © 2015 Society for Risk Analysis.

  9. Understanding conflict as a (missed) opportunity for social development

    DEFF Research Database (Denmark)

    Ravn, Ib

    and the parties may learn and grow, or it may be missed--lost in suppression, projections, fear, etc. Conflict is thus seen, not as an outcome of regrettably incompatible goals or activities, but as an active potential for learning and development. Some implications for conflict resolution practice are outlined.......In the literature on conflict management, conflict is usually defined in terms of incompatible goals and activities. In contrast, Thomas (1992), making no reference to such incompatibilities, defines conflict as a process that begins when one party feels negatively affected by another. This paper...... modifies and extends Thomas’ definition thus: One party is in conflict with another when he or she 1. experiences psychological or physical pain, 2. holds the other party to be responsible for this pain, and 3. does not accept this situation. This definition is nested in a theoretical perspective that sees...

  10. Fabricating binary optics: An overview of binary optics process technology

    Science.gov (United States)

    Stern, Margaret B.

    1993-01-01

    A review of binary optics processing technology is presented. Pattern replication techniques have been optimized to generate high-quality efficient microoptics in visible and infrared materials. High resolution optical photolithography and precision alignment is used to fabricate maximally efficient fused silica diffractive microlenses at lambda = 633 nm. The degradation in optical efficiency of four-phase-level fused silica microlenses resulting from an intentional 0.35 micron translational error has been systematically measured as a function of lens speed (F/2 - F/60). Novel processes necessary for high sag refractive IR microoptics arrays, including deep anisotropic Si-etching, planarization of deep topography and multilayer resist techniques, are described. Initial results are presented for monolithic integration of photonic and microoptic systems.

  11. Incomplete Early Childhood Immunization Series and Missing Fourth DTaP Immunizations; Missed Opportunities or Missed Visits?

    Science.gov (United States)

    Robison, Steve G

    2013-01-01

    The successful completion of early childhood immunizations is a proxy for overall quality of early care. Immunization statuses are usually assessed by up-to-date (UTD) rates covering combined series of different immunizations. However, series UTD rates often only bear on which single immunization is missing, rather than the success of all immunizations. In the US, most series UTD rates are limited by missing fourth DTaP-containing immunizations (diphtheria/tetanus/pertussis) due at 15 to 18 months of age. Missing 4th DTaP immunizations are associated either with a lack of visits at 15 to 18 months of age, or to visits without immunizations. Typical immunization data however cannot distinguish between these two reasons. This study compared immunization records from the Oregon ALERT IIS with medical encounter records for two-year olds in the Oregon Health Plan. Among those with 3 valid DTaPs by 9 months of age, 31.6% failed to receive a timely 4th DTaP; of those without a 4th DTaP, 42.1% did not have any provider visits from 15 through 18 months of age, while 57.9% had at least one provider visit. Those with a 4th DTaP averaged 2.45 encounters, while those with encounters but without 4th DTaPs averaged 2.23 encounters.

  12. Missing data treatments matter: an analysis of multiple imputation for anterior cervical discectomy and fusion procedures.

    Science.gov (United States)

    Ondeck, Nathaniel T; Fu, Michael C; Skrip, Laura A; McLynn, Ryan P; Cui, Jonathan J; Basques, Bryce A; Albert, Todd J; Grauer, Jonathan N

    2018-04-09

    The presence of missing data is a limitation of large datasets, including the National Surgical Quality Improvement Program (NSQIP). In addressing this issue, most studies use complete case analysis, which excludes cases with missing data, thus potentially introducing selection bias. Multiple imputation, a statistically rigorous approach that approximates missing data and preserves sample size, may be an improvement over complete case analysis. The present study aims to evaluate the impact of using multiple imputation in comparison with complete case analysis for assessing the associations between preoperative laboratory values and adverse outcomes following anterior cervical discectomy and fusion (ACDF) procedures. This is a retrospective review of prospectively collected data. Patients undergoing one-level ACDF were identified in NSQIP 2012-2015. Perioperative adverse outcome variables assessed included the occurrence of any adverse event, severe adverse events, and hospital readmission. Missing preoperative albumin and hematocrit values were handled using complete case analysis and multiple imputation. These preoperative laboratory levels were then tested for associations with 30-day postoperative outcomes using logistic regression. A total of 11,999 patients were included. Of this cohort, 63.5% of patients had missing preoperative albumin and 9.9% had missing preoperative hematocrit. When using complete case analysis, only 4,311 patients were studied. The removed patients were significantly younger, healthier, of a common body mass index, and male. Logistic regression analysis failed to identify either preoperative hypoalbuminemia or preoperative anemia as significantly associated with adverse outcomes. When employing multiple imputation, all 11,999 patients were included. Preoperative hypoalbuminemia was significantly associated with the occurrence of any adverse event and severe adverse events. Preoperative anemia was significantly associated with the

  13. Radial Velocities of 41 Kepler Eclipsing Binaries

    Science.gov (United States)

    Matson, Rachel A.; Gies, Douglas R.; Guo, Zhao; Williams, Stephen J.

    2017-12-01

    Eclipsing binaries are vital for directly determining stellar parameters without reliance on models or scaling relations. Spectroscopically derived parameters of detached and semi-detached binaries allow us to determine component masses that can inform theories of stellar and binary evolution. Here we present moderate resolution ground-based spectra of stars in close binary systems with and without (detected) tertiary companions observed by NASA’s Kepler mission and analyzed for eclipse timing variations. We obtain radial velocities and spectroscopic orbits for five single-lined and 35 double-lined systems, and confirm one false positive eclipsing binary. For the double-lined spectroscopic binaries, we also determine individual component masses and examine the mass ratio {M}2/{M}1 distribution, which is dominated by binaries with like-mass pairs and semi-detached classical Algol systems that have undergone mass transfer. Finally, we constrain the mass of the tertiary component for five double-lined binaries with previously detected companions.

  14. BHDD: Primordial black hole binaries code

    Science.gov (United States)

    Kavanagh, Bradley J.; Gaggero, Daniele; Bertone, Gianfranco

    2018-06-01

    BHDD (BlackHolesDarkDress) simulates primordial black hole (PBH) binaries that are clothed in dark matter (DM) halos. The software uses N-body simulations and analytical estimates to follow the evolution of PBH binaries formed in the early Universe.

  15. Main Memory Implementations for Binary Grouping

    OpenAIRE

    May, Norman; Moerkotte, Guido

    2005-01-01

    An increasing number of applications depend on efficient storage and analysis features for XML data. Hence, query optimization and efficient evaluation techniques for the emerging XQuery standard become more and more important. Many XQuery queries require nested expressions. Unnesting them often introduces binary grouping. We introduce several algorithms implementing binary grouping and analyze their time and space complexity. Experiments demonstrate their performance.

  16. Eliciting Subjective Probabilities with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    objective probabilities. Drawing a sample from the same subject population, we find evidence that the binary lottery procedure induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation...

  17. Bondi-Hoyle-Lyttleton Accretion onto Binaries

    Science.gov (United States)

    Antoni, Andrea; MacLeod, Morgan; Ramírez-Ruiz, Enrico

    2018-01-01

    Binary stars are not rare. While only close binary stars will eventually interact with one another, even the widest binary systems interact with their gaseous surroundings. The rates of accretion and the gaseous drag forces arising in these interactions are the key to understanding how these systems evolve. This poster examines accretion flows around a binary system moving supersonically through a background gas. We perform three-dimensional hydrodynamic simulations of Bondi-Hoyle-Lyttleton accretion using the adaptive mesh refinement code FLASH. We simulate a range of values of semi-major axis of the orbit relative to the gravitational focusing impact parameter of the pair. On large scales, gas is gravitationally focused by the center-of-mass of the binary, leading to dynamical friction drag and to the accretion of mass and momentum. On smaller scales, the orbital motion imprints itself on the gas. Notably, the magnitude and direction of the forces acting on the binary inherit this orbital dependence. The long-term evolution of the binary is determined by the timescales for accretion, slow down of the center-of-mass, and decay of the orbit. We use our simulations to measure these timescales and to establish a hierarchy between them. In general, our simulations indicate that binaries moving through gaseous media will slow down before the orbit decays.

  18. Binary Relations as a Foundation of Mathematics

    NARCIS (Netherlands)

    Kuper, Jan; Barendsen, E.; Capretta, V.; Geuvers, H.; Niqui, M.

    2007-01-01

    We describe a theory for binary relations in the Zermelo-Fraenkel style. We choose for ZFCU, a variant of ZFC Set theory in which the Axiom of Foundation is replaced by an axiom allowing for non-wellfounded sets. The theory of binary relations is shown to be equi-consistent ZFCU by constructing a

  19. RELATIONSHIP BETWEEN FLASH POINTS OF SOME BINARY ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    Miscellaneous binary blends containing solvent neutral-150 (SN-150), ... viscosity, the flash point test has always been a standard part of a lubricant's specification. ... between structure and flash points of organic compounds [5-12] and fuels [13, 14]. ... in binary mixtures, the gaps between flash points would be high enough.

  20. The origin of the RS CVn binaries

    International Nuclear Information System (INIS)

    Biermann, P.

    1976-01-01

    Six possible origins for the RS CVn binaries are considered based on the following possibilities. RS CVn binaries might now be either pre-main-sequence or post-main-sequence. A pre-main-sequence binary might not always have been a binary but might have resulted from fission of a rapidly rotating single pre-main-sequence star. The main-sequence counterparts might be either single stars or binaries. To decide which of the six origins is possible, the following observed data for the RS CVn binaries are considered: total mass, total angular momentum, lack of observed connection with regions of star formation, large space density, kinematical age, and the visual companion of WW Dra. In addition lifetimes and space densities of single stars and other types of binaries are considered. The only origin possible is that the RS CVn binaries are in a thermal phase following fission of a main-sequence single star. In this explanation the single star had a rapidly rotating core which became unstable due to the core contraction which made it begin to evolve off the main sequence. The present Be stars might be examples of such parent single stars. (Auth.)

  1. Exploring the Influence of Nursing Work Environment and Patient Safety Culture on Missed Nursing Care in Korea.

    Science.gov (United States)

    Kim, Kyoung-Ja; Yoo, Moon Sook; Seo, Eun Ji

    2018-04-20

    This study aimed to explore the influence of nurse work environment and patient safety culture in hospital on instances of missed nursing care in South Korea. A cross-sectional design was used, in which a structured questionnaire was administered to 186 nurses working at a tertiary university hospital. Data were analyzed using descriptive statistics, t-test or ANOVA, Pearson correlation and multiple regression analysis. Missed nursing care was found to be correlated with clinical career, nursing work environment and patient safety culture. The regression model explained approximately 30.3 % of missed nursing care. Meanwhile, staffing and resource adequacy (β = -.31, p = .001), nurse manager ability, leadership and support of nurses (β = -.26, p = .004), clinical career (β = -.21, p = .004), and perception on patient safety culture within unit (β = -.19, p = .041) were determined to be influencing factors on missed nursing care. This study has significance as it suggested that missed nursing care is affected by work environment factors within unit. This means that missed nursing care is a unit outcome affected by nurse work environment factors and patient safety culture. Therefore, missed nursing care can be managed through the implementation of interventions that promote a positive nursing work environment and patient safety culture. Copyright © 2018. Published by Elsevier B.V.

  2. Congenitally missing mandibular second premolars: clinical options.

    Science.gov (United States)

    Kokich, Vincent G; Kokich, Vincent O

    2006-10-01

    Congenital absence of mandibular second premolars affects many orthodontic patients. The orthodontist must make the proper decision at the appropriate time regarding management of the edentulous space. These spaces can be closed or left open. If the space will be left open for an eventual restoration, the keys during orthodontic treatment are to create the correct amount of space and to leave the alveolar ridge in an ideal condition for a future restoration. If the space will be closed, the clinician must avoid any detrimental alterations to the occlusion and the facial profile. Some early decisions that the orthodontist makes for a patient whose mandibular second premolars are congenitally missing will affect his or her dental health for a lifetime. Therefore, the correct decision must be made at the appropriate time. In this article, we present and discuss various treatment alternatives for managing orthodontic patients with at least 1 congenitally missing mandibular second premolar.

  3. The case of the missing third.

    Science.gov (United States)

    Robertson, Robin

    2005-01-01

    How is it that form arises out of chaos? In attempting to deal with this primary question, time and again a "Missing Third" is posited that lies between extremes. The problem of the "Missing Third" can be traced through nearly the entire history of thought. The form it takes, the problems that arise from it, the solutions suggested for resolving it, are each representative of an age. This paper traces the issue from Plato and Parmenides in the 4th--5th centuries, B.C.; to Neoplatonism in the 3rd--5th centuries; to Locke and Descartes in the 17th century; on to Berkeley and Kant in the 18th century; Fechner and Wundt in the 19th century; to behaviorism and Gestalt psychology, Jung, early in the 20th century, ethology and cybernetics later in the 20th century, then culminates late in the 20th century, with chaos theory.

  4. iLife '05 The Missing Manual

    CERN Document Server

    Pogue, David

    2005-01-01

    The incomparable iLife '05 is the must-have multimedia suite for everyone who owns a Mac--and the envy of everyone who doesn't. iLife '05: The Missing Manual is the definitive iLife '05 book--and what should have come with the suite. There's no better guide to your iLife experience than the #1 bestselling Macintosh author and expert--and Missing Manual series creator--David Pogue. Totally objective and utterly in-the-know, Pogue highlights the newest features, changes, and improvements of iLife '05, covers the capabilities and limitations of each program within the suite, and delivers count

  5. Absence of missing mass in clusters

    Energy Technology Data Exchange (ETDEWEB)

    Fesenko, B.I.

    1981-01-01

    The evaluation of the radial-velocity dispersion in clusters of galaxies is considered by using order statistics to reduce the distortions introduced by foreground and background galaxies and by large errors in velocity measurement. For four nearby clusters of galaxies, including the Coma cluster, velocity dispersions are obtained which are approximately four times lower than previously reported values. It is found that more remote galaxies exhibit the same tendency to a reduction in missing mass. A detailed examination of the statistical properties of galaxies in the Virgo cluster reveals that the cluster might not actually exist, but may be just a large excess in the number density of bright galaxies, possibly the result of an increase in the visibility of objects in the appropriate directions. It is concluded that the presence of a large amount of missing mass in clusters of galaxies is yet to be proven.

  6. Coping with missing data in phase III pivotal registration trials: Tolvaptan in subjects with kidney disease, a case study.

    Science.gov (United States)

    Ouyang, John; Carroll, Kevin J; Koch, Gary; Li, Junfang

    2017-07-01

    Missing data cause challenging issues, particularly in phase III registration trials, as highlighted by the European Medicines Agency (EMA) and the US National Research Council. We explore, as a case study, how the issues from missing data were tackled in a double-blind phase III trial in subjects with autosomal dominant polycystic kidney disease. A total of 1445 subjects were randomized in a 2:1 ratio to receive active treatment (tolvaptan), or placebo. The primary outcome, the rate of change in total kidney volume, favored tolvaptan (P outline the analyses undertaken to address the issue of missing data thoroughly. "Tipping point analyses" were performed to explore how extreme and detrimental outcomes among subjects with missing data must be to overturn the positive treatment effect attained in those subjects who had complete data. Nonparametric rank-based analyses were also performed accounting for missing data. In conclusion, straightforward and transparent analyses directly taking into account missing data convincingly support the robustness of the preplanned analyses on the primary and secondary endpoints. Tolvaptan was confirmed to be effective in slowing total kidney volume growth, which is considered an efficacy endpoint by EMA, and in lessening the decline in renal function in patients with autosomal dominant polycystic kidney disease. Copyright © 2017 John Wiley & Sons, Ltd.

  7. MOLDOVA: MISSED ADVANTAGES OF EURASIAN INTEGRATION

    Directory of Open Access Journals (Sweden)

    Ludmila Vasiljevna Fokina

    2015-01-01

    Full Text Available The article is devoted to potentially missed advantages of Eurasian integration (EAEU for Moldova. Special attention is given to the branches in which the country could get evident advantages including agriculture, power engineering, external trade ties with the EAEU countries. Possible positive effects of Eurasian integration in solution of the Transnistrian problem, in the sphere of labour migration and other fields are also shown.

  8. Photoshop Elements 6 The Missing Manual

    CERN Document Server

    Brundage, Barbara

    2009-01-01

    With Photoshop Elements 6, the most popular photo-editing program on Earth just keeps getting better. It's perfect for scrapbooking, email-ready slideshows, Web galleries, you name it. But knowing what to do and when is tricky. That's why our Missing Manual is the bestselling book on the topic. This fully revised guide explains not only how the tools and commands work, but when to use them.

  9. Missing level corrections using neutron spacings

    International Nuclear Information System (INIS)

    Mitchell, G.E.; Shriner, J.F. Jr.

    2009-11-01

    Nuclear level densities are very important for a wide variety of pure and applied neutron physics. Most of the relevant information is obtained from neutron resonance data. The key correction to the raw experimental data is for missing levels. All of the standard correction methods assume that the neutron resonances obey the predictions of the Gaussian Orthogonal Ensemble version of Random Matrix Theory (RMT) and utilize comparison with the Porter-Thomas distribution of reduced widths in order to determine the fraction of missing levels. Here we adopt an alternate approach, comparing the neutron data with the predictions of RMT for eigenvalue statistics. Since in RMT the widths and eigenvalues are independent, analysis of the eigenvalues provides an independent analysis of the same data set. We summarize recent work in this area using the nearest neighbour spacing distribution, and we also develop tests that utilize several other eigenvalue statistics to provide additional estimates of the missing fraction of levels. These additional statistics include the key test for long range order - the Dyson-Mehta Δ 3 statistic - as well as the thermodynamic energy (that arises from Dyson's Circular Orthogonal Ensemble), the linear correlation coefficient of adjacent spacings (a measure of short range anti-correlation), and a statistic related to the Q statistic defined by Dyson and Mehta in the early 1960s. Developed FORTRAN code is available at http://www-nds.iaea.org/missing-levels/. These tests are applied to the s-wave neutron resonances in n + 238 U and n + 232 Th. The results for 238 U are consistent with each other and raise some issues concerning data purity. For the 232 Th data, all of the tests are in excellent agreement. (author)

  10. iWork '09 The Missing Manual

    CERN Document Server

    Clark, Josh

    2009-01-01

    With iWork '09: The Missing Manual, you'll quickly learn everything you need to know about Apple's incredible productivity programs, including the Pages word-processor, the Numbers spreadsheet, and the Keynote presentation program that Al Gore and Steve Jobs made famous. This book gives you crystal-clear and jargon-free explanations of iWork's capabilities, advantages, and limitations to help you produce stunning documents and cinema-quality digital presentations in no time.

  11. Mass Transfer in Mira-Type Binaries

    Directory of Open Access Journals (Sweden)

    Mohamed S.

    2012-06-01

    Full Text Available Detached, symbiotic binaries are generally assumed to interact via Bondi-Hoyle-Littleton (BHL wind accretion. However, the accretion rates and outflow geometries that result from this mass-transfer mechanism cannot adequately explain the observations of the nearest and best studied symbiotic binary, Mira, or the formation of some post-AGB binaries, e.g. barium stars. We propose a new mass-transfer mode for Mira-type binaries, which we call ‘wind Roche-lobe overflow’ (WRLOF, and which we demonstrate with 3D hydrodynamic simulations. Importantly, we show that the circumstellar outflows which result from WRLOF tend to be highly aspherical and strongly focused towards the binary orbital plane. Furthermore, the subsequent mass-transfer rates are at least an order of magnitude greater than the analogous BHL values. We discuss the implications of these results for the shaping of bipolar (proto-planetary nebulae and other related systems.

  12. Logistic chaotic maps for binary numbers generations

    International Nuclear Information System (INIS)

    Kanso, Ali; Smaoui, Nejib

    2009-01-01

    Two pseudorandom binary sequence generators, based on logistic chaotic maps intended for stream cipher applications, are proposed. The first is based on a single one-dimensional logistic map which exhibits random, noise-like properties at given certain parameter values, and the second is based on a combination of two logistic maps. The encryption step proposed in both algorithms consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. A threshold function is applied to convert the floating-point iterates into binary form. Experimental results show that the produced sequences possess high linear complexity and very good statistical properties. The systems are put forward for security evaluation by the cryptographic committees.

  13. Phonons in fcc binary alloys

    International Nuclear Information System (INIS)

    Sharma, Amita; Rathore, R.P.S.

    1992-01-01

    Born-Mayer potential has been modified to account for the unpaired (three body) forces among the common nearest neighbours of the ordered binary fcc alloys i.e. Ni 3 Fe 7 , Ni 5 Fe 5 and Ni 75 Fe 25 . The three body potential is added to the two body form of Morse to formalize the total interaction potential. Measured inverse ionic compressibility, cohesive energy, lattice constant and one measured phonon frequency are used to evaluate the defining parameters of the potential. The potential seeks to bring about the binding among 140 and 132 atoms though pair wise (two body) and non-pair wise (three body) forces respectively. The phonon-dispersion relations obtained by solving the secular equation are compared with the experimental findings on the aforesaid alloys. (author). 19 refs., 3 figs

  14. Uncovering missing links with cold ends

    Science.gov (United States)

    Zhu, Yu-Xiao; Lü, Linyuan; Zhang, Qian-Ming; Zhou, Tao

    2012-11-01

    To evaluate the performance of prediction of missing links, the known data are randomly divided into two parts, the training set and the probe set. We argue that this straightforward and standard method may lead to terrible bias, since in real biological and information networks, missing links are more likely to be links connecting low-degree nodes. We therefore study how to uncover missing links with low-degree nodes, namely links in the probe set are of lower degree products than a random sampling. Experimental analysis on ten local similarity indices and four disparate real networks reveals a surprising result that the Leicht-Holme-Newman index [E.A. Leicht, P. Holme, M.E.J. Newman, Vertex similarity in networks, Phys. Rev. E 73 (2006) 026120] performs the best, although it was known to be one of the worst indices if the probe set is a random sampling of all links. We further propose an parameter-dependent index, which considerably improves the prediction accuracy. Finally, we show the relevance of the proposed index to three real sampling methods: acquaintance sampling, random-walk sampling and path-based sampling.

  15. MISSE 6 Polymer Film Tensile Experiment

    Science.gov (United States)

    Miller, Sharon K. R.; Dever, Joyce A.; Banks, Bruce A.; Waters, Deborah L.; Sechkar, Edward; Kline, Sara

    2010-01-01

    The Polymer Film Tensile Experiment (PFTE) was flown as part of Materials International Space Station Experiment 6 (MISSE 6). The purpose of the experiment was to expose a variety of polymer films to the low Earth orbital environment under both relaxed and tension conditions. The polymers selected are those commonly used for spacecraft thermal control and those under consideration for use in spacecraft applications such as sunshields, solar sails, and inflatable and deployable structures. The dog-bone shaped samples of polymers that were flown were exposed on both the side of the MISSE 6 Passive Experiment Container (PEC) that was facing into the ram direction (receiving atomic oxygen, ultraviolet (UV) radiation, ionizing radiation, and thermal cycling) and the wake facing side (which was supposed to have experienced predominantly the same environmental effects except for atomic oxygen which was present due to reorientation of the International Space Station). A few of the tensile samples were coated with vapor deposited aluminum on the back and wired to determine the point in the flight when the tensile sample broke as recorded by a change in voltage that was stored on battery powered data loggers for post flight retrieval and analysis. The data returned on the data loggers was not usable. However, post retrieval observation and analysis of the samples was performed. This paper describes the preliminary analysis and observations of the polymers exposed on the MISSE 6 PFTE.

  16. Planned Missing Data Designs in Educational Psychology Research

    NARCIS (Netherlands)

    Rhemtulla, M.; Hancock, G.R.

