Sample records for randomly selected general

  1. 47 CFR 1.1602 - Designation for random selection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Designation for random selection. 1.1602 Section 1.1602 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1602 Designation for random selection...

  2. 47 CFR 1.1602 - Designation for random selection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Designation for random selection. 1.1602 Section 1.1602 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1602 Designation for random selection...

  3. 47 CFR 1.1603 - Conduct of random selection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...

  4. 47 CFR 1.1603 - Conduct of random selection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...

  5. 47 CFR 1.1604 - Post-selection hearings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Post-selection hearings. 1.1604 Section 1.1604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1604 Post-selection hearings. (a) Following the random...

  6. 47 CFR 1.1604 - Post-selection hearings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Post-selection hearings. 1.1604 Section 1.1604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1604 Post-selection hearings. (a) Following the random...

  7. The Random-Threshold Generalized Unfolding Model and Its Application of Computerized Adaptive Testing

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Liu, Chen-Wei; Wu, Shiu-Lien

    2013-01-01

    The random-threshold generalized unfolding model (RTGUM) was developed by treating the thresholds in the generalized unfolding model as random effects rather than fixed effects to account for the subjective nature of the selection of categories in Likert items. The parameters of the new model can be estimated with the JAGS (Just Another Gibbs…

  8. Selective Influence through Conditional Independence.

    ERIC Educational Resources Information Center

    Dzhafarov, Ehtibar N.

    2003-01-01

    Presents a generalization and improvement for the definition proposed by E. Dzhafarov (2001) for selectiveness in the dependence of several random variables on several (sets of) external factors. This generalization links the notion of selective influence with that of conditional independence. (SLD)

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  10. Do bioclimate variables improve performance of climate envelope models?

    USGS Publications Warehouse

    Watling, James I.; Romañach, Stephanie S.; Bucklin, David N.; Speroterra, Carolina; Brandt, Laura A.; Pearlstine, Leonard G.; Mazzotti, Frank J.

    2012-01-01

    Climate envelope models are widely used to forecast potential effects of climate change on species distributions. A key issue in climate envelope modeling is the selection of predictor variables that most directly influence species. To determine whether model performance and spatial predictions were related to the selection of predictor variables, we compared models using bioclimate variables with models constructed from monthly climate data for twelve terrestrial vertebrate species in the southeastern USA using two different algorithms (random forests or generalized linear models), and two model selection techniques (using uncorrelated predictors or a subset of user-defined biologically relevant predictor variables). There were no differences in performance between models created with bioclimate or monthly variables, but one metric of model performance was significantly greater using the random forest algorithm compared with generalized linear models. Spatial predictions between maps using bioclimate and monthly variables were very consistent using the random forest algorithm with uncorrelated predictors, whereas we observed greater variability in predictions using generalized linear models.

  11. Site Selection in Experiments: A Follow-Up Evaluation of Site Recruitment in Two Scale-Up Studies

    ERIC Educational Resources Information Center

    Tipton, Elizabeth; Fellers, Lauren; Caverly, Sarah; Vaden-Kiernan, Michael; Borman, Geoffrey; Sullivan, Kate; Ruiz de Castillo, Veronica

    2015-01-01

    Randomized experiments are commonly used to evaluate if particular interventions improve student achievement. While these experiments can establish that a treatment actually "causes" changes, typically the participants are not randomly selected from a well-defined population and therefore the results do not readily generalize. Three…

  12. Random bits, true and unbiased, from atmospheric turbulence

    PubMed Central

    Marangon, Davide G.; Vallone, Giuseppe; Villoresi, Paolo

    2014-01-01

    Random numbers represent a fundamental ingredient for secure communications and numerical simulation as well as to games and in general to Information Science. Physical processes with intrinsic unpredictability may be exploited to generate genuine random numbers. The optical propagation in strong atmospheric turbulence is here taken to this purpose, by observing a laser beam after a 143 km free-space path. In addition, we developed an algorithm to extract the randomness of the beam images at the receiver without post-processing. The numbers passed very selective randomness tests for qualification as genuine random numbers. The extracting algorithm can be easily generalized to random images generated by different physical processes. PMID:24976499

  13. Improving Generalizations from Experiments Using Propensity Score Subclassification: Assumptions, Properties, and Contexts

    ERIC Educational Resources Information Center

    Tipton, Elizabeth

    2013-01-01

    As a result of the use of random assignment to treatment, randomized experiments typically have high internal validity. However, units are very rarely randomly selected from a well-defined population of interest into an experiment; this results in low external validity. Under nonrandom sampling, this means that the estimate of the sample average…

  14. The Effect of Different Modes of English Captioning on EFL Learners' General Listening Comprehension: Full Text vs. Keyword Captions

    ERIC Educational Resources Information Center

    Behroozizad, Sorayya; Majidi, Sudabeh

    2015-01-01

    This study investigated the effect of different modes of English captioning on EFL learners' general listening comprehension. To this end, forty-five intermediate-level learners were selected based on their scores on a standardized English proficiency test (PET) to carry out the study. Then, the selected participants were randomly assigned into…

  15. Application of random effects to the study of resource selection by animals

    USGS Publications Warehouse

    Gillies, C.S.; Hebblewhite, M.; Nielsen, S.E.; Krawchuk, M.A.; Aldridge, Cameron L.; Frair, J.L.; Saher, D.J.; Stevens, C.E.; Jerde, C.L.

    2006-01-01

    1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence.2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability.3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed.4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects.5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection.6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

  16. Application of random effects to the study of resource selection by animals.

    PubMed

    Gillies, Cameron S; Hebblewhite, Mark; Nielsen, Scott E; Krawchuk, Meg A; Aldridge, Cameron L; Frair, Jacqueline L; Saher, D Joanne; Stevens, Cameron E; Jerde, Christopher L

    2006-07-01

    1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence. 2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability. 3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed. 4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects. 5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection. 6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions limiting their generality. This approach will allow researchers to appropriately estimate marginal (population) and conditional (individual) responses, and account for complex grouping, unbalanced sample designs and autocorrelation.

  17. Key Aspects of Nucleic Acid Library Design for in Vitro Selection

    PubMed Central

    Vorobyeva, Maria A.; Davydova, Anna S.; Vorobjev, Pavel E.; Pyshnyi, Dmitrii V.; Venyaminova, Alya G.

    2018-01-01

    Nucleic acid aptamers capable of selectively recognizing their target molecules have nowadays been established as powerful and tunable tools for biospecific applications, be it therapeutics, drug delivery systems or biosensors. It is now generally acknowledged that in vitro selection enables one to generate aptamers to almost any target of interest. However, the success of selection and the affinity of the resulting aptamers depend to a large extent on the nature and design of an initial random nucleic acid library. In this review, we summarize and discuss the most important features of the design of nucleic acid libraries for in vitro selection such as the nature of the library (DNA, RNA or modified nucleotides), the length of a randomized region and the presence of fixed sequences. We also compare and contrast different randomization strategies and consider computer methods of library design and some other aspects. PMID:29401748

  18. 47 CFR 1.1621 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Definitions. 1.1621 Section 1.1621 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1621 Definitions. (a) Medium of mass communications means...

  19. 47 CFR 1.1621 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Definitions. 1.1621 Section 1.1621 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1621 Definitions. (a) Medium of mass communications means...

  20. 47 CFR 1.1623 - Probability calculation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Probability calculation. 1.1623 Section 1.1623 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1623 Probability calculation. (a) All calculations shall be...

  1. 47 CFR 1.1601 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Scope. 1.1601 Section 1.1601 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1601 Scope. The provisions of this subpart, and the provisions...

  2. 47 CFR 1.1601 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Scope. 1.1601 Section 1.1601 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1601 Scope. The provisions of this subpart, and the provisions...

  3. Classroom management programs for deaf children in state residential and large public schools.

    PubMed

    Wenkus, M; Rittenhouse, B; Dancer, J

    1999-12-01

    Personnel in 4 randomly selected state residential schools for the deaf and 3 randomly selected large public schools with programs for the deaf were surveyed to assess the types of management or disciplinary programs and strategies currently in use with deaf students and the rated effectiveness of such programs. Several behavioral management programs were identified by respondents, with Assertive Discipline most often listed. Ratings of program effectiveness were generally above average on a number of qualitative criteria.

  4. Cavity tree selection by red-cockaded woodpeckers in relation to tree age

    Treesearch

    D. Craig Rudolph; Richard N. Conner

    1991-01-01

    We aged over 1350 Red-cockaded Woodpecker (Picoides borealis) cavity trees and a comparable number of randomly selected trees. Resulting data strongly support the hypothesis that Red-cockaded Woodpeckers preferentially select older trees. Ages of recently initiated cavity trees in the Texas study areas generally were similar to those of cavity trees...

  5. 47 CFR 1.9060 - Amendments, waivers, and dismissals affecting spectrum leasing notifications and applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... spectrum leasing notifications and applications. 1.9060 Section 1.9060 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9060 Amendments, waivers, and dismissals affecting spectrum leasing...

  6. 47 CFR 1.9060 - Amendments, waivers, and dismissals affecting spectrum leasing notifications and applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... spectrum leasing notifications and applications. 1.9060 Section 1.9060 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9060 Amendments, waivers, and dismissals affecting spectrum leasing...

  7. 47 CFR 1.9060 - Amendments, waivers, and dismissals affecting spectrum leasing notifications and applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... spectrum leasing notifications and applications. 1.9060 Section 1.9060 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9060 Amendments, waivers, and dismissals affecting spectrum leasing...

  8. Universal statistics of selected values

    NASA Astrophysics Data System (ADS)

    Smerlak, Matteo; Youssef, Ahmed

    2017-03-01

    Selection, the tendency of some traits to become more frequent than others under the influence of some (natural or artificial) agency, is a key component of Darwinian evolution and countless other natural and social phenomena. Yet a general theory of selection, analogous to the Fisher-Tippett-Gnedenko theory of extreme events, is lacking. Here we introduce a probabilistic definition of selection and show that selected values are attracted to a universal family of limiting distributions which generalize the log-normal distribution. The universality classes and scaling exponents are determined by the tail thickness of the random variable under selection. Our results provide a possible explanation for skewed distributions observed in diverse contexts where selection plays a key role, from molecular biology to agriculture and sport.

  9. Why Students Are Hostile to Free Enterprise

    ERIC Educational Resources Information Center

    Kilpatrick, James L.

    1975-01-01

    A Gallup study is described, which was commissioned by Oklahoma State Christian College regarding the philosophical orientation of college students generally (liberal or conservative). The author presents selected findings and concludes that students in the national random sample are ignorant of industrial life and generally hostile toward the…

  10. 47 CFR 1.9047 - Special provisions relating to leases of educational broadband service spectrum.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... educational broadband service spectrum. 1.9047 Section 1.9047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9047 Special provisions relating to leases of educational broadband service spectrum...

  11. 47 CFR 1.9047 - Special provisions relating to leases of educational broadband service spectrum.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... educational broadband service spectrum. 1.9047 Section 1.9047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9047 Special provisions relating to leases of educational broadband service spectrum...

  12. 47 CFR 1.9047 - Special provisions relating to leases of educational broadband service spectrum.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... educational broadband service spectrum. 1.9047 Section 1.9047 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9047 Special provisions relating to leases of educational broadband service spectrum...

  13. The Consequences of Teenage Childbearing: Consistent Estimates When Abortion Makes Miscarriage Nonrandom*

    PubMed Central

    Ashcraft, Adam; Fernández-Val, Iván; Lang, Kevin

    2012-01-01

    Miscarriage, even if biologically random, is not socially random. Willingness to abort reduces miscarriage risk. Because abortions are favorably selected among pregnant teens, those miscarrying are less favorably selected than those giving birth or aborting but more favorably selected than those giving birth. Therefore, using miscarriage as an instrument is biased towards a benign view of teen motherhood while OLS on just those giving birth or miscarrying has the opposite bias. We derive a consistent estimator that reduces to a weighted average of OLS and IV when outcomes are independent of abortion timing. Estimated effects are generally adverse but modest. PMID:24443589

  14. 47 CFR 1.915 - General application requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and... (b) of this section, for all Wireless Radio Services, station licenses, as defined in section 308(a...

  15. 47 CFR 1.915 - General application requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and... (b) of this section, for all Wireless Radio Services, station licenses, as defined in section 308(a...

  16. 47 CFR 1.915 - General application requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and... (b) of this section, for all Wireless Radio Services, station licenses, as defined in section 308(a...

  17. 47 CFR 1.9048 - Special provisions relating to spectrum leasing arrangements involving licensees in the Public...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Special provisions relating to spectrum leasing... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9048 Special provisions relating to spectrum leasing...

  18. 47 CFR 1.9055 - Assignment of file numbers to spectrum leasing notifications and applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Assignment of file numbers to spectrum leasing... GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9055 Assignment of file numbers to spectrum leasing notifications and applications. Spectrum...

  19. 47 CFR 1.9055 - Assignment of file numbers to spectrum leasing notifications and applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Assignment of file numbers to spectrum leasing... GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9055 Assignment of file numbers to spectrum leasing notifications and applications. Spectrum...

  20. 47 CFR 1.9048 - Special provisions relating to spectrum leasing arrangements involving licensees in the Public...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Special provisions relating to spectrum leasing... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9048 Special provisions relating to spectrum leasing...

  1. 47 CFR 1.9055 - Assignment of file numbers to spectrum leasing notifications and applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Assignment of file numbers to spectrum leasing... GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9055 Assignment of file numbers to spectrum leasing notifications and applications. Spectrum...

  2. 47 CFR 1.9048 - Special provisions relating to spectrum leasing arrangements involving licensees in the Public...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Special provisions relating to spectrum leasing... FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9048 Special provisions relating to spectrum leasing...

  3. Teacher's and Students' Beliefs on English for General Academic Purposes: The Case of Iranian University Students

    ERIC Educational Resources Information Center

    Kojour, Masoud Kermani; Heirati, Javad Kia

    2015-01-01

    This study was framed in the sociocultural theory to look into the evolution of L2 learners' beliefs about the general English course during a term. One hundred ninety-eight male and female university students and their general English course teacher were randomly selected as the participants of the study. Data were gathered through the…

  4. 7 CFR 767.151 - General requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... beginning farmers or socially disadvantaged farmersto purchase real property. (b) The Agency will advertise...) Random selection is final and not subject to administrative appeal. (d) If there are no offers from...

  5. CURE-SMOTE algorithm and hybrid algorithm for feature selection and parameter optimization based on random forests.

    PubMed

    Ma, Li; Fan, Suohai

    2017-03-14

    The random forests algorithm is a type of classifier with prominent universality, a wide application range, and robustness for avoiding overfitting. But there are still some drawbacks to random forests. Therefore, to improve the performance of random forests, this paper seeks to improve imbalanced data processing, feature selection and parameter optimization. We propose the CURE-SMOTE algorithm for the imbalanced data classification problem. Experiments on imbalanced UCI data reveal that the combination of Clustering Using Representatives (CURE) enhances the original synthetic minority oversampling technique (SMOTE) algorithms effectively compared with the classification results on the original data using random sampling, Borderline-SMOTE1, safe-level SMOTE, C-SMOTE, and k-means-SMOTE. Additionally, the hybrid RF (random forests) algorithm has been proposed for feature selection and parameter optimization, which uses the minimum out of bag (OOB) data error as its objective function. Simulation results on binary and higher-dimensional data indicate that the proposed hybrid RF algorithms, hybrid genetic-random forests algorithm, hybrid particle swarm-random forests algorithm and hybrid fish swarm-random forests algorithm can achieve the minimum OOB error and show the best generalization ability. The training set produced from the proposed CURE-SMOTE algorithm is closer to the original data distribution because it contains minimal noise. Thus, better classification results are produced from this feasible and effective algorithm. Moreover, the hybrid algorithm's F-value, G-mean, AUC and OOB scores demonstrate that they surpass the performance of the original RF algorithm. Hence, this hybrid algorithm provides a new way to perform feature selection and parameter optimization.

  6. How Special Are Teachers of Specialized Schools? Assessing Self-Confidence Levels in the Technology Domain

    ERIC Educational Resources Information Center

    Çatma, Zehra; Corlu, Mehmet Sencer

    2016-01-01

    This study investigates whether specialized high school mathematics teachers, chosen to educate selected students, are mentally ready to integrate Fatih project technologies into their teaching. Forty mathematics teachers from randomly selected specialized and general high schools in Ankara responded to a survey comprising 31 items grouped under…

  7. Can randomization be informative?

    NASA Astrophysics Data System (ADS)

    Pereira, Carlos A. B.; Campos, Thiago F.; Silva, Gustavo M.; Wechsler, Sergio

    2012-10-01

    In this paper the Pair of Siblings Paradox introduced by Pereira [1] is extended by considering more than two children and more than one child observed for gender. We follow the same lines of Wechsler et al. [2] that generalizes the three prisoners' dilemma, introduced by Gardner [3]. This paper's conjecture is that the Pair of Siblings and the Three Prisoners dilemma are dual paradoxes. Looking at possible likelihoods, the sure (randomized) selection for the former is non informative (informative), the opposite that holds for the latter. This situation is maintained for generalizations. Non informative likelihood here means that prior and posterior are equal.

  8. 47 CFR 1.824 - Random selection procedures for Multichannel Multipoint Distribution Service and Multipoint...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... an ownership interest of more than 50 percent in the media of mass communication whose service areas... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Complaints, Applications, Tariffs...

  9. Vermont transportation survey

    DOT National Transportation Integrated Search

    1994-01-01

    A travel survey conducted in Spring 1994 in Vermont is included in this report. The actual survey and accompanying cover letter sent to random households is the focus of this report. General information, such as why households were selected, the impo...

  10. Prediction of Baseflow Index of Catchments using Machine Learning Algorithms

    NASA Astrophysics Data System (ADS)

    Yadav, B.; Hatfield, K.

    2017-12-01

    We present the results of eight machine learning techniques for predicting the baseflow index (BFI) of ungauged basins using a surrogate of catchment scale climate and physiographic data. The tested algorithms include ordinary least squares, ridge regression, least absolute shrinkage and selection operator (lasso), elasticnet, support vector machine, gradient boosted regression trees, random forests, and extremely randomized trees. Our work seeks to identify the dominant controls of BFI that can be readily obtained from ancillary geospatial databases and remote sensing measurements, such that the developed techniques can be extended to ungauged catchments. More than 800 gauged catchments spanning the continental United States were selected to develop the general methodology. The BFI calculation was based on the baseflow separated from daily streamflow hydrograph using HYSEP filter. The surrogate catchment attributes were compiled from multiple sources including digital elevation model, soil, landuse, climate data, other publicly available ancillary and geospatial data. 80% catchments were used to train the ML algorithms, and the remaining 20% of the catchments were used as an independent test set to measure the generalization performance of fitted models. A k-fold cross-validation using exhaustive grid search was used to fit the hyperparameters of each model. Initial model development was based on 19 independent variables, but after variable selection and feature ranking, we generated revised sparse models of BFI prediction that are based on only six catchment attributes. These key predictive variables selected after the careful evaluation of bias-variance tradeoff include average catchment elevation, slope, fraction of sand, permeability, temperature, and precipitation. The most promising algorithms exceeding an accuracy score (r-square) of 0.7 on test data include support vector machine, gradient boosted regression trees, random forests, and extremely randomized trees. Considering both the accuracy and the computational complexity of these algorithms, we identify the extremely randomized trees as the best performing algorithm for BFI prediction in ungauged basins.

  11. Variable Selection in the Presence of Missing Data: Imputation-based Methods.

    PubMed

    Zhao, Yize; Long, Qi

    2017-01-01

    Variable selection plays an essential role in regression analysis as it identifies important variables that associated with outcomes and is known to improve predictive accuracy of resulting models. Variable selection methods have been widely investigated for fully observed data. However, in the presence of missing data, methods for variable selection need to be carefully designed to account for missing data mechanisms and statistical techniques used for handling missing data. Since imputation is arguably the most popular method for handling missing data due to its ease of use, statistical methods for variable selection that are combined with imputation are of particular interest. These methods, valid used under the assumptions of missing at random (MAR) and missing completely at random (MCAR), largely fall into three general strategies. The first strategy applies existing variable selection methods to each imputed dataset and then combine variable selection results across all imputed datasets. The second strategy applies existing variable selection methods to stacked imputed datasets. The third variable selection strategy combines resampling techniques such as bootstrap with imputation. Despite recent advances, this area remains under-developed and offers fertile ground for further research.

  12. Influence of Head Teachers' General and Instructional Supervisory Practices on Teachers' Work Performance in Secondary Schools in Entebbe Municipality, Wakiso District, Uganda

    ERIC Educational Resources Information Center

    Jared, Nzabonimpa Buregeya

    2011-01-01

    The study examined the Influence of Secondary School Head Teachers' General and Instructional Supervisory Practices on Teachers' Work Performance. Qualitative and qualitative methods with a descriptive-correlational research approach were used in the study. Purposive sampling technique alongside random sampling technique was used to select the…

  13. 47 CFR 1.955 - Termination of authorizations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Termination of authorizations. 1.955 Section 1.955 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and...

  14. 47 CFR 1.955 - Termination of authorizations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Termination of authorizations. 1.955 Section 1.955 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and...

  15. 47 CFR 1.926 - Application processing; initial procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Application processing; initial procedures. 1.926 Section 1.926 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements...

  16. 47 CFR 1.926 - Application processing; initial procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Application processing; initial procedures. 1.926 Section 1.926 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements...

  17. 47 CFR 1.955 - Termination of authorizations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Termination of authorizations. 1.955 Section 1.955 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and...

  18. 47 CFR 1.926 - Application processing; initial procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Application processing; initial procedures. 1.926 Section 1.926 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements...