    2016-01-01

    Although missing data are often viewed as a challenge for applied researchers, in fact missing data can be highly beneficial. Specifically, when the amount of missing data on specific variables is carefully controlled, a balance can be struck between statistical power and research costs. This

  17. Missing value imputation for epistatic MAPs

    LENUS (Irish Health Repository)

    Ryan, Colm

    2010-04-20

    Abstract Background Epistatic miniarray profiling (E-MAPs) is a high-throughput approach capable of quantifying aggravating or alleviating genetic interactions between gene pairs. The datasets resulting from E-MAP experiments typically take the form of a symmetric pairwise matrix of interaction scores. These datasets have a significant number of missing values - up to 35% - that can reduce the effectiveness of some data analysis techniques and prevent the use of others. An effective method for imputing interactions would therefore increase the types of possible analysis, as well as increase the potential to identify novel functional interactions between gene pairs. Several methods have been developed to handle missing values in microarray data, but it is unclear how applicable these methods are to E-MAP data because of their pairwise nature and the significantly larger number of missing values. Here we evaluate four alternative imputation strategies, three local (Nearest neighbor-based) and one global (PCA-based), that have been modified to work with symmetric pairwise data. Results We identify different categories for the missing data based on their underlying cause, and show that values from the largest category can be imputed effectively. We compare local and global imputation approaches across a variety of distinct E-MAP datasets, showing that both are competitive and preferable to filling in with zeros. In addition we show that these methods are effective in an E-MAP from a different species, suggesting that pairwise imputation techniques will be increasingly useful as analogous epistasis mapping techniques are developed in different species. We show that strongly alleviating interactions are significantly more difficult to predict than strongly aggravating interactions. Finally we show that imputed interactions, generated using nearest neighbor methods, are enriched for annotations in the same manner as measured interactions. Therefore our method potentially

  18. Rational and Boundedly Rational Behavior in a Binary Choice Sender-Receiver Game

    Science.gov (United States)

    Landi, Massimiliano; Colucci, Domenico

    2008-01-01

    The authors investigate the strategic rationale behind the message sent by Osama bin Laden on the eve of the 2004 U.S. Presidential elections. They model this situation as a signaling game in which a population of receivers takes a binary choice, the outcome is decided by majority rule, sender and receivers have conflicting interests, and there is…

  19. PERIODIC SIGNALS IN BINARY MICROLENSING EVENTS

    International Nuclear Information System (INIS)

    Guo, Xinyi; Stefano, Rosanne Di; Esin, Ann; Taylor, Jeffrey

    2015-01-01

    Gravitational microlensing events are powerful tools for the study of stellar populations. In particular, they can be used to discover and study a variety of binary systems. A large number of binary lenses have already been found through microlensing surveys and a few of these systems show strong evidence of orbital motion on the timescale of the lensing event. We expect that more binary lenses of this kind will be detected in the future. For binaries whose orbital period is comparable to the event duration, the orbital motion can cause the lensing signal to deviate drastically from that of a static binary lens. The most striking property of such light curves is the presence of quasi-periodic features, which are produced as the source traverses the same regions in the rotating lens plane. These repeating features contain information about the orbital period of the lens. If this period can be extracted, then much can be learned about the lensing system even without performing time-consuming, detailed light-curve modeling. However, the relative transverse motion between the source and the lens significantly complicates the problem of period extraction. To resolve this difficulty, we present a modification of the standard Lomb–Scargle periodogram analysis. We test our method for four representative binary lens systems and demonstrate its efficiency in correctly extracting binary orbital periods

  20. Topological and categorical properties of binary trees

    Directory of Open Access Journals (Sweden)

    H. Pajoohesh

    2008-04-01

    Full Text Available Binary trees are very useful tools in computer science for estimating the running time of so-called comparison based algorithms, algorithms in which every action is ultimately based on a prior comparison between two elements. For two given algorithms A and B where the decision tree of A is more balanced than that of B, it is known that the average and worst case times of A will be better than those of B, i.e., ₸A(n ≤₸B(n and TWA (n≤TWB (n. Thus the most balanced and the most imbalanced binary trees play a main role. Here we consider them as semilattices and characterize the most balanced and the most imbalanced binary trees by topological and categorical properties. Also we define the composition of binary trees as a commutative binary operation, *, such that for binary trees A and B, A * B is the binary tree obtained by attaching a copy of B to any leaf of A. We show that (T,* is a commutative po-monoid and investigate its properties.

  1. R package to estimate intracluster correlation coefficient with confidence interval for binary data.

    Science.gov (United States)

    Chakraborty, Hrishikesh; Hossain, Akhtar

    2018-03-01

    The Intracluster Correlation Coefficient (ICC) is a major parameter of interest in cluster randomized trials that measures the degree to which responses within the same cluster are correlated. There are several types of ICC estimators and its confidence intervals (CI) suggested in the literature for binary data. Studies have compared relative weaknesses and advantages of ICC estimators as well as its CI for binary data and suggested situations where one is advantageous in practical research. The commonly used statistical computing systems currently facilitate estimation of only a very few variants of ICC and its CI. To address the limitations of current statistical packages, we developed an R package, ICCbin, to facilitate estimating ICC and its CI for binary responses using different methods. The ICCbin package is designed to provide estimates of ICC in 16 different ways including analysis of variance methods, moments based estimation, direct probabilistic methods, correlation based estimation, and resampling method. CI of ICC is estimated using 5 different methods. It also generates cluster binary data using exchangeable correlation structure. ICCbin package provides two functions for users. The function rcbin() generates cluster binary data and the function iccbin() estimates ICC and it's CI. The users can choose appropriate ICC and its CI estimate from the wide selection of estimates from the outputs. The R package ICCbin presents very flexible and easy to use ways to generate cluster binary data and to estimate ICC and it's CI for binary response using different methods. The package ICCbin is freely available for use with R from the CRAN repository (https://cran.r-project.org/package=ICCbin). We believe that this package can be a very useful tool for researchers to design cluster randomized trials with binary outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Theoretical studies of binaries in astrophysics

    Science.gov (United States)

    Dischler, Johann Sebastian

    This thesis introduces and summarizes four papers dealing with computer simulations of astrophysical processes involving binaries. The first part gives the rational and theoretical background to these papers. In paper I and II a statistical approach to studying eclipsing binaries is described. By using population synthesis models for binaries the probabilities for eclipses are calculated for different luminosity classes of binaries. These are compared with Hipparcos data and they agree well if one uses a standard input distribution for the orbit sizes. If one uses a random pairing model, where both companions are independently picked from an IMF, one finds too feclipsing binaries by an order of magnitude. In paper III we investigate a possible scenario for the origin of the stars observed close to the centre of our galaxy, called S stars. We propose that a cluster falls radially cowards the central black hole. The binaries within the cluster can then, if they have small impact parameters, be broken up by the black hole's tidal held and one of the components of the binary will be captured by the black hole. Paper IV investigates how the onset of mass transfer in eccentric binaries depends on the eccentricity. To do this we have developed a new two-phase SPH scheme where very light particles are at tire outer edge of our simulated star. This enables us to get a much better resolution of the very small mass that is transferred in close binaries. Our simulations show that the minimum required distance between the stars to have mass transfer decreases with the eccentricity.

  3. Binary neutron star merger simulations

    Energy Technology Data Exchange (ETDEWEB)

    Bruegmann, Bernd [Jena Univ. (Germany)

    2016-11-01

    Our research focuses on the numerical tools necessary to solve Einstein's equations. In recent years we have been particularly interested in spacetimes consisting of two neutron stars in the final stages of their evolution. Because of the emission of gravitational radiation, the objects are driven together to merge; the emitted gravitational wave signal is visualized. This emitted gravitational radiation carries energy and momentum away from the system and contains information about the system. Late last year the Laser Interferometer Gravitational-wave Observatory (LIGO) began searches for these gravitational wave signals at a sensitivity at which detections are expected. Although such systems can radiate a significant amount of their total mass-energy in gravitational waves, the gravitational wave signals one expects to receive on Earth are not strong, since sources of gravitational waves are often many millions of light years away. Therefore one needs accurate templates for the radiation one expects from such systems in order to be able to extract them out of the detector's noise. Although analytical models exist for compact binary systems when the constituents are well separated, we need numerical simulation to investigate the last orbits before merger to obtain accurate templates and validate analytical approximations. Due to the strong nonlinearity of the equations and the large separation of length scales, these simulations are computationally demanding and need to be run on large supercomputers. When matter is present the computational cost as compared to pure black hole (vacuum) simulations increases even more due to the additional matter fields. But also more interesting astrophysical phenomena can happen. In fact, there is the possibility for a strong electromagnetic signal from the merger (e.g., a short gamma-ray burst or lower-energy electromagnetic signatures from the ejecta) and significant neutrino emission. Additionally, we can expect that

  4. Instabilities in Interacting Binary Stars

    Science.gov (United States)

    Andronov, I. L.; Andrych, K. D.; Antoniuk, K. A.; Baklanov, A. V.; Beringer, P.; Breus, V. V.; Burwitz, V.; Chinarova, L. L.; Chochol, D.; Cook, L. M.; Cook, M.; Dubovský, P.; Godlowski, W.; Hegedüs, T.; Hoňková, K.; Hric, L.; Jeon, Y.-B.; Juryšek, J.; Kim, C.-H.; Kim, Y.; Kim, Y.-H.; Kolesnikov, S. V.; Kudashkina, L. S.; Kusakin, A. V.; Marsakova, V. I.; Mason, P. A.; Mašek, M.; Mishevskiy, N.; Nelson, R. H.; Oksanen, A.; Parimucha, S.; Park, J.-W.; Petrík, K.; Quiñones, C.; Reinsch, K.; Robertson, J. W.; Sergey, I. M.; Szpanko, M.; Tkachenko, M. G.; Tkachuk, L. G.; Traulsen, I.; Tremko, J.; Tsehmeystrenko, V. S.; Yoon, J.-N.; Zola, S.; Shakhovskoy, N. M.

    2017-07-01

    The types of instability in the interacting binary stars are briefly reviewed. The project “Inter-Longitude Astronomy” is a series of smaller projects on concrete stars or groups of stars. It has no special funds, and is supported from resources and grants of participating organizations, when informal working groups are created. This “ILA” project is in some kind similar and complementary to other projects like WET, CBA, UkrVO, VSOLJ, BRNO, MEDUZA, AstroStatistics, where many of us collaborate. Totally we studied 1900+ variable stars of different types, including newly discovered variables. The characteristic timescale is from seconds to decades and (extrapolating) even more. The monitoring of the first star of our sample AM Her was initiated by Prof. V.P. Tsesevich (1907-1983). Since more than 358 ADS papers were published. In this short review, we present some highlights of our photometric and photo-polarimetric monitoring and mathematical modeling of interacting binary stars of different types: classical (AM Her, QQ Vul, V808 Aur = CSS 081231:071126+440405, FL Cet), asynchronous (BY Cam, V1432 Aql), intermediate (V405 Aql, BG CMi, MU Cam, V1343 Her, FO Aqr, AO Psc, RXJ 2123, 2133, 0636, 0704) polars and magnetic dwarf novae (DO Dra) with 25 timescales corresponding to different physical mechanisms and their combinations (part “Polar”); negative and positive superhumpers in nova-like (TT Ari, MV Lyr, V603 Aql, V795 Her) and many dwarf novae stars (“Superhumper”); eclipsing “non-magnetic” cataclysmic variables(BH Lyn, DW UMa, EM Cyg; PX And); symbiotic systems (“Symbiosis”); super-soft sources (SSS, QR And); spotted (and not spotted) eclipsing variables with (and without) evidence for a current mass transfer (“Eclipser”) with a special emphasis on systems with a direct impact of the stream into the gainer star's atmosphere, which we propose to call “Impactor” (short from “Extreme Direct Impactor”), or V361 Lyr-type stars. Other

  5. AUTOMATIC CLASSIFICATION OF VARIABLE STARS IN CATALOGS WITH MISSING DATA

    International Nuclear Information System (INIS)

    Pichara, Karim; Protopapas, Pavlos

    2013-01-01

    We present an automatic classification method for astronomical catalogs with missing data. We use Bayesian networks and a probabilistic graphical model that allows us to perform inference to predict missing values given observed data and dependency relationships between variables. To learn a Bayesian network from incomplete data, we use an iterative algorithm that utilizes sampling methods and expectation maximization to estimate the distributions and probabilistic dependencies of variables from data with missing values. To test our model, we use three catalogs with missing data (SAGE, Two Micron All Sky Survey, and UBVI) and one complete catalog (MACHO). We examine how classification accuracy changes when information from missing data catalogs is included, how our method compares to traditional missing data approaches, and at what computational cost. Integrating these catalogs with missing data, we find that classification of variable objects improves by a few percent and by 15% for quasar detection while keeping the computational cost the same

  6. AUTOMATIC CLASSIFICATION OF VARIABLE STARS IN CATALOGS WITH MISSING DATA

    Energy Technology Data Exchange (ETDEWEB)

    Pichara, Karim [Computer Science Department, Pontificia Universidad Católica de Chile, Santiago (Chile); Protopapas, Pavlos [Institute for Applied Computational Science, Harvard University, Cambridge, MA (United States)

    2013-11-10

    We present an automatic classification method for astronomical catalogs with missing data. We use Bayesian networks and a probabilistic graphical model that allows us to perform inference to predict missing values given observed data and dependency relationships between variables. To learn a Bayesian network from incomplete data, we use an iterative algorithm that utilizes sampling methods and expectation maximization to estimate the distributions and probabilistic dependencies of variables from data with missing values. To test our model, we use three catalogs with missing data (SAGE, Two Micron All Sky Survey, and UBVI) and one complete catalog (MACHO). We examine how classification accuracy changes when information from missing data catalogs is included, how our method compares to traditional missing data approaches, and at what computational cost. Integrating these catalogs with missing data, we find that classification of variable objects improves by a few percent and by 15% for quasar detection while keeping the computational cost the same.

  7. Missing value imputation: with application to handwriting data

    Science.gov (United States)

    Xu, Zhen; Srihari, Sargur N.

    2015-01-01

    Missing values make pattern analysis difficult, particularly with limited available data. In longitudinal research, missing values accumulate, thereby aggravating the problem. Here we consider how to deal with temporal data with missing values in handwriting analysis. In the task of studying development of individuality of handwriting, we encountered the fact that feature values are missing for several individuals at several time instances. Six algorithms, i.e., random imputation, mean imputation, most likely independent value imputation, and three methods based on Bayesian network (static Bayesian network, parameter EM, and structural EM), are compared with children's handwriting data. We evaluate the accuracy and robustness of the algorithms under different ratios of missing data and missing values, and useful conclusions are given. Specifically, static Bayesian network is used for our data which contain around 5% missing data to provide adequate accuracy and low computational cost.

  8. Variance in binary stellar population synthesis

    Science.gov (United States)

    Breivik, Katelyn; Larson, Shane L.

    2016-03-01

    In the years preceding LISA, Milky Way compact binary population simulations can be used to inform the science capabilities of the mission. Galactic population simulation efforts generally focus on high fidelity models that require extensive computational power to produce a single simulated population for each model. Each simulated population represents an incomplete sample of the functions governing compact binary evolution, thus introducing variance from one simulation to another. We present a rapid Monte Carlo population simulation technique that can simulate thousands of populations in less than a week, thus allowing a full exploration of the variance associated with a binary stellar evolution model.

  9. Galactic binaries with eLISA

    OpenAIRE

    Nelemans, G.

    2013-01-01

    I review what eLISA will see from Galactic binaries -- double stars with orbital periods less than a few hours and white dwarf (or neutron star/black hole) components. I discuss the currently known binaries that are guaranteed (or verification) sources and explain why the expected total number of eLISA Galactic binaries is several thousand, even though there are large uncertainties in our knowledge of this population, in particular that of the interacting AM CVn systems. I very briefly sketch...

  10. Past and future implications of near-misses and their emotional consequences.

    Science.gov (United States)

    Zhang, Qiyuan; Covey, Judith

    2014-01-01

    The Reflection and Evaluation Model (REM) of comparative thinking predicts that temporal perspective could moderate people's emotional reactions to close counterfactuals following near-misses (Markman & McMullen, 2003). The experiments reported in this paper tested predictions derived from this theory by examining how people's emotional reactions to a near-miss at goal during a football match (Experiment 1) or a close score in a TV game show (Experiment 2) depended on the level of perceived future possibility. In support of the theory it was found that the presence of future possibility enhanced affective assimilation (e.g., if the near-miss occurred at the beginning of the game the players who had nearly scored were hopeful of future success) whereas the absence of future possibility enhanced affective contrast (e.g., if the near-miss occurred at the end of the game the players who had nearly scored were disappointed about missing an opportunity). Furthermore the experiments built upon our theoretical understanding by exploring the mechanisms which produce assimilation and contrast effects. In Experiment 1 we examined the incidence of present-oriented or future-oriented thinking, and in Experiment 2 we examined the mediating role of counterfactual thinking in the observed effect of proximity on emotions by testing whether stronger counterfactuals (measured using counterfactual probability estimates) produce bigger contrast and assimilation effects. While the results of these investigations generally support the REM, they also highlight the necessity to consider other psychological mechanisms (e.g., social comparison), in addition to counterfactual thinking, that might contribute to the emotional consequences of near-miss outcomes.

  11. Preventing treatment errors in radiotherapy by identifying and evaluating near misses and actual incidents

    LENUS (Irish Health Repository)

    Holmberg, Ola

    2002-06-01

    When preparing radiation treatment, the prescribed dose and irradiation geometry must be translated into physical machine parameters. An error in the calculations or machine settings can negatively affect the intended treatment outcome. Analysing incidents originating in the treatment preparation chain makes it possible to find weak links and prevent treatment errors. The aim of this work is to study the effectiveness of a multilayered error prevention system by analysing both near misses and actual treatment errors.

  12. Sales-marketing interface and company performance. Is information use the missing link?

    OpenAIRE

    Keszey, Tamara

    2013-01-01

    Over the last couple of years there has been an ongoing debate on how sales managers contribute to organizational value. Direct measures between sales-marketing interface quality and company performance are compromised, as company performance is influenced by a plethora of other factors. We advocate that the use of sales information is the missing link between sales-marketing relationship quality and organizational outcomes. We propose and empirically test a model on how sales-mar...

  13. Are We Really Missing Small Galaxies?

    Science.gov (United States)

    Kohler, Susanna

    2018-02-01

    One long-standing astrophysical puzzle is that of so-called missing dwarf galaxies: the number of small dwarf galaxies that we observe is far fewer than that predicted by theory. New simulations, however, suggest that perhaps theres no mystery after all.Missing DwarfsDark-matter cosmological simulations predict many small galaxy halos for every large halo that forms. [The Via Lactea project]Models of a lambda-cold-dark-matter (CDM) universe predict the distribution of galaxy halo sizes throughout the universe, suggesting there should be many more small galaxies than large ones. In what has become known as the missing dwarf problem, however, we find that while we observe the expected numbers of galaxies at the larger end of the scale, we dont see nearly enough small galaxies to match the predictions.Are these galaxies actually missing? Are our predictions wrong? Or are the galaxies there and were just not spotting them? A recent study led by Alyson Brooks (Rutgers University) uses new simulations to explore whatscausing the difference between theory and observation.The fraction of detectable halos as a function of velocity, according to the authors simulations. Below 35 km/s, the detectability of the galaxies drops precipitously. [Brooks et al. 2017]Simulating Galactic VelocitiesBecause we cant weigh a galaxy directly, one proxy used for galaxy mass is its circular velocity; the more massive a galaxy, the faster gas and stars rotate around its center. The discrepancy between models and observations lies in whats known as the galaxy velocity function, which describes the number density of galaxies for a given circular velocity. While theory and observations agree for galaxies with circular velocities above 100 km/s, theory predicts far more dwarfs below this velocity than we observe.To investigate this problem, Brooks and collaborators ran a series of cosmological simulations based on our understanding of a CDM universe. Instead of exploring the result using only

  14. Genders and Individual Treatment Progress in (Non-)Binary Trans Individuals.

    Science.gov (United States)

    Koehler, Andreas; Eyssel, Jana; Nieder, Timo O

    2018-01-01

    Health care for transgender and transsexual (ie, trans) individuals has long been based on a binary understanding of gender (ie, feminine vs masculine). However, the existence of non-binary or genderqueer (NBGQ) genders is increasingly recognized by academic and/or health care professionals. To gain insight into the individual health care experiences and needs of binary and NBGQ individuals to improve their health care outcomes and experience. Data were collected using an online survey study on experiences with trans health care. The non-clinical sample consisted of 415 trans individuals. An individual treatment progress score was calculated to report and compare participants' individual progress toward treatment completion and consider the individual treatment needs and definitions of completed treatment (ie, amount and types of different treatments needed to complete one's medical transition). Main outcome measures were (i) general and trans-related sociodemographic data and (ii) received and planned treatments. Participants reported binary (81.7%) and different NBGQ (18.3%) genders. The 2 groups differed significantly in basic demographic data (eg, mean age; P < .05). NBGQ participants reported significantly fewer received treatments compared with binary participants. For planned treatments, binary participants reported more treatments related to primary sex characteristics only. Binary participants required more treatments for a completed treatment than NBGQ participants (6.0 vs 4.0). There were no differences with regard to individual treatment progress score. Because traditional binary-focused treatment practice could have hindered NBGQ individuals from accessing trans health care or sufficiently articulating their needs, health care professionals are encouraged to provide a holistic and individual treatment approach and acknowledge genders outside the gender binary to address their needs appropriately. Because the study was made inclusive for non

  15. iPod the missing manual

    CERN Document Server

    Biersdorfer, J D

    2008-01-01

    With the tiny Shuffle, the Nano, the Classic, or the Touch, Apple's gotten the world hooked on portable music, pictures, videos -- and the iPod. One thing they haven't delivered is an easy guide for getting the most from this sleek entertainment center. iPod: The Missing Manual, 7th Edition gives you a no-nonsense view of the latest iPod line, with crystal-clear explanations, easy-to-follow color graphics, and guidance on the most useful things your iPod can do.

  16. Switching to the Mac The Missing Manual

    CERN Document Server

    Pogue, David

    2010-01-01

    Is Windows giving you pause? Ready to make the leap to the Mac instead? There has never been a better time to switch from Windows to Mac, and this incomparable guide will help you make a smooth transition. New York Times columnist and Missing Manuals creator David Pogue gets you past three challenges: transferring your stuff, assembling Mac programs so you can do what you did with Windows, and learning your way around Mac OS X. Learning to use a Mac is not a piece of cake, but once you do, the rewards are oh-so-much better. No viruses, worms, or spyware. No questionable firewalls, inefficien

  17. Dreamweaver CS55 The Missing Manual

    CERN Document Server

    McFarland, David

    2011-01-01

    Dreamweaver is the tool most widely used for designing and managing professional-looking websites, but it's a complex program. That's where Dreamweaver CS5.5: The Missing Manual comes in. With its jargon-free explanations, 13 hands-on tutorials, and savvy advice from Dreamweaver expert Dave McFarland, you'll master this versatile program with ease. Get A to Z guidance. Go from building your first web page to creating interactive, database-driven sites.Build skills as you learn. Apply your knowledge through tutorials and downloadable practice files.Create a state-of-the-art website. Use powerf

  18. Handling missing data in ranked set sampling

    CERN Document Server

    Bouza-Herrera, Carlos N

    2013-01-01

    The existence of missing observations is a very important aspect to be considered in the application of survey sampling, for example. In human populations they may be caused by a refusal of some interviewees to give the true value for the variable of interest. Traditionally, simple random sampling is used to select samples. Most statistical models are supported by the use of samples selected by means of this design. In recent decades, an alternative design has started being used, which, in many cases, shows an improvement in terms of accuracy compared with traditional sampling. It is called R

  19. Flash CS5 The Missing Manual

    CERN Document Server

    Grover, Chris

    2010-01-01

    Once you know how to use Flash, you can create everything from simple animations to high-end desktop applications, but it's a complex tool that can be difficult to master on your own-unless you have this Missing Manual. This book will help you learn all you need to know about Flash CS5 to create animations that bring your ideas to life. Learn animation basics. Find everything you need to know to get started with FlashMaster the Flash tools. Learn the animation and effects toolset, with clear explanations and hands-on examplesUse 3D effects. Rotate and put objects in motion in three dimensions

  20. Droid X2 The Missing Manual

    CERN Document Server

    Gralla, Preston

    2011-01-01

    Droid X2 has more power and better graphics than its predecessor, but it still doesn't offer a printed guide to its amazing features. This Missing Manual helps you dig deep into everything Droid X2 can do. Learn how to shop, keep in touch, play with photos, listen to music, and even do some work. Unleash the power of this popular device with expert advice. The important stuff you need to know: Get organized. Sync Droid X2 with Google Calendar, Exchange, and Outlook.Go online. Navigate the Web, use email, and tap into Facebook and Twitter.Listen to tunes. Play and manage music using Droid X2'

  1. Creating a Website The Missing Manual

    CERN Document Server

    MacDonald, Matthew

    2011-01-01

    Think you need an army of skilled programmers to build a website? Think again. With nothing more than an ordinary PC, some raw ambition, and this book, you'll learn how to create and maintain a professional-looking, visitor-friendly site. This Missing Manual gives you all the tools, techniques, and expert advice you need. Plan your site. Create web pages by learning the basics of HTML and HTML5.Control page design with CSS. Format text, images, links, tables, and other elements.Attract visitors. Ensure that people can find your site through popular search engines.Build a community. Add forums

  2. Creating a web site the missing manual

    CERN Document Server

    MacDonald, Matthew

    2008-01-01

    Think you have to be a technical wizard to build a great web site? Think again. If you want to create an engaging web site, this thoroughly revised, completely updated edition of Creating a Web Site: The Missing Manual demystifies the process and provides tools, techniques, and expert guidance for developing a professional and reliable web presence. Whether you want to build a personal web site, an e-commerce site, a blog, or a web site for a specific occasion or promotion, this book gives you detailed instructions and clear-headed advice for: Everything from planning to launching. From pi

  3. Windows Vista for Starters The Missing Manual

    CERN Document Server

    Pogue, David

    2010-01-01

    Fast-paced and easy to use, this concise book teaches you the basics of Windows Vista so you can start using this operating system right away. Written by "New York Times" columnist, bestselling author, Emmy-winning CBS News correspondent and Missing Manuals creator David Pogue, the book will help you: Navigate the desktop, including the fast, powerful and fully integrated desktop search functionUse the Media Center to record TV and radio, present photos, play music, and record all of these to a DVDBreeze across the Web with the vastly improved Internet Explorer 7 tabbed browserBecome familiar

  4. Dixie Valley Bottoming Binary Unit

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Dale [Terra-Gen Sierra Holdings, LLC, Reno, NV (United States)

    2014-12-21

    This binary plant is the first air cooled, high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a hydrocarbon based cycle are not necessary. The unit is largely modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. The Air Cooled Condensers (ACC), equipment piping, and Balance of Plant (BOP) piping were constructed at site. This project further demonstrates the technical feasibility of using low temperature brine for geothermal power utilization. The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.