  19. Random forest feature selection approach for image segmentation

    NASA Astrophysics Data System (ADS)

    Lefkovits, László; Lefkovits, Szidónia; Emerich, Simina; Vaida, Mircea Florin

    2017-03-01

    In the field of image segmentation, discriminative models have shown promising performance. Generally, every such model begins with the extraction of numerous features from annotated images. Most authors create their discriminative model by using many features without using any selection criteria. A more reliable model can be built by using a framework that selects the important variables, from the point of view of the classification, and eliminates the unimportant once. In this article we present a framework for feature selection and data dimensionality reduction. The methodology is built around the random forest (RF) algorithm and its variable importance evaluation. In order to deal with datasets so large as to be practically unmanageable, we propose an algorithm based on RF that reduces the dimension of the database by eliminating irrelevant features. Furthermore, this framework is applied to optimize our discriminative model for brain tumor segmentation.

  20. 47 CFR 1.2110 - Designated entities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection... company” as defined by the Communications Act; and (iii) The applicant (or the controlling interest... office space and/or employees and/or other facilities with another concern, particularly where such...

  1. 47 CFR 1.2110 - Designated entities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection... company” as defined by the Communications Act; and (iii) The applicant (or the controlling interest... office space and/or employees and/or other facilities with another concern, particularly where such...

  2. 47 CFR 1.2110 - Designated entities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection... company” as defined by the Communications Act; and (iii) The applicant (or the controlling interest... office space and/or employees and/or other facilities with another concern, particularly where such...

  3. 47 CFR 1.1703 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Cable... control of entities holding authorizations. (b) Authorization. A written instrument issued by the FCC conveying authority to operate, for a specified period, a station in the Cable Television Relay Service. In...

  4. 47 CFR 1.1703 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Cable... control of entities holding authorizations. (b) Authorization. A written instrument issued by the FCC conveying authority to operate, for a specified period, a station in the Cable Television Relay Service. In...

  5. 47 CFR 1.1703 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Cable... control of entities holding authorizations. (b) Authorization. A written instrument issued by the FCC conveying authority to operate, for a specified period, a station in the Cable Television Relay Service. In...

  6. 47 CFR 1.956 - Settlement conferences.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Settlement conferences. 1.956 Section 1.956 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.956...

  7. 47 CFR 1.956 - Settlement conferences.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Settlement conferences. 1.956 Section 1.956 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.956...

  8. 47 CFR 1.956 - Settlement conferences.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Settlement conferences. 1.956 Section 1.956 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.956...

  9. 47 CFR 1.958 - Distance computation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Distance computation. 1.958 Section 1.958 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.958...

  10. 47 CFR 1.958 - Distance computation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Distance computation. 1.958 Section 1.958 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.958...

  11. 47 CFR 1.958 - Distance computation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Distance computation. 1.958 Section 1.958 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.958...

  12. 47 CFR 1.2209 - Disbursement of incentive payments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Disbursement of incentive payments. 1.2209 Section 1.2209 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Competitive Bidding Proceedings Broadcast Television Spectrum Reverse Auction § 1...

  13. 47 CFR 1.911 - Station files.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Station files. 1.911 Section 1.911 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.911...

  14. 47 CFR 1.911 - Station files.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Station files. 1.911 Section 1.911 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.911...

  15. 47 CFR 1.911 - Station files.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Station files. 1.911 Section 1.911 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.911...

  16. Simulating the component counts of combinatorial structures.

    PubMed

    Arratia, Richard; Barbour, A D; Ewens, W J; Tavaré, Simon

    2018-02-09

    This article describes and compares methods for simulating the component counts of random logarithmic combinatorial structures such as permutations and mappings. We exploit the Feller coupling for simulating permutations to provide a very fast method for simulating logarithmic assemblies more generally. For logarithmic multisets and selections, this approach is replaced by an acceptance/rejection method based on a particular conditioning relationship that represents the distribution of the combinatorial structure as that of independent random variables conditioned on a weighted sum. We show how to improve its acceptance rate. We illustrate the method by estimating the probability that a random mapping has no repeated component sizes, and establish the asymptotic distribution of the difference between the number of components and the number of distinct component sizes for a very general class of logarithmic structures. Copyright © 2018. Published by Elsevier Inc.

  17. 47 CFR 1.947 - Modification of licenses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947...

  18. 47 CFR 1.927 - Amendment of applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Amendment of applications. 1.927 Section 1.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.927...

  19. 47 CFR 1.927 - Amendment of applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Amendment of applications. 1.927 Section 1.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.927...

  20. 47 CFR 1.947 - Modification of licenses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947...

  1. 47 CFR 1.935 - Agreements to dismiss applications, amendments or pleadings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Agreements to dismiss applications, amendments or pleadings. 1.935 Section 1.935 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings...

  2. 47 CFR 1.935 - Agreements to dismiss applications, amendments or pleadings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Agreements to dismiss applications, amendments or pleadings. 1.935 Section 1.935 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings...

  3. 47 CFR 1.935 - Agreements to dismiss applications, amendments or pleadings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Agreements to dismiss applications, amendments or pleadings. 1.935 Section 1.935 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings...

  4. 47 CFR 1.939 - Petitions to deny.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Petitions to deny. 1.939 Section 1.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.939...

  5. 47 CFR 1.927 - Amendment of applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Amendment of applications. 1.927 Section 1.927 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.927...

  6. 47 CFR 1.947 - Modification of licenses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947...

  7. 47 CFR 1.939 - Petitions to deny.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Petitions to deny. 1.939 Section 1.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.939...

  8. 47 CFR 1.939 - Petitions to deny.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Petitions to deny. 1.939 Section 1.939 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.939...

  9. 47 CFR 1.10001 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... stamps your payment as received. Pay by online credit card (through IBFS) The date your online credit... Proposed Frequencies in the United States officially filed the moment you file them through IBFS. The... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection...

  10. 47 CFR 1.10001 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... stamps your payment as received. Pay by online credit card (through IBFS) The date your online credit... Proposed Frequencies in the United States officially filed the moment you file them through IBFS. The... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection...

  11. 47 CFR 1.10001 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... stamps your payment as received. Pay by online credit card (through IBFS) The date your online credit... Proposed Frequencies in the United States officially filed the moment you file them through IBFS. The... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection...

  12. Effect of expanding medicaid for parents on children's health insurance coverage: lessons from the Oregon experiment.

    PubMed

    DeVoe, Jennifer E; Marino, Miguel; Angier, Heather; O'Malley, Jean P; Crawford, Courtney; Nelson, Christine; Tillotson, Carrie J; Bailey, Steffani R; Gallia, Charles; Gold, Rachel

    2015-01-01

    In the United States, health insurance is not universal. Observational studies show an association between uninsured parents and children. This association persisted even after expansions in child-only public health insurance. Oregon's randomized Medicaid expansion for adults, known as the Oregon Experiment, created a rare opportunity to assess causality between parent and child coverage. To estimate the effect on a child's health insurance coverage status when (1) a parent randomly gains access to health insurance and (2) a parent obtains coverage. Oregon Experiment randomized natural experiment assessing the results of Oregon's 2008 Medicaid expansion. We used generalized estimating equation models to examine the longitudinal effect of a parent randomly selected to apply for Medicaid on their child's Medicaid or Children's Health Insurance Program (CHIP) coverage (intent-to-treat analyses). We used per-protocol analyses to understand the impact on children's coverage when a parent was randomly selected to apply for and obtained Medicaid. Participants included 14409 children aged 2 to 18 years whose parents participated in the Oregon Experiment. For intent-to-treat analyses, the date a parent was selected to apply for Medicaid was considered the date the child was exposed to the intervention. In per-protocol analyses, exposure was defined as whether a selected parent obtained Medicaid. Children's Medicaid or CHIP coverage, assessed monthly and in 6-month intervals relative to their parent's selection date. In the immediate period after selection, children whose parents were selected to apply significantly increased from 3830 (61.4%) to 4152 (66.6%) compared with a nonsignificant change from 5049 (61.8%) to 5044 (61.7%) for children whose parents were not selected to apply. Children whose parents were randomly selected to apply for Medicaid had 18% higher odds of being covered in the first 6 months after parent's selection compared with children whose parents were not selected (adjusted odds ratio [AOR]=1.18; 95% CI, 1.10-1.27). The effect remained significant during months 7 to 12 (AOR=1.11; 95% CI, 1.03-1.19); months 13 to 18 showed a positive but not significant effect (AOR=1.07; 95% CI, 0.99-1.14). Children whose parents were selected and obtained coverage had more than double the odds of having coverage compared with children whose parents were not selected and did not gain coverage (AOR=2.37; 95% CI, 2.14-2.64). Children's odds of having Medicaid or CHIP coverage increased when their parents were randomly selected to apply for Medicaid. Children whose parents were selected and subsequently obtained coverage benefited most. This study demonstrates a causal link between parents' access to Medicaid coverage and their children's coverage.

  13. Crime Victimization in Adults With Severe Mental Illness

    PubMed Central

    Teplin, Linda A.; McClelland, Gary M.; Abram, Karen M.; Weiner, Dana A.

    2006-01-01

    Context Since deinstitutionalization, most persons with severe mental illness (SMI) now live in the community, where they are at great risk for crime victimization. Objectives To determine the prevalence and incidence of crime victimization among persons with SMI by sex, race/ethnicity, and age, and to compare rates with general population data (the National Crime Victimization Survey), controlling for income and demographic differences between the samples. Design Epidemiologic study of persons in treatment. Independent master’s-level clinical research interviewers administered the National Crime Victimization Survey to randomly selected patients sampled from 16 randomly selected mental health agencies. Setting Sixteen agencies providing outpatient, day, and residential treatment to persons with SMI in Chicago, Ill. Participants Randomly selected, stratified sample of 936 patients aged 18 or older (483 men, 453 women) who were African American (n = 329), non-Hispanic white (n = 321), Hispanic (n = 270), or other race/ethnicity (n = 22). The comparison group comprised 32449 participants in the National Crime Victimization Survey. Main Outcome Measure National Crime Victimization Survey, developed by the Bureau of Justice Statistics. Results More than one quarter of persons with SMI had been victims of a violent crime in the past year, a rate more than 11 times higher than the general population rates even after controlling for demographic differences between the 2 samples (P<.001). The annual incidence of violent crime in the SMI sample (168.2 incidents per 1000 persons) is more than 4 times higher than the general population rates (39.9 incidents per 1000 persons) (P<.001). Depending on the type of violent crime (rape/sexual assault, robbery, assault, and their subcategories), prevalence was 6 to 23 times greater among persons with SMI than among the general population. Conclusions Crime victimization is a major public health problem among persons with SMI who are treated in the community. We recommend directions for future research, propose modifications in public policy, and suggest how the mental health system can respond to reduce victimization and its consequences. PMID:16061769

  14. Crime victimization in adults with severe mental illness: comparison with the National Crime Victimization Survey.

    PubMed

    Teplin, Linda A; McClelland, Gary M; Abram, Karen M; Weiner, Dana A

    2005-08-01

    Since deinstitutionalization, most persons with severe mental illness (SMI) now live in the community, where they are at great risk for crime victimization. To determine the prevalence and incidence of crime victimization among persons with SMI by sex, race/ethnicity, and age, and to compare rates with general population data (the National Crime Victimization Survey), controlling for income and demographic differences between the samples. Epidemiologic study of persons in treatment. Independent master's-level clinical research interviewers administered the National Crime Victimization Survey to randomly selected patients sampled from 16 randomly selected mental health agencies. Sixteen agencies providing outpatient, day, and residential treatment to persons with SMI in Chicago, Ill. Randomly selected, stratified sample of 936 patients aged 18 or older (483 men, 453 women) who were African American (n = 329), non-Hispanic white (n = 321), Hispanic (n = 270), or other race/ethnicity (n = 22). The comparison group comprised 32 449 participants in the National Crime Victimization Survey. National Crime Victimization Survey, developed by the Bureau of Justice Statistics. More than one quarter of persons with SMI had been victims of a violent crime in the past year, a rate more than 11 times higher than the general population rates even after controlling for demographic differences between the 2 samples (P<.001). The annual incidence of violent crime in the SMI sample (168.2 incidents per 1000 persons) is more than 4 times higher than the general population rates (39.9 incidents per 1000 persons) (P<.001). Depending on the type of violent crime (rape/sexual assault, robbery, assault, and their subcategories), prevalence was 6 to 23 times greater among persons with SMI than among the general population. Crime victimization is a major public health problem among persons with SMI who are treated in the community. We recommend directions for future research, propose modifications in public policy, and suggest how the mental health system can respond to reduce victimization and its consequences.

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

    PubMed Central

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

    2007-01-01

    Background Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods. Methods We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision. Application We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population. Conclusion This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be advantageous to choose clusters using reasoned hypotheses, based on both probability and geographical approaches, in contrast to a conventional, random cluster selection strategy. PMID:17543100

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

    PubMed

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

    2007-06-01

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

  17. A Generalization Strategy for Discrete Area Feature by Using Stroke Grouping and Polarization Transportation Selection

    NASA Astrophysics Data System (ADS)

    Wang, Xiao; Burghardt, Dirk

    2018-05-01

    This paper presents a new strategy for the generalization of discrete area features by using stroke grouping method and polarization transportation selection. The mentioned stroke is constructed on derive of the refined proximity graph of area features, and the refinement is under the control of four constraints to meet different grouping requirements. The area features which belong to the same stroke are detected into the same group. The stroke-based strategy decomposes the generalization process into two sub-processes by judging whether the area features related to strokes or not. For the area features which belong to the same one stroke, they normally present a linear like pat-tern, and in order to preserve this kind of pattern, typification is chosen as the operator to implement the generalization work. For the remaining area features which are not related by strokes, they are still distributed randomly and discretely, and the selection is chosen to conduct the generalization operation. For the purpose of retaining their original distribution characteristic, a Polarization Transportation (PT) method is introduced to implement the selection operation. Buildings and lakes are selected as the representatives of artificial area feature and natural area feature respectively to take the experiments. The generalized results indicate that by adopting this proposed strategy, the original distribution characteristics of building and lake data can be preserved, and the visual perception is pre-served as before.

  18. 47 CFR 1.902 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Scope. 1.902 Section 1.902 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Scope and Authority § 1.902 Scope. In case of any conflict between...

  19. 47 CFR 1.902 - Scope.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Scope. 1.902 Section 1.902 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Scope and Authority § 1.902 Scope. In case of any conflict between...

  20. 47 CFR 1.902 - Scope.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Scope. 1.902 Section 1.902 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and Proceedings Scope and Authority § 1.902 Scope. In case of any conflict between...

  1. 47 CFR 1.2001 - Purpose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Purpose. 1.2001 Section 1.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Implementation of the Anti-Drug Abuse Act of 1988 § 1.2001 Purpose. To determine eligibility for professional and...

  2. 47 CFR 1.2001 - Purpose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Purpose. 1.2001 Section 1.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Implementation of the Anti-Drug Abuse Act of 1988 § 1.2001 Purpose. To determine eligibility for professional and...

  3. 47 CFR 1.2001 - Purpose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Purpose. 1.2001 Section 1.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Implementation of the Anti-Drug Abuse Act of 1988 § 1.2001 Purpose. To determine eligibility for professional and...

  4. Genetic variation maintained in multilocus models of additive quantitative traits under stabilizing selection.

    PubMed Central

    Bürger, R; Gimelfarb, A

    1999-01-01

    Stabilizing selection for an intermediate optimum is generally considered to deplete genetic variation in quantitative traits. However, conflicting results from various types of models have been obtained. While classical analyses assuming a large number of independent additive loci with individually small effects indicated that no genetic variation is preserved under stabilizing selection, several analyses of two-locus models showed the contrary. We perform a complete analysis of a generalization of Wright's two-locus quadratic-optimum model and investigate numerically the ability of quadratic stabilizing selection to maintain genetic variation in additive quantitative traits controlled by up to five loci. A statistical approach is employed by choosing randomly 4000 parameter sets (allelic effects, recombination rates, and strength of selection) for a given number of loci. For each parameter set we iterate the recursion equations that describe the dynamics of gamete frequencies starting from 20 randomly chosen initial conditions until an equilibrium is reached, record the quantities of interest, and calculate their corresponding mean values. As the number of loci increases from two to five, the fraction of the genome expected to be polymorphic declines surprisingly rapidly, and the loci that are polymorphic increasingly are those with small effects on the trait. As a result, the genetic variance expected to be maintained under stabilizing selection decreases very rapidly with increased number of loci. The equilibrium structure expected under stabilizing selection on an additive trait differs markedly from that expected under selection with no constraints on genotypic fitness values. The expected genetic variance, the expected polymorphic fraction of the genome, as well as other quantities of interest, are only weakly dependent on the selection intensity and the level of recombination. PMID:10353920

  5. Headache, snoring and sleep apnoea.

    PubMed

    Ulfberg, J; Carter, N; Talbäck, M; Edling, C

    1996-09-01

    To evaluate reported headache prevalence among the general population and patients suffering from snoring and obstructive sleep apnoea syndrome (OSAS), a cross-sectional study was performed among those aged 30-64 years residing in Kopparberg county in central Sweden. Consecutive patients referred to the sleep laboratory in the catchment area who fulfilled objective diagnostic criteria (snorers = 448, OSAS = 324) and a random sample of the general population (n = 583) responded to the same questionnaire. Patients were selected following sleep apnoea screening with 100% specificity for both OSAS and snoring. Responders from the general population were divided into snorers or non-snorers on the basis of self-report. To validate the self-report question on snoring in the questionnaire, 50 males and 49 females, randomly selected from the sample of the general population, underwent sleep apnoea screening in their homes. Headache among both men and women was found to be more prevalent among heavy snorers and OSAS patients compared with the control group. Morning headache, in particular, was at least three times more common among male and female heavy snorers and OSAS patients then among the general population. Headache in the control group was more common among snorers than non-snorers. Among responders, 5% of the general population reported experiencing headache often or very often upon awakening. For the heavy snoring and OSAS groups, 18% reported experiencing headache often or very often upon awakening. The results indicate that headache is common among heavy snorers and OSAS patients regardless of gender.

  6. 10 CFR 431.383 - Enforcement process for electric motors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... general purpose electric motor of equivalent electrical design and enclosure rather than replacing the... equivalent electrical design and enclosure rather than machining and attaching an endshield. ... sample of up to 20 units will then be randomly selected from one or more subdivided groups within the...

  7. The Effects of Teaching Descriptive Geometry in General Engineering 103 on Spatial Relations Tests Scores.

    ERIC Educational Resources Information Center

    Stallings, William M.

    It was hypothesized that instruction in descriptive geometry produces an increase in SRT scores. The resultant data do not firmly support this hypothesis. It is suggested that this study be replicated with the use of randomly selected control groups. (MS)

  8. 47 CFR 1.925 - Waivers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Waivers. 1.925 Section 1.925 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio... applications in the Wireless Radio Services must be filed on FCC Form 601, 603, or 605. (2) Requests for waiver...

  9. 47 CFR 1.925 - Waivers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Waivers. 1.925 Section 1.925 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio... applications in the Wireless Radio Services must be filed on FCC Form 601, 603, or 605. (2) Requests for waiver...

  10. 47 CFR 1.925 - Waivers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Waivers. 1.925 Section 1.925 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio... applications in the Wireless Radio Services must be filed on FCC Form 601, 603, or 605. (2) Requests for waiver...

  11. 47 CFR 1.9040 - Contractual requirements applicable to spectrum leasing arrangements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Contractual requirements applicable to spectrum... PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9040 Contractual requirements applicable to spectrum leasing arrangements. (a) Agreements between licensees and...

  12. 47 CFR 1.9040 - Contractual requirements applicable to spectrum leasing arrangements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Contractual requirements applicable to spectrum... PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9040 Contractual requirements applicable to spectrum leasing arrangements. (a) Agreements between licensees and...

  13. 47 CFR 1.9040 - Contractual requirements applicable to spectrum leasing arrangements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Contractual requirements applicable to spectrum... PRACTICE AND PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9040 Contractual requirements applicable to spectrum leasing arrangements. (a) Agreements between licensees and...

  14. Close woods utilization commonly practiced in Delaware

    Treesearch

    Wayne G. Banks

    1956-01-01

    Woods-utilization studies were recently made on randomly selected logging operations scattered throughout Delaware. As would be expected, most of the operations studied were in pine stands in the southern part of the state. They showed that very close utilization of the trees cut was the general rule.

  15. Freshman Sexual Attitudes and Behavior.

    ERIC Educational Resources Information Center

    Nutt, Roberta L.; Sedlacek, William E.

    At the University of Maryland, 758 randomly selected incoming freshman students were administered an anonymous poll regarding their sexual attitudes and behavior. Results showed that the Maryland freshman generally resembled other U.S. college students in their sexual experience. Approximately half (52% of males, 46% of females) reported that they…

  16. Personality Dimensions, Religious Tendencies and Coping Strategies as Predictors of General Health in Iranian Mothers of Children with Intellectual Disability: A Comparison with Mothers of Typically Developing Children

    ERIC Educational Resources Information Center

    Mirsaleh, Y. R.; Rezai, H.; Khabaz, M.; Afkhami Ardekani, I.; Abdi, K.