  5. The symbiotics as binary stars

    International Nuclear Information System (INIS)

    Plavec, M.J.

    1982-01-01

    The author envisages at least three models that can give a symbiotic object: He has called them, respectively, the PN symbiotic, the Algol symbiotic, and the novalike symbiotic. Their properties are briefly discussed. The most promising model is one of a binary system in the second stage of mass transfer, actually at the beginning of it: The cool component is a red giant ascending the asymptotic branch, expanding but not yet filling its critical lobe. The hot star is a subdwarf located in the same region of the Hertzsprung-Russell diagram as the central stars of planetary nebulae. It may be closely related to them, or it may be a helium star, actually a remnant of an Algol primary which underwent the first stage of mass transfer. In these cases, accretion on this star may not play a significant role (PN symbiotic). Perhaps more often, the subdwarf is a ''rejuvenated'' degenerate dwarf whose nuclear burning shells were ignited and are maintained by accretion of material coming from the red giant in the form of a stellar wind. Eruptions are often inevitable: this is the novalike symbiotic. A third alternative is a system in the first stage of mass transfer, where the photons needed for ionization of the nebula come from an accretion disk surrounding a main sequence star: an Algol symbiotic. In spite of considerable observational effort, the symbiotics are known so poorly that it is hard to decide between the models, or even decide if all three can actually exist. (Auth.)

  6. Pulsars in binary systems: probing binary stellar evolution and general relativity.

    Science.gov (United States)

    Stairs, Ingrid H

    2004-04-23

    Radio pulsars in binary orbits often have short millisecond spin periods as a result of mass transfer from their companion stars. They therefore act as very precise, stable, moving clocks that allow us to investigate a large set of otherwise inaccessible astrophysical problems. The orbital parameters derived from high-precision binary pulsar timing provide constraints on binary evolution, characteristics of the binary pulsar population, and the masses of neutron stars with different mass-transfer histories. These binary systems also test gravitational theories, setting strong limits on deviations from general relativity. Surveys for new pulsars yield new binary systems that increase our understanding of all these fields and may open up whole new areas of physics, as most spectacularly evidenced by the recent discovery of an extremely relativistic double-pulsar system.

  7. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    International Nuclear Information System (INIS)

    Haghighipour, Nader; Kaltenegger, Lisa

    2013-01-01

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results

  8. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Haghighipour, Nader [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Kaltenegger, Lisa [MPIA, Koenigstuhl 17, Heidelberg, D-69117 (Germany)

    2013-11-10

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results.

  9. General simulation algorithm for autocorrelated binary processes.

    Science.gov (United States)

    Serinaldi, Francesco; Lombardo, Federico

    2017-02-01

    The apparent ubiquity of binary random processes in physics and many other fields has attracted considerable attention from the modeling community. However, generation of binary sequences with prescribed autocorrelation is a challenging task owing to the discrete nature of the marginal distributions, which makes the application of classical spectral techniques problematic. We show that such methods can effectively be used if we focus on the parent continuous process of beta distributed transition probabilities rather than on the target binary process. This change of paradigm results in a simulation procedure effectively embedding a spectrum-based iterative amplitude-adjusted Fourier transform method devised for continuous processes. The proposed algorithm is fully general, requires minimal assumptions, and can easily simulate binary signals with power-law and exponentially decaying autocorrelation functions corresponding, for instance, to Hurst-Kolmogorov and Markov processes. An application to rainfall intermittency shows that the proposed algorithm can also simulate surrogate data preserving the empirical autocorrelation.

  10. General simulation algorithm for autocorrelated binary processes

    Science.gov (United States)

    Serinaldi, Francesco; Lombardo, Federico

    2017-02-01

    The apparent ubiquity of binary random processes in physics and many other fields has attracted considerable attention from the modeling community. However, generation of binary sequences with prescribed autocorrelation is a challenging task owing to the discrete nature of the marginal distributions, which makes the application of classical spectral techniques problematic. We show that such methods can effectively be used if we focus on the parent continuous process of beta distributed transition probabilities rather than on the target binary process. This change of paradigm results in a simulation procedure effectively embedding a spectrum-based iterative amplitude-adjusted Fourier transform method devised for continuous processes. The proposed algorithm is fully general, requires minimal assumptions, and can easily simulate binary signals with power-law and exponentially decaying autocorrelation functions corresponding, for instance, to Hurst-Kolmogorov and Markov processes. An application to rainfall intermittency shows that the proposed algorithm can also simulate surrogate data preserving the empirical autocorrelation.

  11. Observations of new Wolf-Rayet binaries

    International Nuclear Information System (INIS)

    Niemela, V.S.

    1982-01-01

    The author reports here preliminary results of spectrographic observations for three southern WR stars, whose binary nature had not been previously verified: HDE 320102, CD -45 0 4482, HD 62910. The observations were carried out at the Cerro Tololo Inter-American Observatory, Chile, mostly with the Cassegrain spectrograph with IT attached to the 1-m reflector. These spectrograms were secured on Kodak IIIaJ emulsion, and have a dispersion of 45 A/mm. The results suggest that HDE 320102 must be a double-lined 05-7 + WN3 spectroscopic binary, that CD -45 0 4482 appears to be a single-lined spectroscopic binary and that HD 62910 may be a binary. (Auth.)

  12. Diffusion in ordered binary solid systems

    International Nuclear Information System (INIS)

    Stolwijk, N.A.

    1980-01-01

    This thesis contains contributions to the field of diffusion in ordered binary solid systems. An extensive experimental investigation of the self diffusion in CoGa is presented. The results of these diffusion measurements strongly suggest that a substantial part of the atomic migration is caused by a new type of defect. A quantitative description of the atomic displacements via this defect is given. Finally computer simulations are presented of diffusion and ordering in binary solid systems. (Auth.)

  13. An Introduction to Binary Decision Diagrams

    DEFF Research Database (Denmark)

    Andersen, Henrik Reif

    1996-01-01

    This note is a short introduction to Binary Decision Diagrams (BDDs). It provides some background knowledge and describes the core algorithms. It is used in the course "C4340 Advanced Algorithms" at the Technical University of Denmark, autumn 1996.......This note is a short introduction to Binary Decision Diagrams (BDDs). It provides some background knowledge and describes the core algorithms. It is used in the course "C4340 Advanced Algorithms" at the Technical University of Denmark, autumn 1996....

  14. "Nudge" and the epidemic of missed appointments.

    Science.gov (United States)

    Aggarwal, Ajay; Davies, Joanna; Sullivan, Richard

    2016-06-20

    Purpose - Missed appointments constitute a significant problem in the UK National Health Service (NHS) and this remains an area where improvements could yield substantial efficiency savings. The purpose of this paper is to suggest that nudge policies based on behavioural theories may help target interventions to improve patient motivation to attend appointments. Design/methodology/approach - The authors propose two policies to reduce missed appointments. The first attempts to empower patients through making the appointment system more individualised to them and utilising their intrinsic feelings of social responsibility. The second policy utilises a financial commitment given by the patient at the time of booking. The different mechanisms of influencing patient behaviour are based on two different views of what motivates individuals' actions. The first policy is based on individuals being "knights". They are altruistic and have well-intentioned values. The second policy option is constructed on the premise that an individual is governed by self-interest, and they are in fact "knaves". Findings - A policy, which avoids the use of financial penalties is likely to be more culturally acceptable within the NHS. It could also prevent the phenomenon of "crowding out" whereby the desire to act dutifully gets displaced by the motivation to avoid incurring a monetary fine. Originality/value - Testing both strategies would provide insight into patient attitudes towards health care and society. This would help optimise behavioural strategies which may influence not only appointment attendances but also have wider implications for encouraging rational health care consumption.

  15. Missed lung cancer: when, where, and why?

    Science.gov (United States)

    del Ciello, Annemilia; Franchi, Paola; Contegiacomo, Andrea; Cicchetti, Giuseppe; Bonomo, Lorenzo; Larici, Anna Rita

    2017-01-01

    Missed lung cancer is a source of concern among radiologists and an important medicolegal challenge. In 90% of the cases, errors in diagnosis of lung cancer occur on chest radiographs. It may be challenging for radiologists to distinguish a lung lesion from bones, pulmonary vessels, mediastinal structures, and other complex anatomical structures on chest radiographs. Nevertheless, lung cancer can also be overlooked on computed tomography (CT) scans, regardless of the context, either if a clinical or radiologic suspect exists or for other reasons. Awareness of the possible causes of overlooking a pulmonary lesion can give radiologists a chance to reduce the occurrence of this eventuality. Various factors contribute to a misdiagnosis of lung cancer on chest radiographs and on CT, often very similar in nature to each other. Observer error is the most significant one and comprises scanning error, recognition error, decision-making error, and satisfaction of search. Tumor characteristics such as lesion size, conspicuity, and location are also crucial in this context. Even technical aspects can contribute to the probability of skipping lung cancer, including image quality and patient positioning and movement. Albeit it is hard to remove missed lung cancer completely, strategies to reduce observer error and methods to improve technique and automated detection may be valuable in reducing its likelihood. PMID:28206951

  16. Tidal Dwarf Galaxies and Missing Baryons

    Directory of Open Access Journals (Sweden)

    Frederic Bournaud

    2010-01-01

    Full Text Available Tidal dwarf galaxies form during the interaction, collision, or merger of massive spiral galaxies. They can resemble “normal” dwarf galaxies in terms of mass, size, and become dwarf satellites orbiting around their massive progenitor. They nevertheless keep some signatures from their origin, making them interesting targets for cosmological studies. In particular, they should be free from dark matter from a spheroidal halo. Flat rotation curves and high dynamical masses may then indicate the presence of an unseen component, and constrain the properties of the “missing baryons,” known to exist but not directly observed. The number of dwarf galaxies in the Universe is another cosmological problem for which it is important to ascertain if tidal dwarf galaxies formed frequently at high redshift, when the merger rate was high, and many of them survived until today. In this paper, “dark matter” is used to refer to the nonbaryonic matter, mostly located in large dark halos, that is, CDM in the standard paradigm, and “missing baryons” or “dark baryons” is used to refer to the baryons known to exist but hardly observed at redshift zero, and are a baryonic dark component that is additional to “dark matter”.

  17. Missing baryonic resonances in the Hagedorn spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Man Lo, Pok [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); GSI, Extreme Matter Institute EMMI, Darmstadt (Germany); Marczenko, Michal; Sasaki, Chihiro [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); Redlich, Krzysztof [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); GSI, Extreme Matter Institute EMMI, Darmstadt (Germany); Duke University, Department of Physics, Durham, NC (United States)

    2016-08-15

    The hadronic medium of QCD is modeled as a gas of point-like hadrons, with its composition determined by the Hagedorn mass spectrum. The spectrum consists of a discrete and a continuous part. The former is determined by the experimentally confirmed resonances tabulated by the Particle Data Group (PDG), while the latter can be extracted from the existing lattice data. This formulation of the hadron resonance gas (HRG) provides a transparent framework to relate the fluctuation of conserved charges as calculated in the lattice QCD approach to the particle content of the medium. A comparison of the two approaches shows that the equation of state is well described by the standard HRG model, which includes only a discrete spectrum of known hadrons. The corresponding description in the strange sector, however, shows clear discrepancies, thus a continuous spectrum is added to incorporate the effect of missing resonances. We propose a method to extract the strange-baryon spectrum from the lattice data. The result is consistent with the trend set by the unconfirmed strange baryons resonances listed by the PDG, suggesting that most of the missing interaction strength for the strange baryons reside in the S = 1 sector. This scenario is also supported by recent lattice calculations, and might be important in the energy region covered by the NICA accelerator in Dubna, where in the heavy-ion collisions, baryons are the dominating degrees of freedom in the final state. (orig.)

  18. Missed pills: frequency, reasons, consequences and solutions.

    Science.gov (United States)

    Chabbert-Buffet, Nathalie; Jamin, Christian; Lete, Iñaki; Lobo, Paloma; Nappi, Rossella E; Pintiaux, Axelle; Häusler, Günther; Fiala, Christian

    2017-06-01

    Oral hormonal contraception is an effective contraceptive method as long as regular daily intake is maintained. However, a daily routine is a constraint for many women and can lead to missed pills, pill discontinuation and/or unintended pregnancy. This article describes the frequency of inconsistent use, the consequences, the risk factors and the possible solutions. The article comprises a narrative review of the literature. Forgetting one to three pills per cycle is a frequent problem among 15-51% of users, generally adolescents. The reasons for this are age, inability to establish a routine, pill unavailability, side effects, loss of motivation and lack of involvement in the initial decision to use oral contraceptives. The consequences are 'escape ovulations' and, possibly, unintended pregnancy. Solutions are either to use a long-acting method or, for women who prefer to take oral contraceptives, use a continuous or long-cycle regimen to reduce the risks of follicular development and thus the likelihood of ovulation and unintended pregnancy. A progestogen with a long half-life can increase ovarian suppression. For women deciding to use oral contraceptives, a shortened or eliminated hormone-free interval and a progestogen with a long half-life may be an option to reduce the negative consequences of missed oral contraceptive pills.

  19. Targeted maximum likelihood estimation for a binary treatment: A tutorial.

    Science.gov (United States)

    Luque-Fernandez, Miguel Angel; Schomaker, Michael; Rachet, Bernard; Schnitzer, Mireille E

    2018-04-23

    When estimating the average effect of a binary treatment (or exposure) on an outcome, methods that incorporate propensity scores, the G-formula, or targeted maximum likelihood estimation (TMLE) are preferred over naïve regression approaches, which are biased under misspecification of a parametric outcome model. In contrast propensity score methods require the correct specification of an exposure model. Double-robust methods only require correct specification of either the outcome or the exposure model. Targeted maximum likelihood estimation is a semiparametric double-robust method that improves the chances of correct model specification by allowing for flexible estimation using (nonparametric) machine-learning methods. It therefore requires weaker assumptions than its competitors. We provide a step-by-step guided implementation of TMLE and illustrate it in a realistic scenario based on cancer epidemiology where assumptions about correct model specification and positivity (ie, when a study participant had 0 probability of receiving the treatment) are nearly violated. This article provides a concise and reproducible educational introduction to TMLE for a binary outcome and exposure. The reader should gain sufficient understanding of TMLE from this introductory tutorial to be able to apply the method in practice. Extensive R-code is provided in easy-to-read boxes throughout the article for replicability. Stata users will find a testing implementation of TMLE and additional material in the Appendix S1 and at the following GitHub repository: https://github.com/migariane/SIM-TMLE-tutorial. © 2018 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

  20. Investigator's Guide to Missing Child Cases. For Law-Enforcement Officers Locating Missing Children. Second Edition.

    Science.gov (United States)

    Patterson, John C.

    This booklet provides guidance to law enforcement officers investigating missing children cases, whether through parental kidnappings, abductions by strangers, runaway or "throwaway" cases, and those in which the circumstances are unknown. The guide describes, step-by-step, the investigative process required for each of the four types of missing…

  1. Asteroseismic effects in close binary stars

    Science.gov (United States)

    Springer, Ofer M.; Shaviv, Nir J.

    2013-09-01

    Turbulent processes in the convective envelopes of the Sun and stars have been shown to be a source of internal acoustic excitations. In single stars, acoustic waves having frequencies below a certain cut-off frequency propagate nearly adiabatically and are effectively trapped below the photosphere where they are internally reflected. This reflection essentially occurs where the local wavelength becomes comparable to the pressure scale height. In close binary stars, the sound speed is a constant on equipotentials, while the pressure scale height, which depends on the local effective gravity, varies on equipotentials and may be much greater near the inner Lagrangian point (L1). As a result, waves reaching the vicinity of L1 may propagate unimpeded into low-density regions, where they tend to dissipate quickly due to non-linear and radiative effects. We study the three-dimensional propagation and enhanced damping of such waves inside a set of close binary stellar models using a WKB approximation of the acoustic field. We find that these waves can have much higher damping rates in close binaries, compared to their non-binary counterparts. We also find that the relative distribution of acoustic energy density at the visible surface of close binaries develops a ring-like feature at specific acoustic frequencies and binary separations.

  2. Texture classification by texton: statistical versus binary.

    Directory of Open Access Journals (Sweden)

    Zhenhua Guo

    Full Text Available Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8, image patch (Statistical_Joint and locally invariant fractal (Statistical_Fractal are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor.

  3. Origin of very-short orbital-period binary systems

    International Nuclear Information System (INIS)

    Miyaji, S.

    1983-01-01

    Recent observations of four close binaries have established that there is a group of very-short orbital-period (VSOP) binaries whose orbital periods are less than 60 minutes. The VSOP binaries consist of both X-ray close binaries and cataclysmic variables. Their orbital periods are too short to have a main-sequence companion. However, four binaries, none of which belongs to any globular cluster, are too abundant to be explained by the capturing mechanism of a white dwarf. Therefore it seemed to be worthwhile to present an evolutionary scenario from an original binary system which can be applied for all VSOP binaries. (Auth.)

  4. Connecting traces of galaxy evolution: the missing core mass-morphological fine structure relation

    Science.gov (United States)

    Bonfini, P.; Bitsakis, T.; Zezas, A.; Duc, P.-A.; Iodice, E.; González-Martín, O.; Bruzual, G.; González Sanoja, A. J.

    2018-01-01

    Deep exposure imaging of early-type galaxies (ETGs) are revealing the second-order complexity of these objects, which have been long considered uniform, dispersion-supported spheroidals. `Fine structure' features (e.g. ripples, plumes, tidal tails, rings) as well as depleted stellar cores (i.e. central light deficits) characterize a number of massive ETG galaxies, and can be interpreted as the result of galaxy-galaxy interactions. We discuss how the time-scale for the evolution of cores and fine structures are comparable, and hence it is expected that they develop in parallel after the major interaction event which shaped the ETG. Using archival data, we compare the `depleted stellar mass' (i.e. the mass missing from the depleted stellar core) against the prominence of the fine structure features, and observe that they correlate inversely. This result confirms our expectation that, while the supermassive black hole (SMBH) binary (constituted by the SMBHs of the merger progenitors) excavates the core via three-body interactions, the gravitational potential of the newborn galaxy relaxes, and the fine structures fade below detection levels. We expect the inverse correlation to hold at least within the first Gyr from the merger which created the SMBH binary; after then, the fine structure evolves independently.

  5. Gas dynamics of semidetached binaries

    International Nuclear Information System (INIS)

    Lubow, S.H.; Shu, F.H.

    1975-01-01

    We analyze the gas dynamics of semidetached binary systems within the context of the Rohce model. With the adoption of the assumptions that the contact component rotates synchronously and that the flow occurs isothermally with the thermal speed being a small fraction epsilon of the relative orbital speed, Ωd, of the two stars, we show that the steady flow can be formulated in terms of a problem with multiple length scales. Using this concept, we demonstrate the following by semianalytical methods. (1) The escape of material from the surface of the contact component is accomplished by a highly nonisotropic stellar wind which reaches sonic velocities in a neighborhood of the inner Lagrangian point, L1, of size epsilon in comparison with the orbit separation d. (2) This wind throttles into a narrow stram of material which makes a prescribed angle with respect to the line joining the stellar centers ranging from 19 0 5 to 28 0 4 for the full range of possible stellar mass ratios. (3) The width of the stream scales epsilond while its density scales with epsilon -2 M-dot/Ωd 3 , where M-dot is the mass transfer rate. (4) The stream width remains nearly constant over the part of the stream which is nearly straight, and narrows somewhat as the stream curves toward the detached component. (5) If the detached component is smaller than a certain specified size, the stream results in the formation of a disk of material of prescribed size orbiting the detached component in a direct sense. A subsidi []ry issue examined briefly in this paper is the flow mechanism responsible for moving material to the equator of the contact component, and from there to the L1 region where it is lost by the directed stellar wind. Comparisons of our work are made with previous theoretical studies, and some applications are indicated

  6. What's missing in missing data? Omissions in survey responses among parents of children with advanced cancer.

    Science.gov (United States)

    Rosenberg, Abby R; Dussel, Veronica; Orellana, Liliana; Kang, Tammy; Geyer, J Russel; Feudtner, Chris; Wolfe, Joanne

    2014-08-01

    Missing data is a common phenomenon with survey-based research; patterns of missing data may elucidate why participants decline to answer certain questions. To describe patterns of missing data in the Pediatric Quality of Life and Evaluation of Symptoms Technology (PediQUEST) study, and highlight challenges in asking sensitive research questions. Cross-sectional, survey-based study embedded within a randomized controlled trial. Three large children's hospitals: Dana-Farber/Boston Children's Cancer and Blood Disorders Center (DF/BCCDC); Children's Hospital of Philadelphia (CHOP); and Seattle Children's Hospital (SCH). At the time of their child's enrollment, parents completed the Survey about Caring for Children with Cancer (SCCC), including demographics, perceptions of prognosis, treatment goals, quality of life, and psychological distress. Eighty-six of 104 parents completed surveys (83% response). The proportion of missing data varied by question type. While 14 parents (16%) left demographic fields blank, over half (n=48; 56%) declined to answer at least one question about their child's prognosis, especially life expectancy. The presence of missing data was unrelated to the child's diagnosis, time from progression, time to death, or parent distress (p>0.3 for each). Written explanations in survey margins suggested that addressing a child's life expectancy is particularly challenging for parents. Parents of children with cancer commonly refrain from answering questions about their child's prognosis, however, they may be more likely to address general cure likelihood than explicit life expectancy. Understanding acceptability of sensitive questions in survey-based research will foster higher quality palliative care research.

  7. Treatments of Missing Values in Large National Data Affect Conclusions: The Impact of Multiple Imputation on Arthroplasty Research.