    2011-01-01

    Background: Challenges related to rearing children with intellectual disability (ID) may cause mothers of these children to have mental health status problems. Method: A total of 124 mothers who had a child with ID and 124 mothers of typically developing children were selected using random sampling. Data were collected using General health…

  17. Effect of Expanding Medicaid for Parents on Children’s Health Insurance Coverage

    PubMed Central

    DeVoe, Jennifer E.; Marino, Miguel; Angier, Heather; O’Malley, Jean P.; Crawford, Courtney; Nelson, Christine; Tillotson, Carrie J.; Bailey, Steffani R.; Gallia, Charles; Gold, Rachel

    2016-01-01

    IMPORTANCE In the United States, health insurance is not universal. Observational studies show an association between uninsured parents and children. This association persisted even after expansions in child-only public health insurance. Oregon’s randomized Medicaid expansion for adults, known as the Oregon Experiment, created a rare opportunity to assess causality between parent and child coverage. OBJECTIVE To estimate the effect on a child’s health insurance coverage status when (1) a parent randomly gains access to health insurance and (2) a parent obtains coverage. DESIGN, SETTING, AND PARTICIPANTS Oregon Experiment randomized natural experiment assessing the results of Oregon’s 2008 Medicaid expansion. We used generalized estimating equation models to examine the longitudinal effect of a parent randomly selected to apply for Medicaid on their child’s Medicaid or Children’s Health Insurance Program (CHIP) coverage (intent-to-treat analyses). We used per-protocol analyses to understand the impact on children’s coverage when a parent was randomly selected to apply for and obtained Medicaid. Participants included 14 409 children aged 2 to 18 years whose parents participated in the Oregon Experiment. EXPOSURES For intent-to-treat analyses, the date a parent was selected to apply for Medicaid was considered the date the child was exposed to the intervention. In per-protocol analyses, exposure was defined as whether a selected parent obtained Medicaid. MAIN OUTCOMES AND MEASURES Children’s Medicaid or CHIP coverage, assessed monthly and in 6-month intervals relative to their parent’s selection date. RESULTS In the immediate period after selection, children whose parents were selected to apply significantly increased from 3830 (61.4%) to 4152 (66.6%) compared with a nonsignificant change from 5049 (61.8%) to 5044 (61.7%) for children whose parents were not selected to apply. Children whose parents were randomly selected to apply for Medicaid had 18% higher odds of being covered in the first 6 months after parent’s selection compared with children whose parents were not selected (adjusted odds ratio [AOR] = 1.18; 95% CI, 1.10–1.27). The effect remained significant during months 7 to 12 (AOR = 1.11; 95% CI, 1.03–1.19); months 13 to 18 showed a positive but not significant effect (AOR = 1.07; 95% CI, 0.99–1.14). Children whose parents were selected and obtained coverage had more than double the odds of having coverage compared with children whose parents were not selected and did not gain coverage (AOR = 2.37; 95% CI, 2.14–2.64). CONCLUSIONS AND RELEVANCE Children’s odds of having Medicaid or CHIP coverage increased when their parents were randomly selected to apply for Medicaid. Children whose parents were selected and subsequently obtained coverage benefited most. This study demonstrates a causal link between parents’ access to Medicaid coverage and their children’s coverage. PMID:25561041

  18. Inheritance in a Diallel Crossing Experiment with Longleaf Pine

    Treesearch

    E. B. Snyder; Gene Namkoong

    1978-01-01

    Seven-year-old progeny from crosses among 13 randomly selected parent trees provided genetic information on 51 growth, form, foliage, branch, bud, and pest resistance traits. Presented are he&abilities, phenotypic and genotypic variances, covariances, General Combining Ability (GCA), Specific Combining Ability (SCA), and environmental. correlations for all measured...

  19. Self-Efficacy in Incarcerated Adolescents: The Role of Family and Social Supports

    ERIC Educational Resources Information Center

    Tangeman, Keegan R.; Hall, Susan R.

    2011-01-01

    This research investigated the role of general and specific self-efficacy factors in positive family relationships and perceived social support within an U.S. incarcerated adolescent population. One hundred African American and Hispanic male adolescent participants, randomly selected from a southern California Probation Department, were included…

  20. 47 CFR 1.948 - Assignment of authorization or transfer of control, notification of consummation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... involuntary assignment or transfer. (d) Notification of consummation. In all Wireless Radio Services... radio station in the Wireless Radio Services is assigned to another party, voluntarily or involuntarily...

  1. 47 CFR 1.948 - Assignment of authorization or transfer of control, notification of consummation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... involuntary assignment or transfer. (d) Notification of consummation. In all Wireless Radio Services... radio station in the Wireless Radio Services is assigned to another party, voluntarily or involuntarily...

  2. 47 CFR 1.948 - Assignment of authorization or transfer of control, notification of consummation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... involuntary assignment or transfer. (d) Notification of consummation. In all Wireless Radio Services... radio station in the Wireless Radio Services is assigned to another party, voluntarily or involuntarily...

  3. A Design Selection Procedure.

    ERIC Educational Resources Information Center

    Kroeker, Leonard P.

    The problem of blocking on a status variable was investigated. The one-way fixed-effects analysis of variance, analysis of covariance, and generalized randomized block designs each treat the blocking problem in a different way. In order to compare these designs, it is necessary to restrict attention to experimental situations in which observations…

  4. 47 CFR 1.9010 - De facto control standard for spectrum leasing arrangements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false De facto control standard for spectrum leasing... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9010 De facto control standard for spectrum leasing arrangements. (a) Under the rules established for spectrum leasing...

  5. 47 CFR 1.9010 - De facto control standard for spectrum leasing arrangements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false De facto control standard for spectrum leasing... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9010 De facto control standard for spectrum leasing arrangements. (a) Under the rules established for spectrum leasing...

  6. 47 CFR 1.9010 - De facto control standard for spectrum leasing arrangements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false De facto control standard for spectrum leasing... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9010 De facto control standard for spectrum leasing arrangements. (a) Under the rules established for spectrum leasing...

  7. 47 CFR 1.10012 - When can I file on IBFS?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false When can I file on IBFS? 1.10012 Section 1.10012 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection International Bureau Filing System § 1.10012 When can I file on IBFS? IBFS is available...

  8. 47 CFR 1.10012 - When can I file on IBFS?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false When can I file on IBFS? 1.10012 Section 1.10012 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection International Bureau Filing System § 1.10012 When can I file on IBFS? IBFS is available...

  9. Survival in individuals with severe alpha 1-antitrypsin deficiency (PiZZ) in comparison to a general population with known smoking habits.

    PubMed

    Tanash, Hanan A; Ekström, Magnus; Rönmark, Eva; Lindberg, Anne; Piitulainen, Eeva

    2017-09-01

    Knowledge about the natural history of severe alpha 1-antitrypsin (AAT) deficiency (PiZZ) is limited. Our aim was to compare the survival of PiZZ individuals with randomly selected controls from the Swedish general population.The PiZZ subjects (n=1585) were selected from the Swedish National AATD Register. The controls (n=5999) were randomly selected from the Swedish population register. Smoking habits were known for all subjects.Median follow-up times for the PiZZ subjects (731 never-smokers) and controls (3179 never-smokers) were 12 and 17 years, respectively (p<0.001). During follow-up, 473 PiZZ subjects (30%), and 747 controls (12%) died. The PiZZ subjects had a significantly shorter survival time than the controls, p<0.001. After adjustment for gender, age, smoking habits and presence of respiratory symptoms, the risk of death was still significantly higher for the PiZZ individuals than for the controls, hazard ratio (HR) 3.2 (95% CI 2.8-3.6; p<0.001). By contrast, the risk of death was not increased in never-smoking PiZZ individuals identified by screening, compared to never-smoking controls, HR 1.2 (95% CI 0.6-2.2).The never-smoking PiZZ individuals identified by screening had a similar life expectancy to the never-smokers in the Swedish general population. Early diagnosis of AAT deficiency is of utmost importance. Copyright ©ERS 2017.

  10. Goal selection versus process control while learning to use a brain-computer interface

    NASA Astrophysics Data System (ADS)

    Royer, Audrey S.; Rose, Minn L.; He, Bin

    2011-06-01

    A brain-computer interface (BCI) can be used to accomplish a task without requiring motor output. Two major control strategies used by BCIs during task completion are process control and goal selection. In process control, the user exerts continuous control and independently executes the given task. In goal selection, the user communicates their goal to the BCI and then receives assistance executing the task. A previous study has shown that goal selection is more accurate and faster in use. An unanswered question is, which control strategy is easier to learn? This study directly compares goal selection and process control while learning to use a sensorimotor rhythm-based BCI. Twenty young healthy human subjects were randomly assigned either to a goal selection or a process control-based paradigm for eight sessions. At the end of the study, the best user from each paradigm completed two additional sessions using all paradigms randomly mixed. The results of this study were that goal selection required a shorter training period for increased speed, accuracy, and information transfer over process control. These results held for the best subjects as well as in the general subject population. The demonstrated characteristics of goal selection make it a promising option to increase the utility of BCIs intended for both disabled and able-bodied users.

  11. Pediatric Academic Productivity: Pediatric Benchmarks for the h- and g-Indices.

    PubMed

    Tschudy, Megan M; Rowe, Tashi L; Dover, George J; Cheng, Tina L

    2016-02-01

    To describe h- and g-indices benchmarks in pediatric subspecialties and general academic pediatrics. Academic productivity is measured increasingly through bibliometrics that derive a statistical enumeration of academic output and impact. The h- and g-indices incorporate the number of publications and citations. Benchmarks for pediatrics have not been reported. Thirty programs were selected randomly from pediatric residency programs accredited by the Accreditation Council for Graduate Medical Education. The h- and g-indices of department chairs were calculated. For general academic pediatrics, pediatric gastroenterology, and pediatric nephrology, a random sample of 30 programs with fellowships were selected. Within each program, an MD faculty member from each academic rank was selected randomly. Google Scholar via Harzing's Publish or Perish was used to calculate the h-index, g-index, and total manuscripts. Only peer-reviewed and English language publications were included. For Chairs, calculations from Google Scholar were compared with Scopus. For all specialties, the mean h- and g-indices significantly increased with academic rank (all P < .05) with the greatest h-indices among Chairs. The h- and g-indices were not statistically different between specialty groups of the same rank; however, mean rank h-indices had large SDs. The h-index calculation using different bibliographic databases only differed by ±1. Mean h-indices increased with academic rank and were not significantly different across the pediatric specialties. Benchmarks for h- and g-indices in pediatrics are provided and may be one measure of academic productivity and impact. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Is Knowledge Random? Introducing Sampling and Bias through Outdoor Inquiry

    ERIC Educational Resources Information Center

    Stier, Sam

    2010-01-01

    Sampling, very generally, is the process of learning about something by selecting and assessing representative parts of that population or object. In the inquiry activity described here, students learned about sampling techniques as they estimated the number of trees greater than 12 cm dbh (diameter at breast height) in a wooded, discrete area…

  13. 2005 Workforce Study: Ohio Early Childhood Centers. General Analysis

    ERIC Educational Resources Information Center

    Stoneburner, Chris

    2006-01-01

    The purpose of this study was to understand the characteristics of the current workforce in early childhood. This report highlights key characteristics of the 2005 early childhood center workforce in Ohio. Survey packets were sent to 3.600 randomly selected centers in April 2005, representing centers licensed by the Ohio Department of Job and…

  14. 47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de... any of the included services) and a spectrum lessee may enter into a short-term de facto transfer... the leased spectrum is transferred to the spectrum lessee for the duration of the spectrum leasing...

  15. 47 CFR 1.9050 - Who may sign spectrum leasing notifications and applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Who may sign spectrum leasing notifications and... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9050 Who may sign spectrum leasing notifications and applications. Under the rules set forth in this subpart, certain...

  16. 47 CFR 1.9050 - Who may sign spectrum leasing notifications and applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Who may sign spectrum leasing notifications and... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9050 Who may sign spectrum leasing notifications and applications. Under the rules set forth in this subpart, certain...

  17. 47 CFR 1.9050 - Who may sign spectrum leasing notifications and applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Who may sign spectrum leasing notifications and... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9050 Who may sign spectrum leasing notifications and applications. Under the rules set forth in this subpart, certain...

  18. 47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de... any of the included services) and a spectrum lessee may enter into a short-term de facto transfer... the leased spectrum is transferred to the spectrum lessee for the duration of the spectrum leasing...