    Science.gov (United States)

    Ondeck, Nathaniel T; Fu, Michael C; Skrip, Laura A; McLynn, Ryan P; Su, Edwin P; Grauer, Jonathan N

    2018-03-01

    Despite the advantages of large, national datasets, one continuing concern is missing data values. Complete case analysis, where only cases with complete data are analyzed, is commonly used rather than more statistically rigorous approaches such as multiple imputation. This study characterizes the potential selection bias introduced using complete case analysis and compares the results of common regressions using both techniques following unicompartmental knee arthroplasty. Patients undergoing unicompartmental knee arthroplasty were extracted from the 2005 to 2015 National Surgical Quality Improvement Program. As examples, the demographics of patients with and without missing preoperative albumin and hematocrit values were compared. Missing data were then treated with both complete case analysis and multiple imputation (an approach that reproduces the variation and associations that would have been present in a full dataset) and the conclusions of common regressions for adverse outcomes were compared. A total of 6117 patients were included, of which 56.7% were missing at least one value. Younger, female, and healthier patients were more likely to have missing preoperative albumin and hematocrit values. The use of complete case analysis removed 3467 patients from the study in comparison with multiple imputation which included all 6117 patients. The 2 methods of handling missing values led to differing associations of low preoperative laboratory values with commonly studied adverse outcomes. The use of complete case analysis can introduce selection bias and may lead to different conclusions in comparison with the statistically rigorous multiple imputation approach. Joint surgeons should consider the methods of handling missing values when interpreting arthroplasty research. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The History of Miss Jane Pittman

    Directory of Open Access Journals (Sweden)

    Christopher Mulvey

    2006-05-01

    Full Text Available This paper explores the ways in which Ernest J. Gaines uses fiction in The Autobiography of Miss Jane Pittman to write a history of the African American from 1861 to 1961. The “Introduction” sets the novel going, but its direction has already been given in the unusual dedication to his grandmother, stepfather and aunt “who did not walk a day in her life but who taught me the importance of standing” (Gaines iv. The significance for Gaines is that what happened a hundred years ago is part of his present-day lived life.The nineteenth-century novel was possessed by history, and white nineteenth-century novelists found their great subject in the war of European nations that was fought between 1799 and 1815. But that was not an American war nor was it an African American war. For Gaines, the war that makes the great turning point of a nation and a people is the American Civil War, fought from 1861 to 1865. It resulted in a moment of history after which life would not be the same. However, one of the main points that Gaines makes about that great turning point in history is that everything changed and nothing changed. And his main fictional device to establish that truth is to tell the history of the hundred years since Emancipation as the story of one woman. Her autobiography becomes an ethno-biography.The continuity forwards from 1861 is given through the life of one woman, but Gaines’s uses another device to provide a continuity backwards from 1861. The young man who wants to get Miss Jane Pittman’s story upsets her with his persistence: “What you want know about Miss Jane for?’ Mary said. ‘I teach history,’ I said. ‘I’m sure her life’s story can help me explain things to my students.’ ‘What’s wrong with them books you already got?’ Mary said. ‘Miss Jane is not in them,’ I said” (Gaines v. Ernest J. Gaines wrote at a time when historians finally began to recognize that they could get no true history of the

  9. Evaluation of missing value methods for predicting ambient BTEX concentrations in two neighbouring cities in Southwestern Ontario Canada

    Science.gov (United States)

    Miller, Lindsay; Xu, Xiaohong; Wheeler, Amanda; Zhang, Tianchu; Hamadani, Mariam; Ejaz, Unam

    2018-05-01

    High density air monitoring campaigns provide spatial patterns of pollutant concentrations which are integral in exposure assessment. Such analysis can assist with the determination of links between air quality and health outcomes, however, problems due to missing data can threaten to compromise these studies. This research evaluates four methods; mean value imputation, inverse distance weighting (IDW), inter-species ratios, and regression, to address missing spatial concentration data ranging from one missing data point up to 50% missing data. BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations were measured in Windsor and Sarnia, Ontario in the fall of 2005. Concentrations and inter-species ratios were generally similar between the two cities. Benzene (B) was observed to be higher in Sarnia, whereas toluene (T) and the T/B ratios were higher in Windsor. Using these urban, industrialized cities as case studies, this research demonstrates that using inter-species ratios or regression of the data for which there is complete information, along with one measured concentration (i.e. benzene) to predict for missing concentrations (i.e. TEX) results in good agreement between predicted and measured values. In both cities, the general trend remains that best agreement is observed for the leave-one-out scenario, followed by 10% and 25% missing, and the least agreement for the 50% missing cases. In the absence of any known concentrations IDW can provide reasonable agreement between observed and estimated concentrations for the BTEX species, and was superior over mean value imputation which was not able to preserve the spatial trend. The proposed methods can be used to fill in missing data, while preserving the general characteristics and rank order of the data which are sufficient for epidemiologic studies.

  10. Binaries and triples among asteroid pairs

    Science.gov (United States)

    Pravec, Petr; Scheirich, Peter; Kušnirák, Peter; Hornoch, Kamil; Galád, Adrián

    2015-08-01

    Despite major achievements obtained during the past two decades, our knowledge of the population and properties of small binary and multiple asteroid systems is still far from advanced. There is a numerous indirect evidence for that most small asteroid systems were formed by rotational fission of cohesionless parent asteroids that were spun up to the critical frequency presumably by YORP, but details of the process are lacking. Furthermore, as we proceed with observations of more and more binary and paired asteroids, we reveal new facts that substantially refine and sometimes change our understanding of the asteroid systems. One significant new finding we have recently obtained is that primaries of many asteroid pairs are actually binary or triple systems. The first such case found is (3749) Balam (Vokrouhlický, ApJL 706, L37, 2009). We have found 9 more binary systems among asteroid pairs within our ongoing NEOSource photometric project since October 2012. They are (6369) 1983 UC, (8306) Shoko, (9783) Tensho-kan, (10123) Fideoja, (21436) Chaoyichi, (43008) 1999 UD31, (44620) 1999 RS43, (46829) 1998 OS14 and (80218) 1999 VO123. We will review their characteristics. These paired binaries as we call them are mostly similar to binaries in the general ("background") population (of unpaired asteroids), but there are a few trends. The paired binaries tend to have larger secondaries with D_2/D_1 = 0.3 to 0.5 and they also tend to be wider systems with 8 of the 10 having orbital periods between 30 and 81 hours, than average among binaries in the general population. There may be also a larger fraction of triples; (3749) Balam is a confirmed triple, having a larger close and a smaller distant satellite, and (8306) Shoko and (10123) Fideoja are suspect triples as they show additional rotational lightcurve components with periods of 61 and 38.8 h that differ from the orbital period of 36.2 and 56.5 h, respectively. The unbound secondaries tend to be of the same size or

  11. Close-binary central stars of planetary nebulae

    International Nuclear Information System (INIS)

    Bond, H.E.; Grauer, A.D.

    1987-01-01

    Recent observations of PN central stars identified as binary systems are reviewed. The theoretical significance of binary central stars is discussed, and the characteristics of UU Sge, V 477 Lyr, MT Ser, LSS 2018, VW Pyx, and the central star of HFG 1 are briefly summarized. All of these binaries are shown to have periods less than 1 day, and it is estimated that about 10 percent of all binary central stars are close binaries. 27 references

  12. Missing transverse energy performance of the CMS detector

    Energy Technology Data Exchange (ETDEWEB)

    Chatrchyan, Serguei [Yerevan Physics Inst. (Armenia); et al.

    2011-09-01

    During 2010 the LHC delivered pp collisions with a centre-of-mass energy of 7 TeV. In this paper, the results of comprehensive studies of missing transverse energy as measured by the CMS detector are presented. The results cover the measurements of the scale and resolution for missing transverse energy, and the effects of multiple pp interactions within the same bunch crossings on the scale and resolution. Anomalous measurements of missing transverse energy are studied, and algorithms for their identification are described. The performances of several reconstruction algorithms for calculating missing transverse energy are compared. An algorithm, called missing-transverse-energy significance, which estimates the compatibility of the reconstructed missing transverse energy with zero, is described, and its performance is demonstrated.

  13. Missing transverse energy performance of the CMS detector

    International Nuclear Information System (INIS)

    2011-01-01

    During 2010 the LHC delivered pp collisions with a centre-of-mass energy of 7 TeV. In this paper, the results of comprehensive studies of missing transverse energy as measured by the CMS detector are presented. The results cover the measurements of the scale and resolution for missing transverse energy, and the effects of multiple pp interactions within the same bunch crossings on the scale and resolution. Anomalous measurements of missing transverse energy are studied, and algorithms for their identification are described. The performance of several reconstruction algorithms for calculating missing transverse energy are compared. An algorithm, called missing-transverse-energy significance, which estimates the compatibility of the reconstructed missing transverse energy with zero, is described, and its performance is demonstrated.

  14. Reducing Competitive Cache Misses in Modern Processor Architectures

    OpenAIRE

    Prisagjanec, Milcho; Mitrevski, Pece

    2017-01-01

    The increasing number of threads inside the cores of a multicore processor, and competitive access to the shared cache memory, become the main reasons for an increased number of competitive cache misses and performance decline. Inevitably, the development of modern processor architectures leads to an increased number of cache misses. In this paper, we make an attempt to implement a technique for decreasing the number of competitive cache misses in the first level of cache memory. This tec...

  15. Impact of teamwork on missed care in four Australian hospitals.

    Science.gov (United States)

    Chapman, Rose; Rahman, Asheq; Courtney, Mary; Chalmers, Cheyne

    2017-01-01

    Investigate effects of teamwork on missed nursing care across a healthcare network in Australia. Missed care is universally used as an indicator of quality nursing care, however, little is known about mitigating effects of teamwork on these events. A descriptive exploratory study. Missed Care and Team Work surveys were completed by 334 nurses. Using Stata software, nursing staff demographic information and components of missed care and teamwork were compared across the healthcare network. Statistical tests were performed to identify predicting factors for missed care. The most commonly reported components of missed care were as follows: ambulation three times per day (43·3%), turning patient every two hours (29%) and mouth care (27·7%). The commonest reasons mentioned for missed care were as follows: inadequate labour resources (range 69·8-52·7%), followed by material resources (range 59·3-33·3%) and communication (range 39·3-27·2%). There were significant differences in missed care scores across units. Using the mean scores in regression correlation matrix, the negative relationship of missed care and teamwork was supported (r = -0·34, p teamwork alone accounted for about 9% of missed nursing care. Similar to previous international research findings, our results showed nursing teamwork significantly impacted on missed nursing care. Teamwork may be a mitigating factor to address missed care and future research is needed. These results may provide administrators, educators and clinicians with information to develop practices and policies to improve patient care internationally. © 2016 John Wiley & Sons Ltd.

  16. iPod The Missing Manual

    CERN Document Server

    Biersdorfer, J D

    2010-01-01

    With iPod and iTunes, Apple's gotten the world hooked on portable music, pictures, and videos. One thing they haven't delivered, though, is an easy guide for getting the most from your sleek little entertainment center. Enter iPod: The Missing Manual, 5th Edition-a book as breathtaking and satisfying as its subject. Our latest edition thoroughly covers the redesigned iPod Nanos, the video iPod, the tiny Shuffle and the overhauled iTunes 7. Each custom-designed page sports easy-to-follow color graphics, crystal-clear explanations, and guidance on the most useful things your iPod can do. Topic

  17. Bladder injuries frequently missed in polytrauma patients

    Directory of Open Access Journals (Sweden)

    Tanweer Karim

    2010-05-01

    Full Text Available Tanweer Karim, Margaret Topno, Vinod Sharma, Raymond Picardo, Ankur HastirSurgery, MGM Medical College, Kamothe, Navi Mumbai, IndiaAbstract: Bladder injuries are very common in patients who have had road traffic accidents. The method of diagnosis and management of such injuries is well established and accepted. However, trauma to the bladder can be associated with other life-threatening injuries which are frequently missed, and often diagnosed during laparotomy for other reasons. The aim of this study was to diagnose bladder injury in polytrauma patients as early as possible, taking into consideration the fact that these patients are hemodynamically unstable and require rapid evaluation and management. In order to achieve our objective, we used bedside sonography with retrograde instillation of normal saline to diagnose bladder injury in addition to use of the conventional retrograde cystogram.Keywords: bladder injury, bladder rupture, retrograde cystogram

  18. iPad The Missing Manual

    CERN Document Server

    Biersdorfer, J

    2010-01-01

    The iPad 2 is faster, lighter, and more versatile than its predecessor, but there's still no printed guide to using its amazing features. That's where this full-color Missing Manual comes in. Learn how to stream HD video, make video calls, manage your email, surf the Web, listen to music, play games, and maybe even do a little iWork. This is the book that should have been in the box. Build your media library. Fill your iPad with music, movies, TV shows, eBooks, photos, and more.Share with others. Stream music, HD movies, TV shows, and more, to and from your iPad.Create your own media. Use the

  19. iPad 2 The Missing Manual

    CERN Document Server

    Biersdorfer, JD

    2011-01-01

    With iOS 5, Apple added more than 200 new features to the iPad 2, but there's still no printed guide to using all its amazing capabilities. That's where this full-color Missing Manual comes in. You'll learn how to stuff your iPad with media, organize your personal life, wirelessly stream content to and from your tablet, stay connected to friends, and much more. The important stuff you need to know: Build your media library. Fill your iPad with music, movies, TV shows, eBooks, eMagazines, photos, and more.Go wireless. Sync content between your computer and iPad-no wires needed.Get online. Con

  20. Missing IUD Despite Threads at the Cervix

    Directory of Open Access Journals (Sweden)

    Andrew L. Atkinson

    2014-01-01

    Full Text Available Today, the intrauterine device (IUD is by far the most popular form of long term reversible contraception in the world. Side effects from the IUD are minimal and complications are rare. Uterine perforation and migration of the IUD outside the uterine cavity are the most serious complications. Physician visualization and/or the patient feeling retrieval threads at the cervical os are confirmation that the IUD has not been expelled or migrated. We present a case of a perforated, intraperitoneal IUD with threads noted at the cervical os. Office removal was not possible using gentle traction on the threads. Multiple imaging and endoscopic modalities were used to try and locate the IUD including pelvic ultrasound, diagnostic hysteroscopy, cystoscopy, and pelvic magnetic resonance imaging (MRI. The studies gave conflicting results on location of the IUD. Ultimately, the missing IUD was removed via laparoscopy.

  1. iPod The Missing Manual

    CERN Document Server

    Biersdorfer, J D

    2011-01-01

    Apple's iPod still has the world hooked on portable music, pictures, videos, movies, and more, but one thing it doesn't have is a manual that helps you can get the most out this amazing device. That's where this book comes in. Get the complete scoop on the latest line of iPods and the latest version of iTunes with the guide that outshines them all-iPod: The Missing Manual. The 10th edition is as useful, satisfying, and reliable as its subject. Teeming with high-quality color graphics, each page helps you accomplish a specific task-everything from managing your media and installing and browsi

  2. Interventions for replacing missing teeth: partially absent dentition.

    Science.gov (United States)

    Abt, Elliot; Carr, Alan B; Worthington, Helen V

    2012-02-15

    Management of individuals presenting with partial loss of teeth is a common task for dentists. Outcomes important to the management of missing teeth in the partially absent dentition should be systematically summarized. This review recognizes both the challenges associated with such a summarization and the critical nature of the information for patients. To assess the effects of different prostheses for the treatment of partially absent dentition in terms of the following outcomes: long-term success, function, morbidity and patient satisfaction. We searched the Cochrane Oral Health Group's Trials Register (to 21 March 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), MEDLINE via OVID (1950 to March 2011) and EMBASE via OVID (1980 to March 2011). There were no restrictions regarding language or date of publication. We contacted several authors to identify non-published trials. Randomized controlled trials (RCTs) comparing different methods (including the design and materials used) of treating partial edentulism, with clinically relevant outcomes, were included in this review. Trials reporting only surrogate outcomes, such as plaque accumulation or gingival volume, were excluded from this review. Two review authors independently carried out the screening of eligible studies, assessment of dimensions of quality of trials, and data extraction. Results were expressed as mean differences for continuous data, risk ratios for dichotomous outcomes, and hazard ratios with 95% confidence intervals for time-to-event data. Twenty-one trials met the inclusion criteria for this review. Twenty-four per cent of these were assessed as being at high risk of bias and the remainder were at unclear risk of bias. The clinical heterogeneity among the included studies precluded any attempt at meta-analysis. There was insufficient evidence to determine whether one type of removable dental prosthesis (RDP) was better or worse than

  3. The missing mass of the universe

    International Nuclear Information System (INIS)

    Lachieze-Rey, M.

    2002-01-01

    The existence of dark matter is suggested by 2 facts: 1) the real mass of matter inside galaxies must be 10 times greater than the observed mass to explain the values of the spinning velocity of galaxies around their centers. Furthermore the value of this velocity does not depend a lot on the distance to the center of the galaxy, this implies that the missing mass is uniformly distributed inside galaxies; 2) According to general relativity, massive celestial bodies produce a curvature of space-time that generates a deviation of light beams. These deviations have been studied and it appears that they require the presence of a far more important quantity of matter than the quantity reduced to visible matter. The missing mass issue arises 3 problems, the first problem comes from the existence of a great part of ordinary (baryonic) matter that is invisible: the global mass of stars represents only 10 % of the total baryonic mass of the universe. This invisible ordinary matter might exist in condensed form in black-hole, giant planets or brown dwarfs roaming the galaxies. The second problem arose when most scientists were convinced of the existence of huge quantity of non-baryonic matter, 10 times more abundant than the baryonic matter. The supersymmetric extension of the standard model allows the existence of particles that might be candidate for carrying this non-baryonic mass. The third problem appeared recently when measurement of the curvature of the space-time has shown that the 3 forms of matter: visible matter, invisible ordinary matter and non-baryonic matter contribute together to only one third of the total energy of the universe. (A.C.)

  4. Missed Opportunities For Immunization In Children And Pregnant Women

    Directory of Open Access Journals (Sweden)

    Benjamin A I

    1990-01-01

    Full Text Available The role of immunization in reducing childhood mortality cannot be over-emphasised, yet many opportunities for immunization are missed when children and pregnant women visit a health facility. Reducing missed opportunities is the cheapest way to increase immunization coverage. The present study discusses the extent of the problem of missed opportunities for immunization in children and pregnant women and the factors contributing to the problem, in spatiality and community outreach clinics of Christian Medical College & Hospital, Ludhiana. Recommendations are made regarding ways and means of reducing missed opportunities.

  5. Social perspective: the missing element in mental health practice

    National Research Council Canada - National Science Library

    U'Ren, Richard C

    2011-01-01

    .... ________________________________________________________________ Library and Archives Canada Cataloguing in Publication U'Ren, Richard, 1939- Social perspective : the missing element in mental health practice / Richard U'Ren...

  6. The WHO maternal near-miss approach and the maternal severity index model (MSI: tools for assessing the management of severe maternal morbidity.

    Directory of Open Access Journals (Sweden)

    Joao Paulo Souza

    Full Text Available OBJECTIVES: To validate the WHO maternal near-miss criteria and develop a benchmark tool for severe maternal morbidity assessments. METHODS: In a multicenter cross-sectional study implemented in 27 referral maternity hospitals in Brazil, a one-year prospective surveillance on severe maternal morbidity and data collection was carried out. Diagnostic accuracy tests were used to assess the validity of the WHO maternal near-miss criteria. Binary logistic regression was used to model the death probability among women with severe maternal complications and benchmark the management of severe maternal morbidity. RESULTS: Of the 82,388 women having deliveries in the participating health facilities, 9,555 women presented pregnancy-related complications, including 140 maternal deaths and 770 maternal near misses. The WHO maternal near-miss criteria were found to be accurate and highly associated with maternal deaths (Positive likelihood ratio 106.8 (95% CI 99.56-114.6. The maternal severity index (MSI model was developed and found to able to describe the relationship between life-threatening conditions and mortality (Area under the ROC curve: 0.951 (95% CI 0.909-0.993. CONCLUSION: The identification of maternal near-miss cases using the WHO list of pregnancy-related life-threatening conditions was validated. The MSI model can be used as a tool for benchmarking the performance of health services managing women with severe maternal complications and provide case-mix adjustment.

  7. Do stellar clusters form fewer binaries? Using moderate separation binaries to distinguish between nature and nurture

    Science.gov (United States)

    Reiter, Megan

    2017-08-01

    Fewer wide-separation binaries are found in dense stellar clusters than in looser stellar associations. It is therefore unclear whether feedback in clusters prevents the formation of multiple systems or dynamical interactions destroy them. Measuring the prevalence of close, bound binary systems provide a key test to distinguish between these possibilities. Systems with separations of 10-50 AU will survive interactions in the cluster environment, and therefore are more representative of the natal population of multiple systems. By fitting a double-star PSF, we will identify visual binaries in the Orion Nebula with separations as small as 0.03. At the distance of Orion, this corresponds to a physical separation of 12 AU, effectively closing the observational gap in the binary separation distribution left between known visual and spectroscopic binaries (>65 AU or PhD thesis.

  8. Serial binary interval ratios improve rhythm reproduction.

    Science.gov (United States)

    Wu, Xiang; Westanmo, Anders; Zhou, Liang; Pan, Junhao

    2013-01-01

    Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8), non-binary integer (1:3:5:6), and non-integer (1:2.3:5.3:6.4) ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

  9. Serial binary interval ratios improve rhythm reproduction

    Directory of Open Access Journals (Sweden)

    Xiang eWu

    2013-08-01

    Full Text Available Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8, non-binary integer (1:3:5:6, and non-integer (1:2.3:5.3:6.4 ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

  10. Beyond binaries : a way forward for comparativeeducation

    Directory of Open Access Journals (Sweden)

    Marianne Larsen

    2012-09-01

    Full Text Available Binary discourses shape and produce the stories we construct about the field of comparative education. In the first part of this article, I review a set of binary discourses that have characterized social science research since the Enlightenment, including: quantitative-qualitative, nomotheticidiographic, inductive-deductive, and practice-theory. We can think of each of these binaries at opposite ends of a set of spectrums. In the second section of the paper, I show some of the ways in which these binaries have influenced the ways that we write and talk about research within the field of comparative education. I refer to the notion of binary discourses and the productive capacity of these discourses to shape our field. I then outline some critiques of these binaries to demonstrate the inherent limitations of binary discourses, and why we need to move beyond binaries in our research, and in the histories about our field. Finally, I present some tentative conclusions on ways to get ourselves out of the trap of binary thinking.Los discursos binarios moldean y producen los argumentos que construimos sobre la disciplina de la Educación Comparada. En la primera parte de este artículo, analizo un conjunto de discursos binarios que han caracterizado la investigación en Ciencias Sociales desde la Ilustración, incluyendo la cuantitativa-cualitativa, nomotética-idiográfica, inductivadeductiva, y la práctica-teoría. Podemos pensar sobre cada uno de estos discursos binarios como argumentos en los polos de un conjunto de posibilidades. En la segunda sección del artículo, revelo algunos modos en los que estos discursos binarios han influenciado las formas a través de las cuales escribimos y analizamos la investigación en el ámbito de la Educación Comparada. Analizo la noción de discursos binarios y la capacidad productiva de estos discursos de impactar nuestra ciencia. Seguidamente expongo algunas críticas de estos discursos binarios con el

  11. Comparison of the binary logistic and skewed logistic (Scobit) models of injury severity in motor vehicle collisions.

    Science.gov (United States)

    Tay, Richard

    2016-03-01

    The binary logistic model has been extensively used to analyze traffic collision and injury data where the outcome of interest has two categories. However, the assumption of a symmetric distribution may not be a desirable property in some cases, especially when there is a significant imbalance in the two categories of outcome. This study compares the standard binary logistic model with the skewed logistic model in two cases in which the symmetry assumption is violated in one but not the other case. The differences in the estimates, and thus the marginal effects obtained, are significant when the assumption of symmetry is violated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The binary white dwarf LHS 3236

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Hugh C.; Dahn, Conard C.; Canzian, Blaise; Guetter, Harry H.; Levine, Stephen E.; Luginbuhl, Christian B.; Monet, Alice K. B.; Stone, Ronald C.; Subasavage, John P.; Tilleman, Trudy; Walker, Richard L. [US Naval Observatory, 10391 West Naval Observatory Road, Flagstaff, AZ 86001-8521 (United States); Dupuy, Trent J.; Liu, Michael C. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hartkopf, William I. [US Naval Observatory, 3450 Massachusetts Avenue, N.W., Washington, DC 20392-5420 (United States); Ireland, Michael J. [Department of Physics and Astronomy, Macquarie University, New South Wales, NSW 2109 (Australia); Leggett, S. K., E-mail: hch@nofs.navy.mil [Gemini Observatory, 670 N. Aohoku Place, Hilo, HI 96720 (United States)

    2013-12-10

    The white dwarf LHS 3236 (WD1639+153) is shown to be a double-degenerate binary, with each component having a high mass. Astrometry at the U.S. Naval Observatory gives a parallax and distance of 30.86 ± 0.25 pc and a tangential velocity of 98 km s{sup –1}, and reveals binary orbital motion. The orbital parameters are determined from astrometry of the photocenter over more than three orbits of the 4.0 yr period. High-resolution imaging at the Keck Observatory resolves the pair with a separation of 31 and 124 mas at two epochs. Optical and near-IR photometry give a set of possible binary components. Consistency of all data indicates that the binary is a pair of DA stars with temperatures near 8000 and 7400 K and with masses of 0.93 and 0.91 M {sub ☉}; also possible is a DA primary and a helium DC secondary with temperatures near 8800 and 6000 K and with masses of 0.98 and 0.69 M {sub ☉}. In either case, the cooling ages of the stars are ∼3 Gyr and the total ages are <4 Gyr. The combined mass of the binary (1.66-1.84 M {sub ☉}) is well above the Chandrasekhar limit; however, the timescale for coalescence is long.

  13. Investigating Dark Energy with Black Hole Binaries

    International Nuclear Information System (INIS)

    Mersini-Houghton, Laura; Kelleher, Adam

    2009-01-01

    The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accrete dark energy. The accretion induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state w[z] of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. This talk describes how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy.

  14. Star formation history: Modeling of visual binaries

    Science.gov (United States)

    Gebrehiwot, Y. M.; Tessema, S. B.; Malkov, O. Yu.; Kovaleva, D. A.; Sytov, A. Yu.; Tutukov, A. V.

    2018-05-01

    Most stars form in binary or multiple systems. Their evolution is defined by masses of components, orbital separation and eccentricity. In order to understand star formation and evolutionary processes, it is vital to find distributions of physical parameters of binaries. We have carried out Monte Carlo simulations in which we simulate different pairing scenarios: random pairing, primary-constrained pairing, split-core pairing, and total and primary pairing in order to get distributions of binaries over physical parameters at birth. Next, for comparison with observations, we account for stellar evolution and selection effects. Brightness, radius, temperature, and other parameters of components are assigned or calculated according to approximate relations for stars in different evolutionary stages (main-sequence stars, red giants, white dwarfs, relativistic objects). Evolutionary stage is defined as a function of system age and component masses. We compare our results with the observed IMF, binarity rate, and binary mass-ratio distributions for field visual binaries to find initial distributions and pairing scenarios that produce observed distributions.

  15. [Missed lessons, missed opportunities: a role for public health services in medical absenteeism in young people].

    Science.gov (United States)

    Vanneste, Y T M; van de Goor, L A M; Feron, F J M

    2016-01-01

    Young people who often miss school for health reasons are not only missing education, but also the daily routine of school, and social intercourse with their classmates. Medical absenteeism among students merits greater attention. For a number of years, in various regions in the Netherlands, students with extensive medical absenteeism have been invited to see a youth healthcare specialist. The MASS intervention (Medical Advice of Students reported Sick; in Dutch: Medische Advisering van de Ziekgemelde Leerling, abbreviated as M@ZL) has been developed by the West Brabant Regional Public Health Service together with secondary schools to address school absenteeism due to reporting sick. In this paper we discuss the MASS intervention and explain why attention should be paid by public health services to the problem of school absenteeism, especially absenteeism on health grounds.

  16. Social and Emotional Wellbeing Screening for Aboriginal and Torres Strait Islanders within Primary Health Care: A Series of Missed Opportunities?

    Directory of Open Access Journals (Sweden)

    Erika Langham

    2017-07-01

    Full Text Available BackgroundSocial and emotional wellbeing (SEWB is a critical determinant of health outcomes for Indigenous Australians. This study examined the extent to which primary healthcare services (PHSs undertake SEWB screening and management of Aboriginal and Torres Strait Islander clients, and the variation in SEWB screening and management across Indigenous PHS.MethodsCross-sectional analysis between 2012 and 2014 of 3,407 Indigenous client records from a non-representative sample of 100 PHSs in 4 Australian states/territory was undertaken to examine variation in the documentation of: (1 SEWB screening using identified measurement instruments, (2 concern regarding SEWB, (3 actions in response to concern, and (4 follow up actions. Binary logistic regression was used to determine the factors associated with screening.ResultsThe largest variation in SEWB screening occurred at the state/territory level. The mean rate of screening across the sample was 26.6%, ranging from 13.7 to 37.1%. Variation was also related to PHS characteristics. A mean prevalence of identified SEWB concern was 13% across the sample, ranging from 9 to 45.1%. For the clients where SEWB concern was noted, 25.4% had no referral or PHS action recorded. Subsequent internal PHS follow up after 1 month occurred in 54.7% of cases; and six-monthly follow up of referrals to external services occurred in 50.9% of cases.ConclusionOur findings suggest that the lack of a clear model or set of guidelines on best practice for screening for SEWB in Indigenous health may contribute to the wide variation in SEWB service provision. The results tell a story of missed opportunities: 73.4% of clients were not screened and no further action was taken for 25.4% for whom an SEWB concern was identified. There was no follow up for just under half of those for whom action was taken. There is a need for the development of national best practice guidelines for SEWB screening and management, accompanied by

  17. Social and Emotional Wellbeing Screening for Aboriginal and Torres Strait Islanders within Primary Health Care: A Series of Missed Opportunities?

    Science.gov (United States)

    Langham, Erika; McCalman, Janya; Matthews, Veronica; Bainbridge, Roxanne Gwendalyn; Nattabi, Barbara; Kinchin, Irina; Bailie, Ross

    2017-01-01

    Social and emotional wellbeing (SEWB) is a critical determinant of health outcomes for Indigenous Australians. This study examined the extent to which primary healthcare services (PHSs) undertake SEWB screening and management of Aboriginal and Torres Strait Islander clients, and the variation in SEWB screening and management across Indigenous PHS. Cross-sectional analysis between 2012 and 2014 of 3,407 Indigenous client records from a non-representative sample of 100 PHSs in 4 Australian states/territory was undertaken to examine variation in the documentation of: (1) SEWB screening using identified measurement instruments, (2) concern regarding SEWB, (3) actions in response to concern, and (4) follow up actions. Binary logistic regression was used to determine the factors associated with screening. The largest variation in SEWB screening occurred at the state/territory level. The mean rate of screening across the sample was 26.6%, ranging from 13.7 to 37.1%. Variation was also related to PHS characteristics. A mean prevalence of identified SEWB concern was 13% across the sample, ranging from 9 to 45.1%. For the clients where SEWB concern was noted, 25.4% had no referral or PHS action recorded. Subsequent internal PHS follow up after 1 month occurred in 54.7% of cases; and six-monthly follow up of referrals to external services occurred in 50.9% of cases. Our findings suggest that the lack of a clear model or set of guidelines on best practice for screening for SEWB in Indigenous health may contribute to the wide variation in SEWB service provision. The results tell a story of missed opportunities: 73.4% of clients were not screened and no further action was taken for 25.4% for whom an SEWB concern was identified. There was no follow up for just under half of those for whom action was taken. There is a need for the development of national best practice guidelines for SEWB screening and management, accompanied by dedicated SEWB funding, and training for health

  18. STUDY ON MATERNAL MORTALITY AND NEAR MISS CASE

    Directory of Open Access Journals (Sweden)

    Ritanjali Behera

    2017-12-01

    Full Text Available BACKGROUND Maternal mortality traditionally has been the indicator of maternal health. More recently the review of cases of near miss obstetric event is found to be useful to investigate maternal mortality. Cases of near miss are those, where a woman nearly died but survived a complication that occur during pregnancy or child birth. Aim and Objective 1. To analyse near miss cases and maternal deaths. 2. To determine maternal near miss indicator and to analyse the cause and contributing factors for both of them. MATERIALS AND METHODS This prospective observational study conducted in M.K.C.G. medical college, Berhampur from 1st October 2015 to 30th September 2017. All the cases of maternal deaths and near miss cases defined by WHO criteria are taken. Information regarding demographic profile and reproductive parameters are collected and results are analysed using percentage and proportion. RESULTS Out of 17977 deliveries 201 were near miss cases and 116 were maternal deaths. MMR was 681, near miss incidence 1.18, maternal death to near miss ratio was 1:1.73. Hypertensive disorder of pregnancy (37.4% was the leading cause followed by haemorrhage (17.4%. For near miss cases 101 cases fulfilled clinical criteria, 61 laboratory criteria and 131 cases management based criteria. CONCLUSION Hypertensive disorder of pregnancy and haemorrhage are the leading cause of maternal death and for near miss cases most common organ system involved was cardiovascular system. All the near miss cases should be interpreted as opportunities to improve the health care services.

  19. Handling missing values in the MDS-UPDRS.

    Science.gov (United States)

    Goetz, Christopher G; Luo, Sheng; Wang, Lu; Tilley, Barbara C; LaPelle, Nancy R; Stebbins, Glenn T

    2015-10-01

    This study was undertaken to define the number of missing values permissible to render valid total scores for each Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part. To handle missing values, imputation strategies serve as guidelines to reject an incomplete rating or create a surrogate score. We tested a rigorous, scale-specific, data-based approach to handling missing values for the MDS-UPDRS. From two large MDS-UPDRS datasets, we sequentially deleted item scores, either consistently (same items) or randomly (different items) across all subjects. Lin's Concordance Correlation Coefficient (CCC) compared scores calculated without missing values with prorated scores based on sequentially increasing missing values. The maximal number of missing values retaining a CCC greater than 0.95 determined the threshold for rendering a valid prorated score. A second confirmatory sample was selected from the MDS-UPDRS international translation program. To provide valid part scores applicable across all Hoehn and Yahr (H&Y) stages when the same items are consistently missing, one missing item from Part I, one from Part II, three from Part III, but none from Part IV can be allowed. To provide valid part scores applicable across all H&Y stages when random item entries are missing, one missing item from Part I, two from Part II, seven from Part III, but none from Part IV can be allowed. All cutoff values were confirmed in the validation sample. These analyses are useful for constructing valid surrogate part scores for MDS-UPDRS when missing items fall within the identified threshold and give scientific justification for rejecting partially completed ratings that fall below the threshold. © 2015 International Parkinson and Movement Disorder Society.

  20. An interference account of the missing-VP effect

    Directory of Open Access Journals (Sweden)

    Markus eBader

    2015-06-01

    Full Text Available Sentences with doubly center-embedded relative clauses in which a verb phrase (VP is missing are sometimes perceived as grammatical, thus giving rise to an illusion of grammaticality. In this paper, we provide a new account of why missing-VP sentences, which are both complex and ungrammatical, lead to an illusion of grammaticality, the so-called missing-VP effect. We propose that the missing-VP effect in particular, and processing difficulties with multiply center-embedded clauses more generally, are best understood as resulting from interference during cue-based retrieval. When processing a sentence with double center-embedding, a retrieval error due to interference can cause the verb of an embedded clause to be erroneously attached into a higher clause. This can lead to an illusion of grammaticality in the case of missing-VP sentences and to processing complexity in the case of complete sentences with double center-embedding. Evidence for an interference account of the missing-VP effect comes from experiments that have investigated the missing-VP effect in German using a speeded grammaticality judgments procedure. We review this evidence and then present two new experiments that show that the missing VP effect can be found in German also with less restricting procedures. One experiment was a questionnaire study which required grammaticality judgments from participants but without imposing any time constraints. The second experiment used a self-paced reading procedure and did not require any judgments. Both experiments confirm the prior findings of missing-VP effects in German and also show that the missing-VP effect is subject to a primacy effect as known from the memory literature. Based on this evidence, we argue that an account of missing-VP effects in terms of interference during cue-based retrieval is superior to accounts in terms of limited memory resources or in terms of experience with embedded structures.

  1. EVOLUTION OF THE BINARY FRACTION IN DENSE STELLAR SYSTEMS

    International Nuclear Information System (INIS)

    Fregeau, John M.; Ivanova, Natalia; Rasio, Frederic A.

    2009-01-01

    Using our recently improved Monte Carlo evolution code, we study the evolution of the binary fraction in globular clusters. In agreement with previous N-body simulations, we find generally that the hard binary fraction in the core tends to increase with time over a range of initial cluster central densities for initial binary fractions ∼<90%. The dominant processes driving the evolution of the core binary fraction are mass segregation of binaries into the cluster core and preferential destruction of binaries there. On a global scale, these effects and the preferential tidal stripping of single stars tend to roughly balance, leading to overall cluster binary fractions that are roughly constant with time. Our findings suggest that the current hard binary fraction near the half-mass radius is a good indicator of the hard primordial binary fraction. However, the relationship between the true binary fraction and the fraction of main-sequence stars in binaries (which is typically what observers measure) is nonlinear and rather complicated. We also consider the importance of soft binaries, which not only modify the evolution of the binary fraction, but can also drastically change the evolution of the cluster as a whole. Finally, we briefly describe the recent addition of single and binary stellar evolution to our cluster evolution code.

  2. Cannabis and psychosis: have we found the missing links?

    Science.gov (United States)

    Parakh, Preeti; Basu, Debasish

    2013-08-01

    The association between cannabis and psychosis has long been a matter of debate, with cannabis widely perceived as a harmless recreational drug. Electronic bibliographic databases like PubMed and Google Scholar were searched using the format "(psychosis or schizophrenia or synonyms) and (cannabis or synonyms)". Cross-linked searches were made taking the lead from key articles. Recent articles and those exploring the genetic factors or gene-environment interaction between cannabis use and psychosis were focussed upon. Heavy cannabis use at a n young age, in association with genetic liability to psychosis and exposure to environmental stressors like childhood trauma and urban upbringing increases the risk of psychotic outcome in later life. Cannabis acts as a component cause of psychosis, that is, it increases the risk of psychosis in people with certain genetic or environmental vulnerabilities, though by itself, it is neither a sufficient nor a necessary cause of psychosis. Although significant progress has been made over the last few years, we are yet to find all the missing links. Further work is necessary to identify all the factors that underlie individual vulnerability to cannabis-related psychosis and to elucidate the biological mechanisms underlying this risk. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Hybrid Black-Hole Binary Initial Data

    Science.gov (United States)

    Mundim, Bruno C.; Kelly, Bernard J.; Nakano, Hiroyuki; Zlochower, Yosef; Campanelli, Manuela

    2010-01-01

    "Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class. Quantum Grav. 27:114005 (2010)], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculations was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features."

  4. Optimized reversible binary-coded decimal adders

    DEFF Research Database (Denmark)

    Thomsen, Michael Kirkedal; Glück, Robert

    2008-01-01

    Abstract Babu and Chowdhury [H.M.H. Babu, A.R. Chowdhury, Design of a compact reversible binary coded decimal adder circuit, Journal of Systems Architecture 52 (5) (2006) 272-282] recently proposed, in this journal, a reversible adder for binary-coded decimals. This paper corrects and optimizes...... their design. The optimized 1-decimal BCD full-adder, a 13 × 13 reversible logic circuit, is faster, and has lower circuit cost and less garbage bits. It can be used to build a fast reversible m-decimal BCD full-adder that has a delay of only m + 17 low-power reversible CMOS gates. For a 32-decimal (128-bit....... Keywords: Reversible logic circuit; Full-adder; Half-adder; Parallel adder; Binary-coded decimal; Application of reversible logic synthesis...

  5. A binary mixture operated heat pump

    International Nuclear Information System (INIS)

    Hihara, E.; Saito, T.

    1991-01-01

    This paper evaluates the performance of possible binary mixtures as working fluids in high- temperature heat pump applications. The binary mixtures, which are potential alternatives of fully halogenated hydrocarbons, include HCFC142b/HCFC22, HFC152a/HCFC22, HFC134a/HCFC22. The performance of the mixtures is estimated by a thermodynamic model and a practical model in which the heat transfer is considered in heat exchangers. One of the advantages of binary mixtures is a higher coefficient of performance, which is caused by the small temperature difference between the heat-sink/-source fluid and the refrigerant. The mixture HCFC142b/HCFC22 is promising from the stand point of thermodynamic performance

  6. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    International Nuclear Information System (INIS)

    Fuller, Jim; Lai Dong

    2012-01-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10 5 -10 6 years.

  7. Compact binary hashing for music retrieval

    Science.gov (United States)

    Seo, Jin S.

    2014-03-01

    With the huge volume of music clips available for protection, browsing, and indexing, there is an increased attention to retrieve the information contents of the music archives. Music-similarity computation is an essential building block for browsing, retrieval, and indexing of digital music archives. In practice, as the number of songs available for searching and indexing is increased, so the storage cost in retrieval systems is becoming a serious problem. This paper deals with the storage problem by extending the supervector concept with the binary hashing. We utilize the similarity-preserving binary embedding in generating a hash code from the supervector of each music clip. Especially we compare the performance of the various binary hashing methods for music retrieval tasks on the widely-used genre dataset and the in-house singer dataset. Through the evaluation, we find an effective way of generating hash codes for music similarity estimation which improves the retrieval performance.

  8. Editorial: Let's talk about sex - the gender binary revisited.

    Science.gov (United States)

    Oldehinkel, Albertine J

    2017-08-01

    Sex refers to biological differences and gender to socioculturally delineated masculine and feminine roles. Sex or gender are included as a covariate or effect modifier in the majority of child psychology and psychiatry studies, and differences found between boys and girls have inspired many researchers to postulate underlying mechanisms. Empirical tests of whether including these proposed explanatory variables actually reduces the variance explained by gender are lagging behind somewhat. That is a pity, because a lot can be gained from a greater focus on the active agents of specific gender differences. As opposed to biological sex as such, some of the processes explaining why a specific outcome shows gender differences may be changeable and so possible prevention targets. Moreover, while the sex binary may be reasonable adequate as a classification variable, the gender binary is far from perfect. Gender is a multidimensional, partly context-dependent factor, and the dichotomy generally used in research does not do justice to the diversity existing within boys and girls. © 2017 Association for Child and Adolescent Mental Health.

  9. Perceptions of randomness in binary sequences: Normative, heuristic, or both?

    Science.gov (United States)

    Reimers, Stian; Donkin, Chris; Le Pelley, Mike E

    2018-03-01

    When people consider a series of random binary events, such as tossing an unbiased coin and recording the sequence of heads (H) and tails (T), they tend to erroneously rate sequences with less internal structure or order (such as HTTHT) as more probable than sequences containing more structure or order (such as HHHHH). This is traditionally explained as a local representativeness effect: Participants assume that the properties of long sequences of random outcomes-such as an equal proportion of heads and tails, and little internal structure-should also apply to short sequences. However, recent theoretical work has noted that the probability of a particular sequence of say, heads and tails of length n, occurring within a larger (>n) sequence of coin flips actually differs by sequence, so P(HHHHH) rational norms based on limited experience. We test these accounts. Participants in Experiment 1 rated the likelihood of occurrence for all possible strings of 4, 5, and 6 observations in a sequence of coin flips. Judgments were better explained by representativeness in alternation rate, relative proportion of heads and tails, and sequence complexity, than by objective probabilities. Experiments 2 and 3 gave similar results using incentivized binary choice procedures. Overall the evidence suggests that participants are not sensitive to variation in objective probabilities of a sub-sequence occurring; they appear to use heuristics based on several distinct forms of representativeness. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Critical incidents and near misses during anesthesia: A prospective audit

    Directory of Open Access Journals (Sweden)

    Pamela Onorame Agbamu

    2017-01-01

    Full Text Available Background: A critical incident is any preventable mishap associated with the administration of anesthesia and which leads to or could have led to an undesirable patients' outcome. Patients' safety can be improved by learning from reported critical incidents and near misses. Materials and Methods: All perioperative critical incidents (excluding obstetrics occurring over 5 months were voluntarily documented in a pro forma. Age of patient, urgency of surgery, grade of anesthetist, and patients' outcome was noted. Results: Seventy-three critical incidents were recorded in 42 patients (incidence 6.1% of 1188 procedures with complete recovery in 88.1% (n = 37 and mortality in 11.9% (n = 5. The highest incidents occurred during elective procedures (71.4%, which were all supervised by consultants, and in patients aged 0–10 years (40.1%. Critical incident categories documented were cardiovascular (41.1%, respiratory (23.25%, vascular access (15.1%, airway/intubation (6.85%, equipment errors (6.85%, difficult/failed regional technique (4.11%, and others (2.74%. The monitors available were: pulse oximetry (100%, precordial stethoscope (90.5%, sphygmomanometer (90.5%, capnography (54.8%, electrocardiogram (31%, and temperature (14.3%. The most probable cause of critical incident was patient factor (38.7% followed by human error (22.5%. Equipment error, pharmacological factor, and surgical factor accounted for 12.9%. Conclusion: Critical incidents can occur in the hands of the highly skilled and even in the presence of adequate monitoring. Protocols should be put in place to avoid errors. Critical incident reporting must be encouraged to improve patients' safety and reduce morbidity and mortality.

  11. The Hunt for Missing Dwarf Galaxies

    Science.gov (United States)

    Kohler, Susanna

    2015-11-01

    Theories of galaxy formation and evolution predict that there should be significantly more dwarf galaxies than have been observed. Are our theories wrong? Or are dwarf galaxies just difficult to detect? Recent results from a survey of a galaxy cluster 62 million light-years away suggest there may be lots of undiscovered dwarf galaxies hiding throughout the universe!Hiding in FaintnessThe missing dwarf problem has had hints of a resolution with the recent discovery of Ultra-Diffuse Galaxies (UDGs) in the Coma and Virgo galaxy clusters. UDGs have low masses and large radii, resulting in a very low surface brightness that makes them extremely difficult to detect. If many dwarfs are UDGs, this could well explain why weve been missing them!But the Coma and Virgo galaxy clusters are similar in that theyre both very massive. Are there UDGs in other galaxy clusters as well? To answer this question, an international team of scientists is running the Next Generation Fornax Survey (NGFS), a survey searching for faint dwarf galaxies in the central 30 square degrees of the Fornax galaxy cluster.The NGFS uses near-UV and optical observations from the Dark Energy Camera mounted on the 4m Blanco Telescope in Chile. The survey is still underway, but in a recent publication led by Roberto P. Muoz (Institute of Astrophysics at the Pontifical Catholic University of Chile), the team has released an overview of the first results from only the central 3 square degrees of the NGFS field.Surprising DetectionGalaxy radii vs. their absolute i-band magnitudes, for the dwarfs found in NGFS as well as other stellar systems in the nearby universe. The NGFS dwarfs are similar to the ultra-diffuse dwarfs found in the Virgo and Coma clusters, but are several orders of magnitude fainter. [Muoz et al. 2015]In just this small central field, the team has found an astounding 284 low-surface-brightness dwarf galaxy candidates 158 of them previously undetected. At the bright end of this sample are dwarf

  12. Reconciliation with non-binary species trees.

    Science.gov (United States)

    Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton; Durand, Dannie

    2008-10-01

    Reconciliation extracts information from the topological incongruence between gene and species trees to infer duplications and losses in the history of a gene family. The inferred duplication-loss histories provide valuable information for a broad range of biological applications, including ortholog identification, estimating gene duplication times, and rooting and correcting gene trees. While reconciliation for binary trees is a tractable and well studied problem, there are no algorithms for reconciliation with non-binary species trees. Yet a striking proportion of species trees are non-binary. For example, 64% of branch points in the NCBI taxonomy have three or more children. When applied to non-binary species trees, current algorithms overestimate the number of duplications because they cannot distinguish between duplication and incomplete lineage sorting. We present the first algorithms for reconciling binary gene trees with non-binary species trees under a duplication-loss parsimony model. Our algorithms utilize an efficient mapping from gene to species trees to infer the minimum number of duplications in O(|V(G) | x (k(S) + h(S))) time, where |V(G)| is the number of nodes in the gene tree, h(S) is the height of the species tree and k(S) is the size of its largest polytomy. We present a dynamic programming algorithm which also minimizes the total number of losses. Although this algorithm is exponential in the size of the largest polytomy, it performs well in practice for polytomies with outdegree of 12 or less. We also present a heuristic which estimates the minimal number of losses in polynomial time. In empirical tests, this algorithm finds an optimal loss history 99% of the time. Our algorithms have been implemented in NOTUNG, a robust, production quality, tree-fitting program, which provides a graphical user interface for exploratory analysis and also supports automated, high-throughput analysis of large data sets.