  19. 47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PROCEDURE Grants by Random Selection Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de... any of the included services) and a spectrum lessee may enter into a short-term de facto transfer... the leased spectrum is transferred to the spectrum lessee for the duration of the spectrum leasing...

  20. Farm Women's Attitudes Toward Change in Work and Family Roles.

    ERIC Educational Resources Information Center

    Light, Harriett K.; And Others

    1983-01-01

    A study to assess attitudes of 715 respondents from 2,000 randomly selected farm women toward change in work and family roles found significant differences in women's attitudes according to age, number of children, and religious preference. Generally, attitudes regarding family roles were more conservative than were attitudes regarding career…

  1. 49 CFR 178.819 - Vibration test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vibration test. 178.819 Section 178.819... Testing of IBCs § 178.819 Vibration test. (a) General. The vibration test must be conducted for the... vibration test. (b) Test method. (1) A sample IBC, selected at random, must be filled and closed as for...

  2. Improved Neural Networks with Random Weights for Short-Term Load Forecasting

    PubMed Central

    Lang, Kun; Zhang, Mingyuan; Yuan, Yongbo

    2015-01-01

    An effective forecasting model for short-term load plays a significant role in promoting the management efficiency of an electric power system. This paper proposes a new forecasting model based on the improved neural networks with random weights (INNRW). The key is to introduce a weighting technique to the inputs of the model and use a novel neural network to forecast the daily maximum load. Eight factors are selected as the inputs. A mutual information weighting algorithm is then used to allocate different weights to the inputs. The neural networks with random weights and kernels (KNNRW) is applied to approximate the nonlinear function between the selected inputs and the daily maximum load due to the fast learning speed and good generalization performance. In the application of the daily load in Dalian, the result of the proposed INNRW is compared with several previously developed forecasting models. The simulation experiment shows that the proposed model performs the best overall in short-term load forecasting. PMID:26629825

  3. Improved Neural Networks with Random Weights for Short-Term Load Forecasting.

    PubMed

    Lang, Kun; Zhang, Mingyuan; Yuan, Yongbo

    2015-01-01

    An effective forecasting model for short-term load plays a significant role in promoting the management efficiency of an electric power system. This paper proposes a new forecasting model based on the improved neural networks with random weights (INNRW). The key is to introduce a weighting technique to the inputs of the model and use a novel neural network to forecast the daily maximum load. Eight factors are selected as the inputs. A mutual information weighting algorithm is then used to allocate different weights to the inputs. The neural networks with random weights and kernels (KNNRW) is applied to approximate the nonlinear function between the selected inputs and the daily maximum load due to the fast learning speed and good generalization performance. In the application of the daily load in Dalian, the result of the proposed INNRW is compared with several previously developed forecasting models. The simulation experiment shows that the proposed model performs the best overall in short-term load forecasting.

  4. In Darwinian evolution, feedback from natural selection leads to biased mutations.

    PubMed

    Caporale, Lynn Helena; Doyle, John

    2013-12-01

    Natural selection provides feedback through which information about the environment and its recurring challenges is captured, inherited, and accumulated within genomes in the form of variations that contribute to survival. The variation upon which natural selection acts is generally described as "random." Yet evidence has been mounting for decades, from such phenomena as mutation hotspots, horizontal gene transfer, and highly mutable repetitive sequences, that variation is far from the simplifying idealization of random processes as white (uniform in space and time and independent of the environment or context).  This paper focuses on what is known about the generation and control of mutational variation, emphasizing that it is not uniform across the genome or in time, not unstructured with respect to survival, and is neither memoryless nor independent of the (also far from white) environment. We suggest that, as opposed to frequentist methods, Bayesian analysis could capture the evolution of nonuniform probabilities of distinct classes of mutation, and argue not only that the locations, styles, and timing of real mutations are not correctly modeled as generated by a white noise random process, but that such a process would be inconsistent with evolutionary theory. © 2013 New York Academy of Sciences.

  5. Prevalence of latent tuberculous infection among adults in the general population of Ca Mau, Viet Nam.

    PubMed

    Marks, G B; Nhung, N V; Nguyen, T A; Hoa, N B; Khoa, T H; Son, N V; Phuong, N T B; Tin, D M; Ho, J; Fox, G J

    2018-03-01

    The study was conducted in a randomly selected sample of persons aged 15 years living in Ca Mau Province, southern Viet Nam. To estimate the prevalence of latent tuberculous infection (LTBI) in the general adult population of this province of Viet Nam. The secondary objective was to examine age and sex differences in prevalence. A cross-sectional survey was conducted in a cluster-random sample of the population. Clusters were subcommunes. The presence of LTBI was assessed using the QuantiFERON®-TB Gold In-Tube test system. QuantiFERON tests were performed among 1319 persons aged 15 years (77.7% of those selected). The overall prevalence of positive tests was 36.8% (95%CI 33.4-40.3). The prevalence of a positive test was lower in females than in males (31.0% vs. 44.7%, OR 0.57, 95%CI 0.45-0.72, P < 0.0001). The prevalence of positive tests increased with increasing age quintile (P < 0.0001). More than one third of the general adult population in a province in southern Viet Nam have evidence of LTBI. Although LTBI prevalence is higher in males, the sex difference is not as great as that for TB notification rates.

  6. Perceptions and utilization of primary health care services in Iraq: findings from a national household survey

    PubMed Central

    2011-01-01

    Background After many years of sanctions and conflict, Iraq is rebuilding its health system, with a strong emphasis on the traditional hospital-based services. A network exists of public sector hospitals and clinics, as well as private clinics and a few private hospitals. Little data are available about the approximately 1400 Primary Health Care clinics (PHCCs) staffed with doctors. How do Iraqis utilize primary health care services? What are their preferences and perceptions of public primary health care clinics and private primary care services in general? How does household wealth affect choice of services? Methods A 1256 household national survey was conducted in the catchment areas of randomly selected PHCCs in Iraq. A cluster of 10 households, beginning with a randomly selected start household, were interviewed in the service areas of seven public sector PHCC facilities in each of 17 of Iraq's 18 governorates. A questionnaire was developed using key informants. Teams of interviewers, including both males and females, were recruited and provided a week of training which included field practice. Teams then gathered data from households in the service areas of randomly selected clinics. Results Iraqi participants are generally satisfied with the quality of primary care services available both in the public and private sector. Private clinics are generally the most popular source of primary care, however the PHCCs are utilized more by poorer households. In spite of free services available at PHCCs many households expressed difficulty in affording health care, especially in the purchase of medications. There is no evidence of informal payments to secure health services in the public sector. Conclusions There is widespread satisfaction reported with primary health care services, and levels did not differ appreciably between public and private sectors. The public sector PHCCs are preferentially used by poorer populations where they are important providers. PHCC services are indeed free, with little evidence of informal payments to providers. PMID:22176866

  7. For the general internist: a review of relevant 2013 innovations in medical education.

    PubMed

    Roy, Brita; Willett, Lisa L; Bates, Carol; Duffy, Briar; Dunn, Kathel; Karani, Reena; Chheda, Shobhina G

    2015-04-01

    We conducted a review of articles published in 2013 to identify high-quality research in medical education that was relevant to general medicine education practice. Our review team consisted of six general internists with expertise in medical education of varying ranks, as well as a professional medical librarian. We manually searched 15 journals in pairs, and performed an online search using the PubMed search engine for all original research articles in medical education published in 2013. From the total 4,181 citations identified, we selected 65 articles considered most relevant to general medicine educational practice. Each team member then independently reviewed and rated the quality of each selected article using the modified Medical Education Research Study Quality Instrument. We then reviewed the quality and relevance of each selected study and grouped them into categories of propensity for inclusion. Nineteen studies were felt to be of adequate quality and were of moderate to high propensity for inclusion. Team members then independently voted for studies they felt to be of the highest relevance and quality within the 19 selected studies. The ten articles with the greatest number of votes were included in the review. We categorized the studies into five general themes: Improving Clinical Skills in UME, Inpatient Clinical Teaching Methods, Advancements in Continuity Clinic, Handoffs/Transitions in Care, and Trainee Assessment. Most studies in our review of the 2013 literature in general medical education were limited to single institutions and non-randomized study designs; we identified significant limitations of each study. Selected articles may inform future research and practice of medical educators.

  8. Greedy Gossip With Eavesdropping

    NASA Astrophysics Data System (ADS)

    Ustebay, Deniz; Oreshkin, Boris N.; Coates, Mark J.; Rabbat, Michael G.

    2010-07-01

    This paper presents greedy gossip with eavesdropping (GGE), a novel randomized gossip algorithm for distributed computation of the average consensus problem. In gossip algorithms, nodes in the network randomly communicate with their neighbors and exchange information iteratively. The algorithms are simple and decentralized, making them attractive for wireless network applications. In general, gossip algorithms are robust to unreliable wireless conditions and time varying network topologies. In this paper we introduce GGE and demonstrate that greedy updates lead to rapid convergence. We do not require nodes to have any location information. Instead, greedy updates are made possible by exploiting the broadcast nature of wireless communications. During the operation of GGE, when a node decides to gossip, instead of choosing one of its neighbors at random, it makes a greedy selection, choosing the node which has the value most different from its own. In order to make this selection, nodes need to know their neighbors' values. Therefore, we assume that all transmissions are wireless broadcasts and nodes keep track of their neighbors' values by eavesdropping on their communications. We show that the convergence of GGE is guaranteed for connected network topologies. We also study the rates of convergence and illustrate, through theoretical bounds and numerical simulations, that GGE consistently outperforms randomized gossip and performs comparably to geographic gossip on moderate-sized random geometric graph topologies.

  9. Biological Principles and Threshold Concepts for Understanding Natural Selection. Implications for Developing Visualizations as a Pedagogic Tool

    NASA Astrophysics Data System (ADS)

    Tibell, Lena A. E.; Harms, Ute

    2017-11-01

    Modern evolutionary theory is both a central theory and an integrative framework of the life sciences. This is reflected in the common references to evolution in modern science education curricula and contexts. In fact, evolution is a core idea that is supposed to support biology learning by facilitating the organization of relevant knowledge. In addition, evolution can function as a pivotal link between concepts and highlight similarities in the complexity of biological concepts. However, empirical studies in many countries have for decades identified deficiencies in students' scientific understanding of evolution mainly focusing on natural selection. Clearly, there are major obstacles to learning natural selection, and we argue that to overcome them, it is essential to address explicitly the general abstract concepts that underlie the biological processes, e.g., randomness or probability. Hence, we propose a two-dimensional framework for analyzing and structuring teaching of natural selection. The first—purely biological—dimension embraces the three main principles variation, heredity, and selection structured in nine key concepts that form the core idea of natural selection. The second dimension encompasses four so-called thresholds, i.e., general abstract and/or non-perceptual concepts: randomness, probability, spatial scales, and temporal scales. We claim that both of these dimensions must be continuously considered, in tandem, when teaching evolution in order to allow development of a meaningful understanding of the process. Further, we suggest that making the thresholds tangible with the aid of appropriate kinds of visualizations will facilitate grasping of the threshold concepts, and thus, help learners to overcome the difficulties in understanding the central theory of life.