  13. Microlensing Binaries Discovered through High-magnification Channel

    DEFF Research Database (Denmark)

    Shin, I.-G.; Choi, J.-Y.; Park, S.-Y.

    2012-01-01

    Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturba......Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010...

  14. 9 CFR 2.128 - Inspection for missing animals.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Inspection for missing animals. 2.128 Section 2.128 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.128 Inspection for missing animals. Each dealer...

  15. Why Patients Miss Follow-Up Appointments: A Prospective Control ...

    African Journals Online (AJOL)

    Reasons include: transport (19 responses), ill-health (6) and financial constraints (5). State transport was unavailable to almost twothirds of the responders who cited transport as a problem. Conclusions: The 17% missed appointment rate is largely due to transport constraints. The commonest time for patients to miss ...

  16. 577 Missed opportunities for inununisation in Natal health facilities

    African Journals Online (AJOL)

    Wkly Epidemwl Rec 1984; 59: 117-119. 5. Expanded Programme on Immunization. Missed immunizacion opportunities and acceptability of immunization. Wkly Epidemiol Rec. 1989;64: 181-184. . . 6. Loevinsohn BP. Missed opportunities for immunization during visits for curative care: practical reasons for their occurrence.

  17. 40 CFR 75.37 - Missing data procedures for moisture.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Missing data procedures for moisture... data procedures for moisture. (a) The owner or operator of a unit with a continuous moisture monitoring system shall substitute for missing moisture data using the procedures of this section. (b) Where no...

  18. 40 CFR 98.405 - Procedures for estimating missing data.

    Science.gov (United States)

    2010-07-01

    ... meter malfunctions), a substitute data value for the missing quantity measurement must be used in the... period for any reason, the reporter shall use either its delivering pipeline measurements or the default... § 98.405 Procedures for estimating missing data. (a) Whenever a quality-assured value of the quantity...

  19. Incidence and Correlates of Maternal Near Miss in Southeast Iran

    Directory of Open Access Journals (Sweden)

    Tayebeh Naderi

    2015-01-01

    Full Text Available This prospective study aimed to estimate the incidence and associated factors of severe maternal morbidity in southeast Iran. During a 9-month period in 2013, all women referring to eight hospitals for termination of pregnancy as well as women admitted during 42 days after the termination of pregnancy were enrolled into the study. Maternal near miss conditions were defined based on Say et al.’s recommendations. Five hundred and one cases of maternal near miss and 19,908 live births occurred in the study period, yielding a maternal near miss ratio of 25.2 per 1000 live births. This rate was 7.5 and 105 per 1000 in private and tertiary care settings, respectively. The rate of maternal death in near miss cases was 0.40% with a case:fatality ratio of 250 : 1. The most prevalent causes of near miss were severe preeclampsia (27.3%, ectopic pregnancy (18.4%, and abruptio placentae (16.2%. Higher age, higher education, and being primiparous were associated with a higher risk of near miss. Considering the high rate of maternal near miss in referral hospitals, maternal near miss surveillance system should be set up in these hospitals to identify cases of severe maternal morbidity as soon as possible.

  20. 78 FR 37598 - Missing Participants in Individual Account Plans

    Science.gov (United States)

    2013-06-21

    ... information from the public to assist it in making decisions about implementing a new program to deal with... allocated to such participant's account.'' Before making decisions about implementing a missing participants... PENSION BENEFIT GUARANTY CORPORATION Missing Participants in Individual Account Plans AGENCY...

  1. Handling of incidents, near-misses

    International Nuclear Information System (INIS)

    Renborg, Bo; Jonsson, Klas; Broqvist, Kristoffer; Keski-Seppaelae, Sven

    2006-12-01

    This work has primarily been done as a study of available literature about reporting systems. The following items have also been considered: the participants' experience of safety work in general and reporting systems in particular, as well as correspondence with researchers and organisations that have experience from reporting systems in safety-critical applications. A number of definitions of the English term 'near-miss' have been found in the documentation about safety-critical systems. An important conclusion is that creating a precise definition in itself is not critical. The main objective is to persuade the individuals to report perceived risks as well as actual events or conditions. In this report, we have chosen to use the following definition of what should be reported: A condition or an incident with potential for more serious consequences. The reporting systems that have been evaluated have all data in the same system; they do not divide data into separate systems for incidents or 'near-misses'. The term incident in the literature is not used consistently, especially if both Swedish and English texts are considered. In a large portion of the documentation where the reporting system is mentioned, the focus lies more on analysis than on the problem with the willingness to report. Even when the focus is on reporting it is often dealing with the design of the actual report in order to enable the subsequent treatment of data. In some cases this has led to unnecessary complicated report forms. The cornerstone of a high willingness to report is the creation of a 'no-blame' culture. Based on experience it can be concluded that the question whether a report could lead to personal reprisals is crucial. Even a system that explicitly gives the reporter immunity is still brittle. The bare suspicion (that immunity may vanish) in the mind of the one reporting reduces the willingness to report dramatically. Meaning that the purpose of the analysis of reports must be to

  2. Prediction of insemination outcomes in Holstein dairy cattle using alternative machine learning algorithms.

    Science.gov (United States)

    Shahinfar, Saleh; Page, David; Guenther, Jerry; Cabrera, Victor; Fricke, Paul; Weigel, Kent

    2014-02-01

    When making the decision about whether or not to breed a given cow, knowledge about the expected outcome would have an economic impact on profitability of the breeding program and net income of the farm. The outcome of each breeding can be affected by many management and physiological features that vary between farms and interact with each other. Hence, the ability of machine learning algorithms to accommodate complex relationships in the data and missing values for explanatory variables makes these algorithms well suited for investigation of reproduction performance in dairy cattle. The objective of this study was to develop a user-friendly and intuitive on-farm tool to help farmers make reproduction management decisions. Several different machine learning algorithms were applied to predict the insemination outcomes of individual cows based on phenotypic and genotypic data. Data from 26 dairy farms in the Alta Genetics (Watertown, WI) Advantage Progeny Testing Program were used, representing a 10-yr period from 2000 to 2010. Health, reproduction, and production data were extracted from on-farm dairy management software, and estimated breeding values were downloaded from the US Department of Agriculture Agricultural Research Service Animal Improvement Programs Laboratory (Beltsville, MD) database. The edited data set consisted of 129,245 breeding records from primiparous Holstein cows and 195,128 breeding records from multiparous Holstein cows. Each data point in the final data set included 23 and 25 explanatory variables and 1 binary outcome for of 0.756 ± 0.005 and 0.736 ± 0.005 for primiparous and multiparous cows, respectively. The naïve Bayes algorithm, Bayesian network, and decision tree algorithms showed somewhat poorer classification performance. An information-based variable selection procedure identified herd average conception rate, incidence of ketosis, number of previous (failed) inseminations, days in milk at breeding, and mastitis as the most

  3. A simple model for binary star evolution

    International Nuclear Information System (INIS)

    Whyte, C.A.; Eggleton, P.P.

    1985-01-01

    A simple model for calculating the evolution of binary stars is presented. Detailed stellar evolution calculations of stars undergoing mass and energy transfer at various rates are reported and used to identify the dominant physical processes which determine the type of evolution. These detailed calculations are used to calibrate the simple model and a comparison of calculations using the detailed stellar evolution equations and the simple model is made. Results of the evolution of a few binary systems are reported and compared with previously published calculations using normal stellar evolution programs. (author)

  4. Non-binary or genderqueer genders

    OpenAIRE

    Richards, Christina; Bouman, Walter Pierre; Seal, Leighton; Barker, Meg John; Nieder, Timo O; T'Sjoen, Guy

    2016-01-01

    Some people have a gender which is neither male nor female and may identify as both male and female at one time, as different genders at different times, as no gender at all, or dispute the very idea of only two genders. The umbrella terms for such genders are genderqueer' or non-binary' genders. Such gender identities outside of the binary of female and male are increasingly being recognized in legal, medical and psychological systems and diagnostic classifications in line with the emerging ...

  5. Applications Of Binary Image Analysis Techniques

    Science.gov (United States)

    Tropf, H.; Enderle, E.; Kammerer, H. P.

    1983-10-01

    After discussing the conditions where binary image analysis techniques can be used, three new applications of the fast binary image analysis system S.A.M. (Sensorsystem for Automation and Measurement) are reported: (1) The human view direction is measured at TV frame rate while the subject's head is free movable. (2) Industrial parts hanging on a moving conveyor are classified prior to spray painting by robot. (3) In automotive wheel assembly, the eccentricity of the wheel is minimized by turning the tyre relative to the rim in order to balance the eccentricity of the components.

  6. Sputtering yield calculation for binary target

    International Nuclear Information System (INIS)

    Jimenez-Rodriguez, J.J.; Rodriguez-Vidal, M.; Valles-Abarca, J.A.

    1979-01-01

    The generalization for binary targets, of the ideas proposed by Sigmund for monoatomic targets, leads to a set of coupled intergrodifferential equations for the sputtering functions. After moment decomposition, the final formulae are obtained by the standard method based on the Laplace Transform, where the inverse transform is made with the aid of asymptotic expansions in the limit of very high projectile energy as compared to the surface binding energy. The possible loss of stoichiometry for binary targets is analyzed. Comparison of computed values of sputtering yield for normal incidence, with experimental results shows good agreement. (author)

  7. Binary Sparse Phase Retrieval via Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Wei Peng

    2016-01-01

    Full Text Available This paper presents the Simulated Annealing Sparse PhAse Recovery (SASPAR algorithm for reconstructing sparse binary signals from their phaseless magnitudes of the Fourier transform. The greedy strategy version is also proposed for a comparison, which is a parameter-free algorithm. Sufficient numeric simulations indicate that our method is quite effective and suggest the binary model is robust. The SASPAR algorithm seems competitive to the existing methods for its efficiency and high recovery rate even with fewer Fourier measurements.

  8. Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

    Science.gov (United States)

    Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

    2017-09-01

    We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

  9. The fate of close encounters between binary stars and binary supermassive black holes

    Science.gov (United States)

    Wang, Yi-Han; Leigh, Nathan; Yuan, Ye-Fei; Perna, Rosalba

    2018-04-01

    The evolution of main-sequence binaries that reside in the Galactic Centre can be heavily influenced by the central supermassive black hole (SMBH). Due to these perturbative effects, the stellar binaries in dense environments are likely to experience mergers, collisions, or ejections through secular and/or non-secular interactions. More direct interactions with the central SMBH are thought to produce hypervelocity stars (HVSs) and tidal disruption events (TDEs). In this paper, we use N-body simulations to study the dynamics of stellar binaries orbiting a central SMBH primary with an outer SMBH secondary orbiting this inner triple. The effects of the secondary SMBH on the event rates of HVSs, TDEs, and stellar mergers are investigated, as a function of the SMBH-SMBH binary mass ratio. Our numerical experiments reveal that, relative to the isolated SMBH case, the TDE and HVS rates are enhanced for, respectively, the smallest and largest mass ratio SMBH-SMBH binaries. This suggests that the observed event rates of TDEs and HVSs have the potential to serve as a diagnostic of the mass ratio of a central SMBH-SMBH binary. The presence of a secondary SMBH also allows for the creation of hypervelocity binaries. Observations of these systems could thus constrain the presence of a secondary SMBH in the Galactic Centre.

  10. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenegger, Lisa [MPIA, Koenigstuhl 17, D-69117 Heidelberg (Germany); Haghighipour, Nader, E-mail: kaltenegger@mpia.de [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States)

    2013-11-10

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886.

  11. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    International Nuclear Information System (INIS)

    Kaltenegger, Lisa; Haghighipour, Nader

    2013-01-01

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886

  12. Missed opportunities for HPV immunization among young adult women

    Science.gov (United States)

    Oliveira, Carlos R.; Rock, Robert M.; Shapiro, Eugene D.; Xu, Xiao; Lundsberg, Lisbet; Zhang, Liye B.; Gariepy, Aileen; Illuzzi, Jessica L.; Sheth, Sangini S.

    2018-01-01

    BACKGROUND Despite the availability of a safe and efficacious vaccine against human papillomavirus, uptake of the vaccine in the United States is low. Missed clinical opportunities to recommend and to administer human papillomavirus vaccine are considered one of the most important reasons for its low uptake in adolescents; however, little is known about the frequency or characteristics of missed opportunities in the young adult (18–26 years of age) population. OBJECTIVE The objective of the study was to assess both the rates of and the factors associated with missed opportunities for human papillomavirus immunization among young adult women who attended an urban obstetrics and gynecology clinic. STUDY DESIGN In this cross-sectional study, medical records were reviewed for all women 18–26 years of age who were underimmunized (<3 doses) and who sought care from Feb. 1, 2013, to January 31, 2014, at an urban, hospital-based obstetrics and gynecology clinic. A missed opportunity for human papillomavirus immunization was defined as a clinic visit at which the patient was eligible to receive the vaccine and a dose was due but not administered. Multivariable logistic regression was used to test associations between sociodemographic variables and missed opportunities. RESULTS There were 1670 vaccine-eligible visits by 1241 underimmunized women, with a mean of 1.3 missed opportunities/person. During the study period, 833 of the vaccine eligible women (67.1%) had at least 1 missed opportunity. Overall, the most common types of visits during which a missed opportunity occurred were postpartum visits (17%) or visits for either sexually transmitted disease screening (21%) or contraception (33%). Of the patients with a missed opportunity, 26.5% had a visit at which an injectable medication or a different vaccine was administered. Women who identified their race as black had higher adjusted odds of having a missed opportunity compared with white women (adjusted odds ratio, 1

  13. The Performance of a Rapid Diagnostic Test in Detecting Malaria Infection in Pregnant Women and the Impact of Missed Infections

    DEFF Research Database (Denmark)

    Williams, John E; Cairns, Matthew; Njie, Fanta

    2016-01-01

    BACKGROUND: Intermittent screening and treatment in pregnancy (ISTp) is a potential strategy for the control of malaria during pregnancy. However, the frequency and consequences of malaria infections missed by a rapid diagnostic test (RDT) for malaria are a concern.METHODS: Primigravidae and secu......BACKGROUND: Intermittent screening and treatment in pregnancy (ISTp) is a potential strategy for the control of malaria during pregnancy. However, the frequency and consequences of malaria infections missed by a rapid diagnostic test (RDT) for malaria are a concern.METHODS: Primigravidae...... in 540 women; these were not associated with maternal anemia, placental malaria, or low birth weight. CONCLUSIONS: The sensitivity of an RDT to detect malaria in primigravidae and secundigravidae was high at enrollment in 3 of 4 countries and, in Ghana, at subsequent ANC visits. In Ghana, RDT negative...... malaria infections were not associated with adverse birth outcomes but missed infections were uncommon....

  14. Missing transverse momentum in ATLAS: current and future performance

    CERN Document Server

    Schramm, S; The ATLAS collaboration

    2014-01-01

    During the Run-I data taking period, ATLAS has developed and refined several approaches for measuring missing transverse momentum in proton-proton collisions. Standard calorimeter-based $\\mathrm{E}_\\mathrm{T}^\\mathrm{miss}$ reconstruction techniques have been improved to obtain new levels of precision, while new track-based $\\mathrm{p}_\\mathrm{T}^\\mathrm{miss}$ methods provide for a way to have a second independent measurement of the momentum lost due to particles which do not leave tracks in the inner detectors. While both procedures are individually useful, preliminary studies have shown that combining information from both techniques leads to an improved understanding of missing transverse momentum. Data taking conditions during Run-I varied extensively, especially with respect to the amount of pileup activity present in each event, which provides unique challenges to calorimeter-based $\\mathrm{E}_\\mathrm{T}^\\mathrm{miss}$. Multiple solutions have been demonstrated, including methods which exploit both cal...

  15. MISSE in the Materials and Processes Technical Information System (MAPTIS )

    Science.gov (United States)

    Burns, DeWitt; Finckenor, Miria; Henrie, Ben

    2013-01-01

    Materials International Space Station Experiment (MISSE) data is now being collected and distributed through the Materials and Processes Technical Information System (MAPTIS) at Marshall Space Flight Center in Huntsville, Alabama. MISSE data has been instrumental in many programs and continues to be an important source of data for the space community. To facilitate great access to the MISSE data the International Space Station (ISS) program office and MAPTIS are working to gather this data into a central location. The MISSE database contains information about materials, samples, and flights along with pictures, pdfs, excel files, word documents, and other files types. Major capabilities of the system are: access control, browsing, searching, reports, and record comparison. The search capabilities will search within any searchable files so even if the desired meta-data has not been associated data can still be retrieved. Other functionality will continue to be added to the MISSE database as the Athena Platform is expanded

  16. BROWN DWARF BINARIES FROM DISINTEGRATING TRIPLE SYSTEMS

    International Nuclear Information System (INIS)

    Reipurth, Bo; Mikkola, Seppo

    2015-01-01

    Binaries in which both components are brown dwarfs (BDs) are being discovered at an increasing rate, and their properties may hold clues to their origin. We have carried out 200,000 N-body simulations of three identical stellar embryos with masses drawn from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions within the cloud core, while accreting using Bondi–Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. In order to illustrate 200,000 end-states of such dynamical evolution with accretion, we introduce the “triple diagnostic diagram,” which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations, and statistical properties are derived. The separation distribution function is in good correspondence with observations, showing a steep rise at close separations, peaking around 13 AU and declining more gently, reaching zero at separations greater than 200 AU. Unresolved BD triple systems may appear as wider BD binaries. Mass ratios are strongly peaked toward unity, as observed, but this is partially due to the initial assumptions. Eccentricities gradually increase toward higher values, due to the lack of viscous interactions in the simulations, which would both shrink the orbits and decrease their eccentricities. Most newborn triple systems are unstable and while there are 9209 ejected BD binaries at 1 Myr, corresponding to about 4% of the 200,000 simulations, this number has grown to

  17. BROWN DWARF BINARIES FROM DISINTEGRATING TRIPLE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Reipurth, Bo [Institute for Astronomy and NASA Astrobiology Institute University of Hawaii, 640 N. Aohoku Place, Hilo, HI 96720 (United States); Mikkola, Seppo, E-mail: reipurth@ifa.hawaii.edu, E-mail: Seppo.Mikkola@utu.fi [Tuorla Observatory, University of Turku, Väisäläntie 20, Piikkiö (Finland)

    2015-04-15

    Binaries in which both components are brown dwarfs (BDs) are being discovered at an increasing rate, and their properties may hold clues to their origin. We have carried out 200,000 N-body simulations of three identical stellar embryos with masses drawn from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions within the cloud core, while accreting using Bondi–Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. In order to illustrate 200,000 end-states of such dynamical evolution with accretion, we introduce the “triple diagnostic diagram,” which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations, and statistical properties are derived. The separation distribution function is in good correspondence with observations, showing a steep rise at close separations, peaking around 13 AU and declining more gently, reaching zero at separations greater than 200 AU. Unresolved BD triple systems may appear as wider BD binaries. Mass ratios are strongly peaked toward unity, as observed, but this is partially due to the initial assumptions. Eccentricities gradually increase toward higher values, due to the lack of viscous interactions in the simulations, which would both shrink the orbits and decrease their eccentricities. Most newborn triple systems are unstable and while there are 9209 ejected BD binaries at 1 Myr, corresponding to about 4% of the 200,000 simulations, this number has grown to

  18. Maternal Near-Miss: A Multicenter Surveillance in Kathmandu Valley

    Directory of Open Access Journals (Sweden)

    Ashma Rana

    2013-06-01

    Full Text Available Introduction: Multicenter surveillance has been carried out on maternal near-miss in the hospitals with sentinel units. Near-miss is recognized as the predictor of level of care and maternal death. Reducing maternal mortality ratio is one of the challenges to achieve Millennium Development Goal. Objective was to determine the frequency and the nature of near-miss (severe acute maternal morbidity events and analysis of near-miss morbidities among pregnant women. Methods: Prospective surveillance was done for a year in 2012 in nine hospitals in Kathmandu valley. Cases eligible by definition recorded as a census based on WHO near-miss guideline. Similar questionnaire and dummy tables were used to present the result by non-inferential statistics. Results: Out of 157 cases identified with near-miss rate of 3.8, severe complications were PPH (40% and preeclampsia-eclampsia (17%. Blood transfusion (65%, ICU admission (54% and surgery (32% were the common critical intervention. Oxytocin was the main uterotonic used both prophylactically (86% and therapeutically (76%, and 19% arrived health facility after delivery or abortion. MgSO4 was used in all cases of eclampsia. All of the laparotomies were performed within 3 hours of arrival. Near-miss to mortality ratio was 6:1 and MMR 62. Conclusions: Study result yields similar pattern amongst developing countries and same near-miss conditions as the causes of maternal death reported by national statistics. Process indicators qualify the recommended standard of care. The near-miss event can be used as a surrogate marker of maternal death and a window for system level intervention. Keywords: abortion, eclampsia, hemorrhage, near-miss, surveillance

  19. The Mystery of the Missing Antimatter

    CERN Document Server

    Quinn, Helen R

    2008-01-01

    In the first fractions of a second after the Big Bang lingers a question at the heart of our very existence: why does the universe contain matter but almost no antimatter? The laws of physics tell us that equal amounts of matter and antimatter were produced in the early universe--but then, something odd happened. Matter won out over antimatter; had it not, the universe today would be dark and barren. But how and when did this occur? Helen Quinn and Yossi Nir guide readers into the very heart of this mystery--and along the way offer an exhilarating grand tour of cutting-edge physics. They explain both the history of antimatter and recent advances in particle physics and cosmology. And they discuss the enormous, high-precision experiments that particle physicists are undertaking to test the laws of physics at their most fundamental levels--and how their results reveal tantalizing new possibilities for solving this puzzle at the heart of the cosmos. The Mystery of the Missing Antimatter is at once a history of i...

  20. Why is microcalcification missed on mammography?

    International Nuclear Information System (INIS)

    Peters, Gudrun; Jones, Catherine M.; Daniels, Katie

    2013-01-01

    Ductal carcinoma in situ (DCIS) is often only mammographically evident as microcalcification. Although the overall percentage of screening cases with histologically proven DCIS microcalcification is small, the clinical relevance of missing this finding is significant. The current guidelines in Australia for breast screening departments are for double reading of mammograms to reduce both perceptive and interpretative error. This retrospective study identified patients from a state screening program with histologically proven DCIS whose mammograms showed microcalcification. The initial double reader results were documented according to the 5-point grading scale of BreastScreen Tasmania, and discrepancies between readers were noted. Mammographic factors such as breast density, lesion location, morphology, distribution, size and presence on previous imaging were assessed for significant influence on inter-reader discrepancy. Histological evidence of invasion and grade of malignancy were also analysed. Of 65 identified cases, 29 (45%) showed that one of the two readers had not flagged the microcalcification on the report. Analyses revealed no significant difference in reader discrepancy with any of the analysed factors including breast density, size of microcalcification or presence on previous imaging. Twenty-five of 29 (86%) cases of discrepancy were perceptive. Breast screening reading for microcalcification is poorly correlated to mammographic or histological features. The majority of errors were perceptive rather than interpretative. Double reading is advocated as standard practice to reduce perceptive error.

  1. Search for missing baryons through scintillation

    International Nuclear Information System (INIS)

    Habibi, F.