  10. Coevolutionary dynamics in large, but finite populations

    NASA Astrophysics Data System (ADS)

    Traulsen, Arne; Claussen, Jens Christian; Hauert, Christoph

    2006-07-01

    Coevolving and competing species or game-theoretic strategies exhibit rich and complex dynamics for which a general theoretical framework based on finite populations is still lacking. Recently, an explicit mean-field description in the form of a Fokker-Planck equation was derived for frequency-dependent selection with two strategies in finite populations based on microscopic processes [A. Traulsen, J. C. Claussen, and C. Hauert, Phys. Rev. Lett. 95, 238701 (2005)]. Here we generalize this approach in a twofold way: First, we extend the framework to an arbitrary number of strategies and second, we allow for mutations in the evolutionary process. The deterministic limit of infinite population size of the frequency-dependent Moran process yields the adjusted replicator-mutator equation, which describes the combined effect of selection and mutation. For finite populations, we provide an extension taking random drift into account. In the limit of neutral selection, i.e., whenever the process is determined by random drift and mutations, the stationary strategy distribution is derived. This distribution forms the background for the coevolutionary process. In particular, a critical mutation rate uc is obtained separating two scenarios: above uc the population predominantly consists of a mixture of strategies whereas below uc the population tends to be in homogeneous states. For one of the fundamental problems in evolutionary biology, the evolution of cooperation under Darwinian selection, we demonstrate that the analytical framework provides excellent approximations to individual based simulations even for rather small population sizes. This approach complements simulation results and provides a deeper, systematic understanding of coevolutionary dynamics.

  11. ADULT EDUCATION IN FAMILY BUSINESS PRACTICES.

    ERIC Educational Resources Information Center

    DRAPER, ARGEN H.

    IN A STUDY OF FAMILY MONEY MANAGEMENT, A QUESTIONNAIRE WAS COMPLETED BY WIVES IN 94 FAMILIES SELECTED AT RANDOM FROM THOSE WHO HAD USED THE SERVICES OF THE EXTENSION OFFICE IN DEAF SMITH COUNTY, TEXAS. ONLY ONE FAMILY IN THE STUDY FOLLOWED ALL OF THE 16 SPECIFIED BUSINESS PRACTICES. IT WAS FOUND THAT, IN GENERAL, FAMILIES WERE FOLLOWING SPECIFIED…

  12. A Follow-Up of Subjects Scoring above 180 IQ in Terman's "Genetic Studies of Genius."

    ERIC Educational Resources Information Center

    Feldman, David Henry

    1984-01-01

    Using the Terman files, 26 subjects with scores above 180 IQ were compared with 26 randomly selected subjects from Terman's sample. Findings were generally that the extra IQ points made little difference and that extremely high IQ does not seem to indicate "genius" in the commonly understood sense. (Author/CL)

  13. 47 CFR 1.991 - Contents of petitions for declaratory ruling under the Communications Act of 1934.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... assignment or transfer of control, specify for each named applicant: (i) The File No(s). of the associated... consist of the following rights: (i) The power to prevent the sale or pledge of all or substantially all...

  14. 47 CFR 1.991 - Contents of petitions for declaratory ruling under the Communications Act of 1934.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... COMMISSION GENERAL PRACTICE AND PROCEDURE Grants by Random Selection Wireless Radio Services Applications and... assignment or transfer of control, specify for each named applicant: (i) The File No(s). of the associated... consist of the following rights: (i) The power to prevent the sale or pledge of all or substantially all...

  15. FACILITIES AND EQUIPMENT AVAILABLE FOR TEACHING SCIENCE IN PUBLIC HIGH SCHOOLS, 1958-59.

    ERIC Educational Resources Information Center

    KOELSCHE, CHARLES L.; SOLBERG, ARCHIE N.

    SURVEYS WERE CONDUCTED TO DETERMINE THE AVAILABILITY OF HIGH SCHOOL SCIENCE FACILITIES AND EQUIPMENT IN SEVEN STATES. THIS WAS ACCOMPLISHED THROUGH PERSONAL INSPECTIONS BY A PROJECT COMMITTEE, USING CHECKLISTS OF APPROXIMATELY 850 SCHOOLS SELECTED AT RANDOM. AN ANALYSIS OF THE DATA WAS THEN MADE, AND SOME GENERAL IMPLICATIONS WERE SUGGESTED.…

  16. Effects of Self-Efficacy on Social Entrepreneurship in Education: A Correlational Research

    ERIC Educational Resources Information Center

    Konakll, Tugba

    2015-01-01

    The aim of this research is to determine the effects of pre-service teachers' self-efficacy on their social entrepreneurship characteristics. The population of this study consisted of 220 randomly selected pre-service teachers in Kocaeli University Faculty of Education in Turkey. General Self Efficacy Scale-Turkish Form and Pre-service Teachers'…

  17. The Experience of Burnout in Counselor Education: Considering Perceived Worklife Fit and Turnover Intention

    ERIC Educational Resources Information Center

    Coaston, Susannah C.

    2013-01-01

    The purpose of this study was to explore experience of burnout in Counselor Education faculty. A national sample of Counselor Educators were randomly selected to participate anonymously in the online study. Participants completed the Maslach Burnout Inventory-General Survey (MBI-GS) which measures the three dimensions of burnout: exhaustion,…

  18. Factual knowledge about AIDS and dating practices among high school students from selected schools.

    PubMed

    Nyachuru-Sihlangu, R H; Ndlovu, J

    1992-06-01

    Following various educational strategies by governmental and non-governmental organisations to educate youths and school teachers about HIV infection and prevention, this KABP survey was one attempt to evaluate the results. The study sample of 478 high school students was drawn from four randomly selected schools in Mashonaland and Matabeleland including high and low density, government and mission co-educational schools. The sample was randomly selected and stratified to represent sex and grade level. The KABP self administered questionnaire was used. The paper analyses the relationship between the knowledge and dating patterns. Generally, respondents demonstrated a 50pc to 80pc accuracy of factual knowledge. Of the 66pc Forms I through IV pupils who dated, 30pc preferred only sexually involved relationships and a small number considered the possibility of HIV/AIDS infection. A theoretically based tripartite coalition involving the school, the family health care services for education, guidance and support to promote responsible behaviour throughout childhood was suggested.

  19. Uncertain programming models for portfolio selection with uncertain returns

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Peng, Jin; Li, Shengguo

    2015-10-01

    In an indeterminacy economic environment, experts' knowledge about the returns of securities consists of much uncertainty instead of randomness. This paper discusses portfolio selection problem in uncertain environment in which security returns cannot be well reflected by historical data, but can be evaluated by the experts. In the paper, returns of securities are assumed to be given by uncertain variables. According to various decision criteria, the portfolio selection problem in uncertain environment is formulated as expected-variance-chance model and chance-expected-variance model by using the uncertainty programming. Within the framework of uncertainty theory, for the convenience of solving the models, some crisp equivalents are discussed under different conditions. In addition, a hybrid intelligent algorithm is designed in the paper to provide a general method for solving the new models in general cases. At last, two numerical examples are provided to show the performance and applications of the models and algorithm.

  20. Do early changes in the HAM-D-17 anxiety/somatization factor items affect the treatment outcome among depressed outpatients? Comparison of two controlled trials of St John's wort (Hypericum perforatum) versus a SSRI.

    PubMed

    Bitran, Stella; Farabaugh, Amy H; Ameral, Victoria E; LaRocca, Rachel A; Clain, Alisabet J; Fava, Maurizio; Mischoulon, David

    2011-07-01

    To assess whether early changes in Hamilton Depression Rating Scale-17 anxiety/somatization items predict remission in two controlled studies of Hypericum perforatum (St John's wort) versus selective serotonin reuptake inhibitors for major depressive disorder. The Hypericum Depression Trial Study Group (National Institute of Mental Health) randomized 340 patients to Hypericum, sertraline, or placebo for 8 weeks, whereas the Massachusetts General Hospital study randomized 135 patients to Hypericum, fluoxetine, or placebo for 12 weeks. The investigators examined whether remission was associated with early changes in anxiety/somatization symptoms. In the National Institute of Mental Health study, significant associations were observed between remission and early improvement in the anxiety (psychic) item (sertraline arm), somatic (gastrointestinal item; Hypericum arm), and somatic (general) symptoms (placebo arm). None of the three treatment arms of the Massachusetts General Hospital study showed significant associations between anxiety/somatization symptoms and remission. When both study samples were pooled, we found associations for anxiety (psychic; selective serotonin reuptake inhibitors arm), somatic (gastrointestinal), and hypochondriasis (Hypericum arm), and anxiety (psychic) and somatic (general) symptoms (placebo arm). In the entire sample, remission was associated with the improvement in the anxiety (psychic), somatic (gastrointestinal), and somatic (general) items. The number and the type of anxiety/somatization items associated with remission varied depending on the intervention. Early scrutiny of the Hamilton Depression Rating Scale-17 anxiety/somatization items may help to predict remission of major depressive disorder.

  1. Programmable disorder in random DNA tilings

    NASA Astrophysics Data System (ADS)

    Tikhomirov, Grigory; Petersen, Philip; Qian, Lulu

    2017-03-01

    Scaling up the complexity and diversity of synthetic molecular structures will require strategies that exploit the inherent stochasticity of molecular systems in a controlled fashion. Here we demonstrate a framework for programming random DNA tilings and show how to control the properties of global patterns through simple, local rules. We constructed three general forms of planar network—random loops, mazes and trees—on the surface of self-assembled DNA origami arrays on the micrometre scale with nanometre resolution. Using simple molecular building blocks and robust experimental conditions, we demonstrate control of a wide range of properties of the random networks, including the branching rules, the growth directions, the proximity between adjacent networks and the size distribution. Much as combinatorial approaches for generating random one-dimensional chains of polymers have been used to revolutionize chemical synthesis and the selection of functional nucleic acids, our strategy extends these principles to random two-dimensional networks of molecules and creates new opportunities for fabricating more complex molecular devices that are organized by DNA nanostructures.

  2. Evolution of female multiple mating: A quantitative model of the “sexually selected sperm” hypothesis

    PubMed Central

    Bocedi, Greta; Reid, Jane M

    2015-01-01

    Explaining the evolution and maintenance of polyandry remains a key challenge in evolutionary ecology. One appealing explanation is the sexually selected sperm (SSS) hypothesis, which proposes that polyandry evolves due to indirect selection stemming from positive genetic covariance with male fertilization efficiency, and hence with a male's success in postcopulatory competition for paternity. However, the SSS hypothesis relies on verbal analogy with “sexy-son” models explaining coevolution of female preferences for male displays, and explicit models that validate the basic SSS principle are surprisingly lacking. We developed analogous genetically explicit individual-based models describing the SSS and “sexy-son” processes. We show that the analogy between the two is only partly valid, such that the genetic correlation arising between polyandry and fertilization efficiency is generally smaller than that arising between preference and display, resulting in less reliable coevolution. Importantly, indirect selection was too weak to cause polyandry to evolve in the presence of negative direct selection. Negatively biased mutations on fertilization efficiency did not generally rescue runaway evolution of polyandry unless realized fertilization was highly skewed toward a single male, and coevolution was even weaker given random mating order effects on fertilization. Our models suggest that the SSS process is, on its own, unlikely to generally explain the evolution of polyandry. PMID:25330405

  3. Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

    PubMed

    Borak, T B

    1986-04-01

    Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

  4. Public perspectives on nuclear security. US national security surveys, 1993--1997

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Herron, K.G.; Jenkins-Smith, H.C.