    2011-06-01

    Cool molecular hydrogen H 2 may be the ultimate possible constituent to the Milky-Way missing baryon. We describe a new way to search for such transparent matter in the Galactic disc and halo, through the diffractive and refractive effects on the light of background stars. By simulating the phase delay induced by a turbulent medium, we computed the corresponding illumination pattern on the earth for an extended source and a given passband. We show that in favorable cases, the light of a background star can be subjected to stochastic fluctuations of the order of a few percent at a characteristic time scale of a few minutes. We have searched for scintillation induced by molecular gas in visible dark nebulae as well as by hypothetical halo clumpuscules of cool molecular hydrogen (H 2 -He) during two nights, using the NTT telescope and the IR SOFI detector. Amongst a few thousands of monitored stars, we found one light-curve that is compatible with a strong scintillation effect through a turbulent structure in the B68 nebula. Because no candidate were found toward the SMC (Small Magellan Cloud), we are able to establish upper limits on the contribution of gas clumpuscules to the Galactic halo mass. We show that the short time-scale monitoring of a few 10 6 star*hour in the visible band with a >4 m telescope and a fast readout camera should allow one to interestingly quantify or constrain the contribution of turbulent molecular gas to the Galactic halo. (author)

  2. Paediatrics and psychoanalysis--Miss Anna Freud.

    Science.gov (United States)

    1983-01-01

    Miss Anna Freud died during the winter at the age of 86. She had been a pioneer in the understanding of children through psychoanalysis and a great champion of the rights of children. Her life began in Vienna as the youngest child of Sigmund Freud, and her early work with children was in Austria. In 1938, because of the Nazi régime and even though she was nursing her father during his terminal illness, she had to escape with him to London. Her work with homeless children and with those in residential nurseries in London during the second world war is well known, as is her work on child development and psychopathology in the postwar years. But one less well known aspect of her life that was of immense importance to a few fortunate British paediatricians was the 'paediatric group' that she ran for over a quarter of a century and which Dr Christine Cooper recalled at the memorial meeting in London earlier this year. PMID:6344806

  3. Using the missed opportunity tool as an application of the Lives Saved Tool (LiST) for intervention prioritization.

    Science.gov (United States)

    Tam, Yvonne; Pearson, Luwei

    2017-11-07

    The Missed Opportunity tool was developed as an application in the Lives Saved Tool (LiST) to allow users to quickly compare the relative impact of interventions. Global Financing Facility (GFF) investment cases have been identified as a potential application of the Missed Opportunity analyses in Democratic Republic of the Congo (DRC), Ethiopia, Kenya, and Tanzania, to use 'lives saved' as a normative factor to set priorities. The Missed Opportunity analysis draws on data and methods in LiST to project maternal, stillbirth, and child deaths averted based on changes in interventions' coverage. Coverage of each individual intervention in LiST was automated to be scaled up from current coverage to 90% in the next year, to simulate a scenario where almost every mother and child receive proven interventions that they need. The main outcome of the Missed Opportunity analysis is deaths averted due to each intervention. When reducing unmet need for contraception is included in the analysis, it ranks as the top missed opportunity across the four countries. When it is not included in the analysis, top interventions with the most total deaths averted are hospital-based interventions such as labor and delivery management in the CEmOC and BEmOC level, and full treatment and supportive care for premature babies, and for sepsis/pneumonia. The Missed Opportunity tool can be used to provide a quick, first look at missed opportunities in a country or geographic region, and help identify interventions for prioritization. While it is a useful advocate for evidence-based priority setting, decision makers need to consider other factors that influence decision making, and also discuss how to implement, deliver, and sustain programs to achieve high coverage.

  4. Missing link or not, mobilise against delirium.

    Science.gov (United States)

    Page, Valerie J; Casarin, Annalisa

    2014-01-31

    Delirium is known to be a predictor of adverse outcomes. In a prospective study Abelha and colleagues showed that postoperative delirium was an independent risk factor for deterioration in functional capacity following discharge. While evidence for causality remains elusive, there is no doubt that patients who develop delirium are left with new functional and cognitive impairment. Finding a pharmacological treatment for the prevention and treatment of delirium is a priority in delirium research and the results of ongoing trials are awaited. Early mobilisation of ICU patients has been demonstrated to decrease delirium and improve functional outcomes. Resources should be directed to appropriate, progressive mobilisation of all critically ill patients as a priority.

  5. Ultracompact X-ray binary stars

    NARCIS (Netherlands)

    Haaften, L.M. van

    2013-01-01

    Ultracompact X-ray binary stars usually consist of a neutron star and a white dwarf, two stars bound together by their strong gravity and orbiting each other very rapidly, completing one orbit in less than one hour. Neutron stars are extremely compact remnants of the collapsed cores of massive stars

  6. Jet precession in binary black holes

    Science.gov (United States)

    Abraham, Zulema

    2018-06-01

    Supermassive binary black holes are thought to lie at the centres of merging galaxies. The blazar OJ 287 is the poster child of such systems, showing strong and periodic variability across the electromagnetic spectrum. A new study questions the physical origin of this variability.

  7. Mesoscopic electrohydrodynamic simulations of binary colloidal suspensions

    NARCIS (Netherlands)

    Rivas, Nicolas; Frijters, Stefan; Pagonabarraga, Ignacio; Harting, Jens

    2018-01-01

    A model is presented for the solution of electrokinetic phenomena of colloidal suspensions in fluid mixtures. We solve the discrete Boltzmann equation with a Bhatnagar-Gross-Krook collision operator using the lattice Boltzmann method to simulate binary fluid flows. Solvent-solvent and solvent-solute

  8. Smoothed analysis of binary search trees

    NARCIS (Netherlands)

    Manthey, Bodo; Reischuk, Rüdiger

    2007-01-01

    Binary search trees are one of the most fundamental data structures. While the height of such a tree may be linear in the worst case, the average height with respect to the uniform distribution is only logarithmic. The exact value is one of the best studied problems in average-case complexity. We

  9. A coinductive calculus of binary trees

    NARCIS (Netherlands)

    A.M. Silva (Alexandra); J.J.M.M. Rutten (Jan)

    2007-01-01

    htmlabstractWe study the set T_A of infinite binary trees with nodes labelled in a semiring A from a coalgebraic perspective. We present coinductive definition and proof principles based on the fact that T_A carries a final coalgebra structure. By viewing trees as formal power series, we develop a

  10. Binary palmprint representation for feature template protection

    NARCIS (Netherlands)

    Mu, Meiru; Ruan, Qiuqi; Shao, X.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.

    2012-01-01

    The major challenge of biometric template protection comes from the intraclass variations of biometric data. The helper data scheme aims to solve this problem by employing the Error Correction Codes (ECC). However, many reported biometric binary features from the same user reach bit error rate (BER)

  11. The average size of ordered binary subgraphs

    NARCIS (Netherlands)

    van Leeuwen, J.; Hartel, Pieter H.

    To analyse the demands made on the garbage collector in a graph reduction system, the change in size of an average graph is studied when an arbitrary edge is removed. In ordered binary trees the average number of deleted nodes as a result of cutting a single edge is equal to the average size of a

  12. Short-timescale variability in cataclysmic binaries

    International Nuclear Information System (INIS)

    Cordova, F.A.; Mason, K.O.

    1982-01-01

    Rapid variability, including flickering and pulsations, has been detected in cataclysmic binaries at optical and x-ray frequencies. In the case of the novalike variable TT Arietis, simultaneous observations reveal that the x-ray and optical flickering activity is strongly correlated, while short period pulsations are observed that occur at the same frequencies in both wavelength bands

  13. Non-binary or genderqueer genders.

    Science.gov (United States)

    Richards, Christina; Bouman, Walter Pierre; Seal, Leighton; Barker, Meg John; Nieder, Timo O; T'Sjoen, Guy

    2016-01-01

    Some people have a gender which is neither male nor female and may identify as both male and female at one time, as different genders at different times, as no gender at all, or dispute the very idea of only two genders. The umbrella terms for such genders are 'genderqueer' or 'non-binary' genders. Such gender identities outside of the binary of female and male are increasingly being recognized in legal, medical and psychological systems and diagnostic classifications in line with the emerging presence and advocacy of these groups of people. Population-based studies show a small percentage--but a sizable proportion in terms of raw numbers--of people who identify as non-binary. While such genders have been extant historically and globally, they remain marginalized, and as such--while not being disorders or pathological in themselves--people with such genders remain at risk of victimization and of minority or marginalization stress as a result of discrimination. This paper therefore reviews the limited literature on this field and considers ways in which (mental) health professionals may assist the people with genderqueer and non-binary gender identities and/or expressions they may see in their practice. Treatment options and associated risks are discussed.

  14. Some thoughts on interacting binary systems

    International Nuclear Information System (INIS)

    Ulrich, R.K.

    1980-01-01

    The author presents some thoughts on the theory and observation of interacting binary systems. The complex physical processes possible in these systems make our present understanding inconclusive. New types of observation (X-ray, EUV, radio) present new challenges to the theoretician. The author discusses those problems which seem to hold the most promise for future progress. (Auth.)

  15. Mass loss from interacting close binary systems

    Science.gov (United States)

    Plavec, M. J.

    1981-01-01

    The three well-defined classes of evolved binary systems that show evidence of present and/or past mass loss are the cataclysmic variables, the Algols, and Wolf-Rayet stars. It is thought that the transformation of supergiant binary systems into the very short-period cataclysmic variables must have been a complex process. The new evidence that has recently been obtained from the far ultraviolet spectra that a certain subclass of the Algols (the Serpentids) are undergoing fairly rapid evolution is discussed. It is thought probable that the remarkable mass outflow observed in them is connected with a strong wind powered by accretion. The origin of the circumbinary clouds or flat disks that probably surround many strongly interacting binaries is not clear. Attention is also given to binary systems with hot white dwarf or subdwarf components, such as the symbiotic objects and the BQ stars; it is noted that in them both components may be prone to an enhanced stellar wind.

  16. Stretchable Binary Fresnel Lens for Focus Tuning

    NARCIS (Netherlands)

    Li, X.; Wei, L.; Poelma, R.H.; Vollebregt, S.; Wei, J.; Urbach, Paul; Sarro, P.M.; Zhang, G.Q.

    2016-01-01

    This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material

  17. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  18. Compiler-Agnostic Function Detection in Binaries

    NARCIS (Netherlands)

    Andriesse, D.A.; Slowinska, J.M.; Bos, H.J.

    2017-01-01

    We propose Nucleus, a novel function detection algorithm for binaries. In contrast to prior work, Nucleus is compiler-agnostic, and does not require any learning phase or signature information. Instead of scanning for signatures, Nucleus detects functions at the Control Flow Graph-level, making it

  19. Photometric survey of asynchronous binary asteroids

    Czech Academy of Sciences Publication Activity Database

    Pravec, Petr; Scheirich, Peter; Kušnirák, Peter; Kotková, Lenka; Mottola, S.; Hahn, G.; Brown, P.; Esquerdo, G.; Kaiser, K.; Krzeminski, Z.; Pray, D. P.; Warner, B. D.; Harris, A. W.; Nolan, M. C.; Howell, E. S.; Benner, L. A. M.; Margot, J. L.; Galád, Adrián; Holliday, W.; Hicks, M. D.; Krugly, Yu. N.; Tholen, D.; Whiteley, R.; Marchis, F.; DeGraff, D. R.; Grauer, A.; Larson, S. M.; Velichko, F. P.; Cooney, W.R.; Stephens, R.; Zhu, J.; Kirsch, K.; Dyvig, R.; Snyder, L.; Reddy, V.; Moore, S.; Gajdoš, Š.; Világi, J.; Masi, G.; Higgins, D.; Funkhouser, G. M.; Knight, B.; Slivan, S. M.; Behrend, R.; Grenon, M.; Burki, G.; Roy, R.; Demeautis, C.; Matter, D.; Waelchli, N.; Revaz, Y.; Klotz, A.; Rieugné, M.; Thieri, P.; Cotrez, V.; Brunetto, L.; Kober, G.

    2006-01-01

    Roč. 181, č. 1 (2006), s. 63-93 ISSN 0019-1035 R&D Projects: GA ČR GA205/05/0604; GA AV ČR IAA3003204 Institutional research plan: CEZ:AV0Z10030501 Keywords : asteroids * binary * photometry Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.151, year: 2006

  20. Planar quark diagrams and binary spin processes

    International Nuclear Information System (INIS)

    Grigoryan, A.A.; Ivanov, N.Ya.

    1986-01-01

    Contributions of planar diagrams to the binary scattering processes are analyzed. The analysis is based on the predictions of quark-gluon picture of strong interactions for the coupling of reggeons with quarks as well as on the SU(6)-classification of hadrons. The dependence of contributions of nonplanar corrections on spins and quark composition of interacting particles is discussed

  1. Binary translation using peephole translation rules

    Science.gov (United States)

    Bansal, Sorav; Aiken, Alex

    2010-05-04

    An efficient binary translator uses peephole translation rules to directly translate executable code from one instruction set to another. In a preferred embodiment, the translation rules are generated using superoptimization techniques that enable the translator to automatically learn translation rules for translating code from the source to target instruction set architecture.

  2. Predicting Social Trust with Binary Logistic Regression

    Science.gov (United States)

    Adwere-Boamah, Joseph; Hufstedler, Shirley

    2015-01-01

    This study used binary logistic regression to predict social trust with five demographic variables from a national sample of adult individuals who participated in The General Social Survey (GSS) in 2012. The five predictor variables were respondents' highest degree earned, race, sex, general happiness and the importance of personally assisting…

  3. Face Alignment via Regressing Local Binary Features.

    Science.gov (United States)

    Ren, Shaoqing; Cao, Xudong; Wei, Yichen; Sun, Jian

    2016-03-01

    This paper presents a highly efficient and accurate regression approach for face alignment. Our approach has two novel components: 1) a set of local binary features and 2) a locality principle for learning those features. The locality principle guides us to learn a set of highly discriminative local binary features for each facial landmark independently. The obtained local binary features are used to jointly learn a linear regression for the final output. This approach achieves the state-of-the-art results when tested on the most challenging benchmarks to date. Furthermore, because extracting and regressing local binary features are computationally very cheap, our system is much faster than previous methods. It achieves over 3000 frames per second (FPS) on a desktop or 300 FPS on a mobile phone for locating a few dozens of landmarks. We also study a key issue that is important but has received little attention in the previous research, which is the face detector used to initialize alignment. We investigate several face detectors and perform quantitative evaluation on how they affect alignment accuracy. We find that an alignment friendly detector can further greatly boost the accuracy of our alignment method, reducing the error up to 16% relatively. To facilitate practical usage of face detection/alignment methods, we also propose a convenient metric to measure how good a detector is for alignment initialization.

  4. Structure Map for Embedded Binary Alloy Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, C.W.; Shin, S.J.; Liao, C.Y.; Guzman, J.; Stone, P.R.; Watanabe, M.; Ager III, J.W.; Haller, E.E.; Chrzan, D.C.

    2008-09-20

    The equilibrium structure of embedded nanocrystals formed from strongly segregating binary-alloys is considered within a simple thermodynamic model. The model identifies two dimensionlessinterface energies that dictate the structure, and allows prediction of the stable structure for anychoice of these parameters. The resulting structure map includes three distinct nanocrystal mor-phologies: core/shell, lobe/lobe, and completely separated spheres.

  5. ANGULAR-MOMENTUM IN BINARY SPIRAL GALAXIES

    NARCIS (Netherlands)

    OOSTERLOO, T

    In order to investigate the relative orientations of spiral galaxies in pairs, the distribution of the angle between the spin-vectors for a new sample of 40 binary spiral galaxies is determined. From this distribution it is found, contrary to an earlier result obtained by Helou (1984), that there is

  6. Gravitational waves from binary black holes

    Indian Academy of Sciences (India)

    Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore ... In the 1916 paper exploring the physical implications of GR, Einstein .... Thus, for a neutron star binary in the Virgo cluster (D = 18 Mpc; 5.6×1020 km) the strain.

  7. The Binary Pulsar: Gravity Waves Exist.

    Science.gov (United States)

    Will, Clifford

    1987-01-01

    Reviews the history of pulsars generally and the 1974 discovery of the binary pulsar by Joe Taylor and Russell Hulse specifically. Details the data collection and analysis used by Taylor and Hulse. Uses this discussion as support for Albert Einstein's theory of gravitational waves. (CW)

  8. Receptive fields selection for binary feature description.

    Science.gov (United States)

    Fan, Bin; Kong, Qingqun; Trzcinski, Tomasz; Wang, Zhiheng; Pan, Chunhong; Fua, Pascal

    2014-06-01

    Feature description for local image patch is widely used in computer vision. While the conventional way to design local descriptor is based on expert experience and knowledge, learning-based methods for designing local descriptor become more and more popular because of their good performance and data-driven property. This paper proposes a novel data-driven method for designing binary feature descriptor, which we call receptive fields descriptor (RFD). Technically, RFD is constructed by thresholding responses of a set of receptive fields, which are selected from a large number of candidates according to their distinctiveness and correlations in a greedy way. Using two different kinds of receptive fields (namely rectangular pooling area and Gaussian pooling area) for selection, we obtain two binary descriptors RFDR and RFDG .accordingly. Image matching experiments on the well-known patch data set and Oxford data set demonstrate that RFD significantly outperforms the state-of-the-art binary descriptors, and is comparable with the best float-valued descriptors at a fraction of processing time. Finally, experiments on object recognition tasks confirm that both RFDR and RFDG successfully bridge the performance gap between binary descriptors and their floating-point competitors.

  9. Binary nucleation of water and sodium chloride

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František; Palmer, A.

    2006-01-01

    Roč. 124, č. 4 (2006), 0445091-0445096 ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA101/05/2536 Institutional research plan: CEZ:AV0Z20760514 Keywords : binary nucleation * sodium chloride * water Subject RIV: BJ - Thermodynamics Impact factor: 3.166, year: 2006

  10. The Benchmark Eclipsing Binary V530 Ori

    DEFF Research Database (Denmark)

    Torres, Guillermo; Lacy, Claud H. Sandberg; Pavlovski, Kresimir

    2015-01-01

    We report accurate measurements of the physical properties (mass, radius, temperature) of components of the G+M eclipsing binary V530 On. The M-type secondary shows a larger radius and a cooler temperature than predicted by standard stellar evolution models, as has been found for many other low...

  11. Void formation in irradiated binary nickel alloys

    International Nuclear Information System (INIS)

    Shaikh, M.A.; Ahmed, M.; Akhter, J.I.

    1994-01-01

    In this work a computer program has been used to compute void radius, void density and swelling parameter for nickel and binary nickel-carbon alloys irradiated with nickel ions of 100 keV. The aim is to compare the computed results with experimental results already reported

  12. Evolution of binaries with compact objects in globular clusters

    OpenAIRE

    Ivanova, Natalia

    2017-01-01

    Dynamical interactions that take place between objects in dense stellar systems lead to frequent formation of exotic stellar objects, unusual binaries, and systems of higher multiplicity. They are most important for the formation of binaries with neutron stars and black holes, which are usually observationally revealed in mass-transferring binaries. Here we review the current understanding of compact object's retention, of the metallicity dependence on the formation of low-mass X-ray binaries...

  13. Influence of non-binary effects on intranuclear cascade method

    International Nuclear Information System (INIS)

    Gomes, E.H.C.

    1985-01-01

    The importance of non binary process effects in the intranuclear cascade method is analysed. It is shown that, in the higher density steps, the non binary collisions lead to baryon density distribution and rapidity differents from the one obtained using the usual intranuclear cascade method (limited to purely binary collisions). The validity of the applications of binary intranuclear cascade method to the simulation of the thermal equilibrium, nuclear transparency and particle production, is discussed. (M.C.K.) [pt

  14. Gravitational waves from spinning eccentric binaries

    Science.gov (United States)

    Csizmadia, Péter; Debreczeni, Gergely; Rácz, István; Vasúth, Mátyás

    2012-12-01

    This paper is to introduce a new software called CBwaves which provides a fast and accurate computational tool to determine the gravitational waveforms yielded by generic spinning binaries of neutron stars and/or black holes on eccentric orbits. This is done within the post-Newtonian (PN) framework by integrating the equations of motion and the spin precession equations, while the radiation field is determined by a simultaneous evaluation of the analytic waveforms. In applying CBwaves various physically interesting scenarios have been investigated. In particular, we have studied the appropriateness of the adiabatic approximation, and justified that the energy balance relation is indeed insensitive to the specific form of the applied radiation reaction term. By studying eccentric binary systems, it is demonstrated that circular template banks are very ineffective in identifying binaries even if they possess tiny residual orbital eccentricity, thus confirming a similar result obtained by Brown and Zimmerman (2010 Phys. Rev. D 81 024007). In addition, by investigating the validity of the energy balance relation we show that, contrary to the general expectations, the PN approximation should not be applied once the PN parameter gets beyond the critical value ˜0.08 - 0.1. Finally, by studying the early phase of the gravitational waves emitted by strongly eccentric binary systems—which could be formed e.g. in various many-body interactions in the galactic halo—we have found that they possess very specific characteristics which may be used to identify these type of binary systems. This paper is dedicated to the memory of our colleague and friend Péter Csizmadia a young physicist, computer expert and one of the best Hungarian mountaineers who disappeared in China’s Sichuan near the Ren Zhong Feng peak of the Himalayas on 23 Oct. 2009. We started to develop CBwaves jointly with Péter a couple of months before he left for China.

  15. Probabilistic seismic history matching using binary images

    Science.gov (United States)

    Davolio, Alessandra; Schiozer, Denis Jose

    2018-02-01

    Currently, the goal of history-matching procedures is not only to provide a model matching any observed data but also to generate multiple matched models to properly handle uncertainties. One such approach is a probabilistic history-matching methodology based on the discrete Latin Hypercube sampling algorithm, proposed in previous works, which was particularly efficient for matching well data (production rates and pressure). 4D seismic (4DS) data have been increasingly included into history-matching procedures. A key issue in seismic history matching (SHM) is to transfer data into a common domain: impedance, amplitude or pressure, and saturation. In any case, seismic inversions and/or modeling are required, which can be time consuming. An alternative to avoid these procedures is using binary images in SHM as they allow the shape, rather than the physical values, of observed anomalies to be matched. This work presents the incorporation of binary images in SHM within the aforementioned probabilistic history matching. The application was performed with real data from a segment of the Norne benchmark case that presents strong 4D anomalies, including softening signals due to pressure build up. The binary images are used to match the pressurized zones observed in time-lapse data. Three history matchings were conducted using: only well data, well and 4DS data, and only 4DS. The methodology is very flexible and successfully utilized the addition of binary images for seismic objective functions. Results proved the good convergence of the method in few iterations for all three cases. The matched models of the first two cases provided the best results, with similar well matching quality. The second case provided models presenting pore pressure changes according to the expected dynamic behavior (pressurized zones) observed on 4DS data. The use of binary images in SHM is relatively new with few examples in the literature. This work enriches this discussion by presenting a new

  16. Reduction of artefacts due to missing projections using OSEM

    International Nuclear Information System (INIS)

    Hutton, B.F.; Kyme, A.; Choong, K.

    2002-01-01

    Full text: It is well recognised that missing or corrupted projections can result in artefacts. This occasionally occurs due to errors in data transfer from acquisition memory to disk. A possible approach for reducing these artefacts was investigated, Using ordered subsets expectation maximization (OSEM) the iterative reconstruction proceeds by progressively including additional projections until a single iteration is complete. Clinically useful results can be obtained using a small subset size in a single iteration. Stopping prior to the complete iteration so as to avoid inclusion of missing or corrupted data should provide a 'partial' reconstruction with minimal artefacts. To test this hypothesis projections were selectively removed from a complete data set (2, 4, 8, 12 adjacent projections) and reconstructions were performed using both filtered back projection (FBP) and OSEM. To maintain a constant number of sub-iterations in OSEM an equal number of duplicate projections were substituted for the missing projections. Both 180 and 360 degrees reconstructions with missing data were compared with reconstruction for the complete data using sum of absolute differences. Results indicate that missing data causes artefacts for both FBP and OSEM however the severity of artefacts is significantly reduced using OSEM. The effect of missing data is generally greater for 180 degrees acquisition. OSEM is recommended for minimising reconstruction artefacts due to missing projections. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  17. Recurrent Neural Networks for Multivariate Time Series with Missing Values.

    Science.gov (United States)

    Che, Zhengping; Purushotham, Sanjay; Cho, Kyunghyun; Sontag, David; Liu, Yan

    2018-04-17

    Multivariate time series data in practical applications, such as health care, geoscience, and biology, are characterized by a variety of missing values. In time series prediction and other related tasks, it has been noted that missing values and their missing patterns are often correlated with the target labels, a.k.a., informative missingness. There is very limited work on exploiting the missing patterns for effective imputation and improving prediction performance. In this paper, we develop novel deep learning models, namely GRU-D, as one of the early attempts. GRU-D is based on Gated Recurrent Unit (GRU), a state-of-the-art recurrent neural network. It takes two representations of missing patterns, i.e., masking and time interval, and effectively incorporates them into a deep model architecture so that it not only captures the long-term temporal dependencies in time series, but also utilizes the missing patterns to achieve better prediction results. Experiments of time series classification tasks on real-world clinical datasets (MIMIC-III, PhysioNet) and synthetic datasets demonstrate that our models achieve state-of-the-art performance and provide useful insights for better understanding and utilization of missing values in time series analysis.

  18. Geochemical modelling: what phenomena are missing

    International Nuclear Information System (INIS)

    Jacquier, P.

    1989-12-01

    In the framework of safety assessment of radioactive waste disposal, retention phenomena are usually taken into account by the Kd concept. It is well recognized that this concept is not enough for safety assessment models, because of the several and strong assumptions which are involved in this kind of representation. One way to have a better representation of the retention phenomena, is to substitute for this Kd concept an explicit description of geochemical phenomena and then couple transport codes with geochemical codes in a fully or a two-step procedure. We use currently such codes, but the scope of this paper is to display the limits today of the geochemical modelling in connection with sites analysis for deep disposal. In this paper, we intend to give an overview of phenomena which are missing in the geochemical models, or which are not completely introduced in the models. We can distinguish, on one hand phenomena for which modelling concepts exist such as adsorption/desorption and, on the other hand, phenomena for which modelling concepts do not exist for the moment such as colloids, and complexation by polyelectrolyte solutions (organics). Moreover we have to take care of very low concentrations of radionuclides, which can be expected from the leaching processes in the repository. Under those conditions, some reactions may not occur. After a critical review of the involved phenomena, we intend to stress the main directions of the wishful evolution of the geochemical modelling. This evolution should improve substantially the quality of the above-mentioned site assessments

  19. China's "missing girls": prospects and policy.

    Science.gov (United States)

    Riley, N E

    1996-02-01

    Women's conditions in China are viewed as deteriorating. The reduction in government control over urban factories and other places of employment has resulted in fewer women being hired. This leaves women in positions with low wages, poor working conditions, and discrimination based on sex, age, and marital status. The shift from rural state-controlled agricultural collectives to patriarchal family controls resulted in land distribution that gave men preference. The rapid growth in the economy and higher standards of living placed women at risk. Although the pressures to kill girl babies have relaxed, there is growing interest in making money from abducting and selling women for prostitution, marriage, and slavery. Women gained in recent decades greater participation in the labor force and higher educational levels. Women's access to health care is better. Female life expectancy is 72 years compared to 69 years for men. Maternal mortality is 95 deaths per 100,000 live births. Yet women hold subordinate positions to men in their jobs, and women are segregated in the textile and service industries. Women in rural areas have primarily access to agricultural jobs, which can be combined with child care. Women are less likely to be promoted and are retired 5 years earlier than men. Women carry a double burden of domestic labor and paid or unpaid labor. Women still have higher illiteracy rates than men, and the gender gap in higher education has remained stable since the 1970s. The imbalanced sex ratio is increasing. In some provinces it is 114 males for every 100 females, when the normal ratio is 105-106 males per 100 females. An estimated 12% of females are unaccounted for each year. The reasons for the missing children are identified as sex-selective abortion, infanticide, or underreporting. The next five-year plan holds the hope for improvement in women's status and an end to abuses against women and children.

  20. The Mysterious Case of the Missing Filaments

    Science.gov (United States)

    Alden, C. R.

    2016-12-01

    Coronal Mass Ejections, or CMEs, are large solar eruptions that can have major debilitating impacts on society. Typically, these eruptions have the three following key structures: the leading edge, the empty chamber known as the cavity, and the filament which often is the brightest part of the CME. When we can see all three structures clearly with a coronagraph, it is called a classic three-part CME, also referred to as a 'lightbulb' CME. According to current knowledge, when a CME erupts, a filament should also erupt or lift off the Sun in order to have the bright center within the CME. However, we do not always see a filament erupt at the surface, and yet we still get a 'filament' within the coronagraph CME. To better understand what might be occurring with these missing filaments, we looked at three-part CMEs using the SOHO LASCO CME Catalog and filaments from the SDO AIA Filament Catalog in order to create a list of 50 CMEs without a listed filament erupting at the surface. For those CMEs without filaments in the list we closely inspected the AIA images for evidence of filament eruption. To ensure that there were no filaments past the limb of the Sun, we used data from the STEREO-A and STEREO-B spacecraft's to look at the Sun from other angles. We have found numerous events where no filament erupts from the surface, but we still see the classic three-part CME. We believe this may be due to an optical illusion occurring from the twisting of the flux rope.

  1. Full Ionisation In Binary-Binary Encounters With Small Positive Energies

    Science.gov (United States)

    Sweatman, W. L.

    2006-08-01

    Interactions between binary stars and single stars and binary stars and other binary stars play a key role in the dynamics of a dense stellar system. Energy can be transferred between the internal dynamics of a binary and the larger scale dynamics of the interacting objects. Binaries can be destroyed and created by the interaction. In a binary-binary encounter, full ionisation occurs when both of the binary stars are destroyed in the interaction to create four single stars. This is only possible when the total energy of the system is positive. For very small energies the probability of this occurring is very low and it tends towards zero as the total energy tends towards zero. Here the case is considered for which all the stars have equal masses. An asymptotic power law is predicted relating the probability of full ionisation with the total energy when this latter quantity is small. The exponent, which is approximately 2.31, is compared with the results from numerical scattering experiments. The theoretical approach taken is similar to one used previously in the three-body problem. It makes use of the fact that the most dramatic changes in scale and energies of a few-body system occur when its components pass near to a central configuration. The position, and number, of these configurations is not known for the general four-body problem, however, with equal masses there are known to be exactly five different cases. Separate consideration and comparison of the properties of orbits close to each of these five central configurations enables the prediction of the form of the cross-section for full ionisation for the case of small positive total energy. This is the relation between total energy and the probability of total ionisation described above.

  2. Maternal near-miss: a multicenter surveillance in Kathmandu Valley.

    Science.gov (United States)

    Rana, Ashma; Baral, Gehanath; Dangal, Ganesh

    2013-01-01

    Multicenter surveillance has been carried out on maternal near-miss in the hospitals with sentinel units. Near-miss is recognized as the predictor of level of care and maternal death. Reducing Maternal Mortality Ratio is one of the challenges to achieve Millennium Development Goal. The objective was to determine the frequency and the nature of near-miss events and to analyze the near-miss morbidities among pregnant women. A prospective surveillance was done for a year in 2012 at nine hospitals in Kathmandu valley. Cases eligible by definition were recorded as a census based on WHO near-miss guideline. Similar questionnaires and dummy tables were used to present the results by non-inferential statistics. Out of 157 cases identified with near-miss rate of 3.8 per 1000 live births, severe complications were postpartum hemorrhage 62 (40%) and preeclampsia-eclampsia 25 (17%). Blood transfusion 102 (65%), ICU admission 85 (54%) and surgery 53 (32%) were common critical interventions. Oxytocin was main uterotonic used both prophylactically and therapeutically at health facilities. Total of 30 (19%) cases arrived at health facility after delivery or abortion. MgSO4 was used in all cases of eclampsia. All laparotomies were performed within three hours of arrival. Near-miss to maternal death ratio was 6:1 and MMR was 62. Study result yielded similar pattern amongst developing countries and same near-miss conditions as the causes of maternal death reported by national statistics. Process indicators qualified the recommended standard of care. The near-miss event could be used as a surrogate marker of maternal death and a window for system level intervention.

  3. Compact stars and the evolution of binary systems

    NARCIS (Netherlands)

    van den Heuvel, E.P.J.

    2011-01-01

    The Chandrasekhar limit is of key importance for the evolution of white dwarfs in binary systems and for the formation of neutron stars and black holes in binaries. Mass transfer can drive a white dwarf in a binary over the Chandrasekhar limit, which may lead to a Type Ia supernova (in case of a CO

  4. Missing and Spurious Level Corrections for Nuclear Resonances

    International Nuclear Information System (INIS)

    Mitchell, G E; Agvaanluvsan, U; Pato, M P; Shriner, J F

    2005-01-01

    Neutron and proton resonances provide detailed level density information. However, due to experimental limitations, some levels are missed and some are assigned incorrect quantum numbers. The standard method to correct for missing levels uses the experimental widths and the Porter-Thomas distribution. Analysis of the spacing distribution provides an independent determination of the fraction of missing levels. We have derived a general expression for such an imperfect spacing distribution using the maximum entropy principle and applied it to a variety of nuclear resonance data. The problem of spurious levels has not been extensively addressed

  5. Topology-Based Estimation of Missing Smart Meter Readings

    Directory of Open Access Journals (Sweden)

    Daisuke Kodaira

    2018-01-01

    Full Text Available Smart meters often fail to measure or transmit the data they record when measuring energy consumption, known as meter readings, owing to faulty measuring equipment or unreliable communication modules. Existing studies do not address successive and non-periodical missing meter readings. This paper proposes a method whereby missing readings observed at a node are estimated by using circuit theory principles that leverage the voltage and current data from adjacent nodes. A case study is used to demonstrate the ability of the proposed method to successfully estimate the missing readings over an entire day during which outages and unpredictable perturbations occurred.

  6. Placenta Percreta in First Trimester after Multiple Rounds of Failed Medical Management for a Missed Abortion

    Directory of Open Access Journals (Sweden)

    Jaimin Shah

    2017-01-01

    Full Text Available Background. The detection of a morbidly adherent placenta (MAP in the first trimester is rare. Risk factors such as multiparity, advanced maternal age, prior cesarean delivery, prior myomectomy, placenta previa, or previous uterine evacuation place patients at a higher risk for having abnormal placental implantation. If these patients have a first trimester missed abortion and fail medical management, it is important that providers have a heightened suspicion for a MAP. Case. A 24-year-old G4P3003 with 3 prior cesarean deliveries underwent multiple rounds of failed medical management for a missed abortion. She had a dilation and curettage that was complicated by a significant hemorrhage and ultimately required an urgent hysterectomy. Conclusion. When patients fail medical management for a missed abortion, providers need to assess the patient’s risk factors for a MAP. If risk factors are present, a series of specific evaluations should be triggered to rule out a MAP and help further guide management. Early diagnosis of a MAP allows providers to coordinate a multidisciplinary treatment approach and thoroughly counsel patients. Ensuring adequate resources and personnel at a tertiary hospital is essential to provide the highest quality of care and improve outcomes.

  7. Pragmatic criteria of the definition of neonatal near miss: a comparative study.

    Science.gov (United States)

    Kale, Pauline Lorena; Jorge, Maria Helena Prado de Mello; Laurenti, Ruy; Fonseca, Sandra Costa; Silva, Kátia Silveira da

    2017-12-04

    The objective of this study was to test the validity of the pragmatic criteria of the definitions of neonatal near miss, extending them throughout the infant period, and to estimate the indicators of perinatal care in public maternity hospitals. A cohort of live births from six maternity hospitals in the municipalities of São Paulo, Niterói, and Rio de Janeiro, Brazil, was carried out in 2011. We carried out interviews and checked prenatal cards and medical records. We compared the pragmatic criteria (birth weight, gestational age, and 5' Apgar score) of the definitions of near miss of Pileggi et al., Pileggi-Castro et al., Souza et al., and Silva et al. We calculated sensitivity, specificity (gold standard: infant mortality), percentage of deaths among newborns with life-threatening conditions, and rates of near miss, mortality, and severe outcomes per 1,000 live births. A total 7,315 newborns were analyzed (completeness of information > 99%). The sensitivity of the definition of Pileggi-Castro et al. was higher, resulting in a higher number of cases of near miss, Souza et al. presented lower value, and Pileggi et al. and de Silva et al. presented intermediate values. There is an increase in sensitivity when the period goes from 0-6 to 0-27 days, and there is a decrease when it goes to 0-364 days. Specificities were high (≥ 97%) and above sensitivities (54% to 77%). One maternity hospital in São Paulo and one in Niterói presented, respectively, the lowest and highest rates of infant mortality, near miss, and frequency of births with life-threatening conditions, regardless of the definition. The definitions of near miss based exclusively on pragmatic criteria are valid and can be used for monitoring purposes. Based on the perinatal literature, the cutoff points adopted by Silva et al. were more appropriate. Periodic studies could apply a more complete definition, incorporating clinical, laboratory, and management criteria, including congenital anomalies

  8. Fear of Missing Out, online social networking and mobile phone addiction : a latent profile approach

    OpenAIRE

    Fúster, Héctor; Chamarro Lusar, Andrés; Oberst, Úrsula E.

    2017-01-01

    Background and aims: Fear of missing out (FoMO) is described as a pervasive unpleasant sensation that others might be having rewarding experiences of which one is not part, as well as the desire to stay continually connected with what others are doing. It has shown to play an important mediating role in predicting negative outcomes of heavy use of these networks. The aim of the present study was to analyze the different profiles found among users. Methods: 5,280 Spanish speaking social media ...

  9. Fear of Missing Out, online social networking and mobile phone addiction: A latent profile approach

    OpenAIRE

    Fuster, Héctor; Chamarro, Andrés; Oberst, Ursula

    2017-01-01

    Fear of missing out (FoMO) is described as a pervasive, unpleasant sensation that others might be having rewarding experiences of which one is not part, as well as the desire to stay continually connected with what others are doing. It has been shown to play an important mediating role in predicting negative outcomes of heavy use of social networks. The aim of the present study was to analyze the different profiles found among users. 5,280 Spanish speaking social media users from ...

  10. ErythropoieSIS stimulating agent (ESA use is increased following missed dialysis sessions

    Directory of Open Access Journals (Sweden)

    T. Christopher Bond

    2012-06-01

    Missed session episodes result in significant increases in ESA utilization in the post-miss period, and also in total monthly ESA use. Such increases should be considered in any assessment of impact of missed sessions: both clinical and economic.

  11. A biclustering algorithm for binary matrices based on penalized Bernoulli likelihood

    KAUST Repository

    Lee, Seokho

    2013-01-31

    We propose a new biclustering method for binary data matrices using the maximum penalized Bernoulli likelihood estimation. Our method applies a multi-layer model defined on the logits of the success probabilities, where each layer represents a simple bicluster structure and the combination of multiple layers is able to reveal complicated, multiple biclusters. The method allows for non-pure biclusters, and can simultaneously identify the 1-prevalent blocks and 0-prevalent blocks. A computationally efficient algorithm is developed and guidelines are provided for specifying the tuning parameters, including initial values of model parameters, the number of layers, and the penalty parameters. Missing-data imputation can be handled in the EM framework. The method is tested using synthetic and real datasets and shows good performance. © 2013 Springer Science+Business Media New York.

  12. Reducing Misses and Near Misses Related to Multitasking on the Electronic Health Record: Observational Study and Qualitative Analysis.

    Science.gov (United States)

    Ratanawongsa, Neda; Matta, George Y; Bohsali, Fuad B; Chisolm, Margaret S

    2018-02-06

    Clinicians' use of electronic health record (EHR) systems while multitasking may increase the risk of making errors, but silent EHR system use may lower patient satisfaction. Delaying EHR system use until after patient visits may increase clinicians' EHR workload, stress, and burnout. We aimed to describe the perspectives of clinicians, educators, administrators, and researchers about misses and near misses that they felt were related to clinician multitasking while using EHR systems. This observational study was a thematic analysis of perspectives elicited from 63 continuing medical education (CME) participants during 2 workshops and 1 interactive lecture about challenges and strategies for relationship-centered communication during clinician EHR system use. The workshop elicited reflection about memorable times when multitasking EHR use was associated with "misses" (errors that were not caught at the time) or "near misses" (mistakes that were caught before leading to errors). We conducted qualitative analysis using an editing analysis style to identify codes and then select representative themes and quotes. All workshop participants shared stories of misses or near misses in EHR system ordering and documentation or patient-clinician communication, wondering about "misses we don't even know about." Risk factors included the computer's position, EHR system usability, note content and style, information overload, problematic workflows, systems issues, and provider and patient communication behaviors and expectations. Strategies to reduce multitasking EHR system misses included clinician transparency when needing silent EHR system use (eg, for prescribing), narrating EHR system use, patient activation during EHR system use, adapting visit organization and workflow, improving EHR system design, and improving team support and systems. CME participants shared numerous stories of errors and near misses in EHR tasks and communication that they felt related to EHR

  13. Missing data in clinical trials: control-based mean imputation and sensitivity analysis.

    Science.gov (United States)

    Mehrotra, Devan V; Liu, Fang; Permutt, Thomas

    2017-09-01

    In some randomized (drug versus placebo) clinical trials, the estimand of interest is the between-treatment difference in population means of a clinical endpoint that is free from the confounding effects of "rescue" medication (e.g., HbA1c change from baseline at 24 weeks that would be observed without rescue medication regardless of whether or when the assigned treatment was discontinued). In such settings, a missing data problem arises if some patients prematurely discontinue from the trial or initiate rescue medication while in the trial, the latter necessitating the discarding of post-rescue data. We caution that the commonly used mixed-effects model repeated measures analysis with the embedded missing at random assumption can deliver an exaggerated estimate of the aforementioned estimand of interest. This happens, in part, due to implicit imputation of an overly optimistic mean for "dropouts" (i.e., patients with missing endpoint data of interest) in the drug arm. We propose an alternative approach in which the missing mean for the drug arm dropouts is explicitly replaced with either the estimated mean of the entire endpoint distribution under placebo (primary analysis) or a sequence of increasingly more conservative means within a tipping point framework (sensitivity analysis); patient-level imputation is not required. A supplemental "dropout = failure" analysis is considered in which a common poor outcome is imputed for all dropouts followed by a between-treatment comparison using quantile regression. All analyses address the same estimand and can adjust for baseline covariates. Three examples and simulation results are used to support our recommendations. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Missing data imputation using statistical and machine learning methods in a real breast cancer problem.

    Science.gov (United States)

    Jerez, José M; Molina, Ignacio; García-Laencina, Pedro J; Alba, Emilio; Ribelles, Nuria; Martín, Miguel; Franco, Leonardo

    2010-10-01

    Missing data imputation is an important task in cases where it is crucial to use all available data and not discard records with missing values. This work evaluates the performance of several statistical and machine learning imputation methods that were used to predict recurrence in patients in an extensive real breast cancer data set. Imputation methods based on statistical techniques, e.g., mean, hot-deck and multiple imputation, and machine learning techniques, e.g., multi-layer perceptron (MLP), self-organisation maps (SOM) and k-nearest neighbour (KNN), were applied to data collected through the "El Álamo-I" project, and the results were then compared to those obtained from the listwise deletion (LD) imputation method. The database includes demographic, therapeutic and recurrence-survival information from 3679 women with operable invasive breast cancer diagnosed in 32 different hospitals belonging to the Spanish Breast Cancer Research Group (GEICAM). The accuracies of predictions on early cancer relapse were measured using artificial neural networks (ANNs), in which different ANNs were estimated using the data sets with imputed missing values. The imputation methods based on machine learning algorithms outperformed imputation statistical methods in the prediction of patient outcome. Friedman's test revealed a significant difference (p=0.0091) in the observed area under the ROC curve (AUC) values, and the pairwise comparison test showed that the AUCs for MLP, KNN and SOM were significantly higher (p=0.0053, p=0.0048 and p=0.0071, respectively) than the AUC from the LD-based prognosis model. The methods based on machine learning techniques were the most suited for the imputation of missing values and led to a significant enhancement of prognosis accuracy compared to imputation methods based on statistical procedures. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. DWARF GALAXY CLUSTERING AND MISSING SATELLITES

    International Nuclear Information System (INIS)

    Carlberg, R. G.; Sullivan, M.; Le Borgne, D.

    2009-01-01

    At redshifts around 0.1 the Canada-France-Hawaii Telescope Legacy Survey Deep fields contain some 6 x 10 4 galaxies spanning the mass range from 10 5 to 10 12 M sun . We measure the stellar mass dependence of the two-point correlation using angular measurements to largely bypass the errors, approximately 0.02 in the median, of the photometric redshifts. Inverting the power-law fits with Limber's equation we find that the autocorrelation length increases from a very low 0.4 h -1 Mpc at 10 5.5 M sun to the conventional 4.5 h -1 Mpc at 10 10.5 M sun . The power-law fit to the correlation function has a slope which increases from γ ≅ 1.6 at high mass to γ ≅ 2.3 at low mass. The spatial cross-correlation of dwarf galaxies with more massive galaxies shows fairly similar trends, with a steeper radial dependence at low mass than predicted in numerical simulations of subhalos within galaxy halos. To examine the issue of 'missing satellites' we combine the cross-correlation measurements with our estimates of the low-mass galaxy number density. We find on the average there are 60 ± 20 dwarfs in subhalos with M(total)>10 7 M sun for a typical Local Group M(total)/M(stars) = 30, corresponding to M/L V ≅ 100 for a galaxy with no recent star formation. The number of dwarfs per galaxy is about a factor of 2 larger than currently found for the Milky Way. Nevertheless, the average dwarf counts are about a factor of 30 below lambda cold dark matter (LCDM) simulation results. The divergence from LCDM predictions is one of the slope of the relation, approximately dN/dln M ≅ -0.5 rather than the predicted -0.9, not sudden onset at some characteristic scale. The dwarf galaxy star formation rates span the range from passive to bursting, which suggests that there are few completely dark halos.

  16. Automatic visual inspection of a missing split pin in the China railway high-speed.

    Science.gov (United States)

    Lu, Shengfang; Liu, Zhen

    2016-10-20

    The split pin (SP) on the caliper brake is a vital component of the brake system of a bogie traveling along the China railway high-speed (CRH), and the absence of the SP could cause serious train accidents. A new automatic visual inspection method is proposed for the quick and accurate detection of SP faults of the CRH. The proposed approach is based on the histogram of gradient (HOG) combined with the complete local binary pattern (CLBP). First, a fast pyramid template matching technique is presented for localizing the region of interest to reduce the searching scope. Under the multiresolution pyramid model for target localization, a coarse-to-fine strategy is employed to ensure that the recognizing speed of the SP for the entire image is increased significantly. Second, a hierarchical framework is adopted at the localizing and inspecting stages of the SP to automatically implement the inspection tasks. To increase the robustness to the outside complex illumination, the HOG feature for localizing the target and the CLBP feature for examining the state of the SP (i.e., missing or not-missing) are extracted in the Sobel gradient domain. The localization and recognition stages are both fulfilled through the use of their respective intersection kernel support vector machine classifiers and corresponding features. In conclusion, experimental results indicate that the inspection system achieves a high accuracy rate of more than 99.0% and a real-time speed, thus proving that the proposed method is effective for the fault inspection of the SP and can satisfy the requirements of CRH's actual application.

  17. The role of proxy information in missing data analysis.

    Science.gov (United States)

    Huang, Rong; Liang, Yuanyuan; Carrière, K C

    2005-10-01

    This article investigates the role of proxy data in dealing with the common problem of missing data in clinical trials using repeated measures designs. In an effort to avoid the missing data situation, some proxy information can be gathered. The question is how to treat proxy information, that is, is it always better to utilize proxy information when there are missing data? A model for repeated measures data with missing values is considered and a strategy for utilizing proxy information is developed. Then, simulations are used to compare the power of a test using proxy to simply utilizing all available data. It is concluded that using proxy information can be a useful alternative when such information is available. The implications for various clinical designs are also considered and a data collection strategy for efficiently estimating parameters is suggested.

  18. ATLAS event featuring two charm jets and missing energy

    CERN Multimedia

    ATLAS Collaboration

    2012-01-01

    Proton collision event in the ATLAS detector featuring two tagged charm jets and missing transverse energy. The zoomed view in the bottom right panel shows a displaced vertex of one of the c-tagged jets (marked in blue).

  19. Missing Links: Gender Equity in Science and Technology for ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Missing Links: Gender Equity in Science and Technology for Development. Book cover ... Gender Working Group of the United Nations Commission on Science and Technology for Development. Publisher(s): ... Knowledge. Innovation.

  20. 40 CFR 98.55 - Procedures for estimating missing data.

    Science.gov (United States)

    2010-07-01

    ... accounting purposes (such as sales records). (b) For missing values related to the performance test, including emission factors, production rate, and N2O concentration, you must conduct a new performance test...