    This is the third report in a series of studies to examine how US attitudes about nuclear security are evolving in the post-Cold War era and to identify trends in public perceptions and preferences relevant to the evolution of US nuclear security policy. It presents findings from three surveys: a nationwide telephone survey of randomly selected members of the US general public; a written survey of randomly selected members of American Men and Women of Science; and a written survey of randomly selected state legislators from all fifty US states. Key areas of investigation included nuclear security, cooperation between USmore » and Russian scientists about nuclear issues, vulnerabilities of critical US infrastructures and responsibilities for their protection, and broad areas of US national science policy. While international and US national security were seen to be slowly improving, the primary nuclear threat to the US was perceived to have shifted from Russia to China. Support was found for nuclear arms control measures, including mutual reductions in stockpiles. However, respondents were pessimistic about eliminating nuclear armaments, and nuclear deterrence continued to be highly values. Participants favored decreasing funding f/or developing and testing new nuclear weapons, but supported increased investments in nuclear weapons infrastructure. Strong concerns were expressed about nuclear proliferation and the potential for nuclear terrorism. Support was evident for US scientific cooperation with Russia to strengthen security of Russian nuclear assets. Elite and general public perceptions of external and domestic nuclear weapons risks and external and domestic nuclear weapons benefits were statistically significantly related to nuclear weapons policy options and investment preferences. Demographic variables and individual belief systems were systematically related both to risk and benefit perceptions and to policy and spending preferences.« less

  5. Effect of anger management education on mental health and aggression of prisoner women.

    PubMed

    Bahrami, Elaheh; Mazaheri, Maryam Amidi; Hasanzadeh, Akbar

    2016-01-01

    "Uncontrolled anger" threats the compatible and health of people as serious risk. The effects of weaknesses and shortcomings in the management of anger, from personal distress and destruction interpersonal relationships beyond and linked to the public health problems, lack of compromises, and aggressive behavior adverse outcomes. This study investigates the effects of anger management education on mental health and aggression of prisoner women in Isfahan. The single-group quasi-experimental (pretest, posttest) by prisoner women in the central prison of Isfahan was done. Multi-stage random sampling method was used. Initially, 165 women were selected randomly and completed the Buss and Perry Aggression Questionnaire and the General Health Questionnaire-28, and among these, those with scores >78 (the cut point) in aggression scale was selected and among them 70 were randomly selected. In the next step, interventions in four 90 min training sessions were conducted. Posttest was performed within 1-month after the intervention. Data were analyzed using SPSS-20 software. Data analysis showed that anger management training was effective in reducing aggression (P < 0.001) and also had a positive effect on mental health (P < 0.001). According to the importance of aggression in consistency and individual and collective health and according to findings, presented educational programs on anger management is essential for female prisoners.

  6. From Politicized Adult Education to Market Oriented Adult Higher Education: How Adult Education Practice in One Region is Different from Another

    ERIC Educational Resources Information Center

    Wang, Victor C. X.; Mott, Vivian W.

    2010-01-01

    This study investigated the general instructional modes of adult educators in Southeast China and Northeast China. The study utilized Conti's (1983, 2004) Principles of Adult Learning Scale (PALS) to measure instructional modes of adult educators. Data were collected from 112 randomly selected participants engaged in teaching Chinese adult…

  7. Dentists' Preferences for Diagnosis, Management and Referral of Chronic Oro-Facial Pain: Results from a National Survey

    ERIC Educational Resources Information Center

    Aggarwal, Vishal R.; Joughin, Amy; Zakrzewska, Joanna; Appelbe, Priscilla; Tickle, Martin

    2012-01-01

    Aim: To explore the diagnosis, treatment and referral patterns of chronic oro-facial pain patients by generalist primary care dentists (GDPs) in the UK. Methods: A cross-sectional survey was conducted using a non-stratified random sample of 500 GDPs who were selected from the General Dental Council register. A self-complete postal questionnaire…

  8. Social Involvement of Children with Autism Spectrum Disorders in Elementary School Classrooms

    ERIC Educational Resources Information Center

    Rotheram-Fuller, Erin; Kasari, Connie; Chamberlain, Brandt; Locke, Jill

    2010-01-01

    Background: Children with autism spectrum disorders (ASD) are increasingly included in general education classrooms in an effort to improve their social involvement. Methods: Seventy-nine children with ASD and 79 randomly selected, gender-matched peers (88.6% male) in 75 early (K-1), middle (2nd-3rd), and late (4th-5th) elementary classrooms…

  9. Linkage analysis of systolic blood pressure: a score statistic and computer implementation

    PubMed Central

    Wang, Kai; Peng, Yingwei

    2003-01-01

    A genome-wide linkage analysis was conducted on systolic blood pressure using a score statistic. The randomly selected Replicate 34 of the simulated data was used. The score statistic was applied to the sibships derived from the general pedigrees. An add-on R program to GENEHUNTER was developed for this analysis and is freely available. PMID:14975145

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

    Treesearch

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

    2009-01-01

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

  11. The Effects of Computer Animated Dissection versus Preserved Animal Dissection on the Student Achievement in a High School Biology Class.

    ERIC Educational Resources Information Center

    Kariuki, Patrick; Paulson, Ronda

    The purpose of this study was to examine the effectiveness of computer-animated dissection techniques versus the effectiveness of traditional dissection techniques as related to student achievement. The sample used was 104 general biology students from a small, rural high school in Northeast Tennessee. Random selection was used to separate the…

  12. Benchmarking protein classification algorithms via supervised cross-validation.

    PubMed

    Kertész-Farkas, Attila; Dhir, Somdutta; Sonego, Paolo; Pacurar, Mircea; Netoteia, Sergiu; Nijveen, Harm; Kuzniar, Arnold; Leunissen, Jack A M; Kocsor, András; Pongor, Sándor

    2008-04-24

    Development and testing of protein classification algorithms are hampered by the fact that the protein universe is characterized by groups vastly different in the number of members, in average protein size, similarity within group, etc. Datasets based on traditional cross-validation (k-fold, leave-one-out, etc.) may not give reliable estimates on how an algorithm will generalize to novel, distantly related subtypes of the known protein classes. Supervised cross-validation, i.e., selection of test and train sets according to the known subtypes within a database has been successfully used earlier in conjunction with the SCOP database. Our goal was to extend this principle to other databases and to design standardized benchmark datasets for protein classification. Hierarchical classification trees of protein categories provide a simple and general framework for designing supervised cross-validation strategies for protein classification. Benchmark datasets can be designed at various levels of the concept hierarchy using a simple graph-theoretic distance. A combination of supervised and random sampling was selected to construct reduced size model datasets, suitable for algorithm comparison. Over 3000 new classification tasks were added to our recently established protein classification benchmark collection that currently includes protein sequence (including protein domains and entire proteins), protein structure and reading frame DNA sequence data. We carried out an extensive evaluation based on various machine-learning algorithms such as nearest neighbor, support vector machines, artificial neural networks, random forests and logistic regression, used in conjunction with comparison algorithms, BLAST, Smith-Waterman, Needleman-Wunsch, as well as 3D comparison methods DALI and PRIDE. The resulting datasets provide lower, and in our opinion more realistic estimates of the classifier performance than do random cross-validation schemes. A combination of supervised and random sampling was used to construct model datasets, suitable for algorithm comparison.

  13. Evaluation of family intervention through unobtrusive audio recordings: experiences in "bugging" children.

    PubMed

    Johnson, S M; Christensen, A; Bellamy, G T

    1976-01-01

    Five children referred to a child-family intervention program wore a radio transmitter in the home during pre-intervention and termination assessments. The transmitter broadcast to a receiver-recording apparatus in the home (either activated by an interval timer at predetermined "random" times or by parents at predetermined "picked" times). "Picked" times were parent-selected situations during which problems typically occurred (e.g., bedtime). Parents activated the recorder regularly whether or not problems occurred. Child-deviant, parent-negative, and parent-commanding behaviors were significantly higher at the picked times during pretest than at random times. At posttest, behaviors in all three classes were substantially reduced at picked times, but not at random times. For individual subject data, reductions occurred in at least two of the three dependent variables for three of the five cases during random time assessments. In general, the behavioral outcome data corresponded to parent-attitude reports and parent-collected observation data.

  14. The effect of asthma education program on knowledge of school teachers: a randomized controlled trial.

    PubMed

    Kawafha, Mariam M; Tawalbeh, Loai Issa

    2015-04-01

    The purpose of this study was to examine the effect of an asthma education program on schoolteachers' knowledge. Pre-test-post-test experimental randomized controlled design was used. A multistage-cluster sampling technique was used to randomly select governorate, primary schools, and schoolteachers. Schoolteachers were randomly assigned either to the experimental group (n = 36) and attended three educational sessions or to the control group (n = 38) who did not receive any intervention. Knowledge about asthma was measured using the Asthma General Knowledge Questionnaire for Adults (AGKQA). The results indicated that teachers in the experimental group showed significantly (p < .001) higher knowledge of asthma in the first post-test and the second post-test compared with those in the control group. Implementing asthma education enhanced schoolteachers' knowledge of asthma. The asthma education program should target schoolteachers to improve knowledge about asthma. © The Author(s) 2014.

  15. Public perceptions of key performance indicators of healthcare in Alberta, Canada.

    PubMed

    Northcott, Herbert C; Harvey, Michael D

    2012-06-01

    To examine the relationship between public perceptions of key performance indicators assessing various aspects of the health-care system. Cross-sequential survey research. Annual telephone surveys of random samples of adult Albertans selected by random digit dialing and stratified according to age, sex and region (n = 4000 for each survey year). The survey questionnaires included single-item measures of key performance indicators to assess public perceptions of availability, accessibility, quality, outcome and satisfaction with healthcare. Cronbach's α and factor analysis were used to assess the relationship between key performance indicators focusing on the health-care system overall and on a recent interaction with the health-care system. The province of Alberta, Canada during the years 1996-2004. Four thousand adults randomly selected each survey year. Survey questions measuring public perceptions of healthcare availability, accessibility, quality, outcome and satisfaction with healthcare. Factor analysis identified two principal components with key performance indicators focusing on the health system overall loading most strongly on the first component and key performance indicators focusing on the most recent health-care encounter loading most strongly on the second component. Assessments of the quality of care most recently received, accessibility of that care and perceived outcome of care tended to be higher than the more general assessments of overall health system quality and accessibility. Assessments of specific health-care encounters and more general assessments of the overall health-care system, while related, nevertheless comprise separate dimensions for health-care evaluation.

  16. Random forests ensemble classifier trained with data resampling strategy to improve cardiac arrhythmia diagnosis.

    PubMed

    Ozçift, Akin

    2011-05-01

    Supervised classification algorithms are commonly used in the designing of computer-aided diagnosis systems. In this study, we present a resampling strategy based Random Forests (RF) ensemble classifier to improve diagnosis of cardiac arrhythmia. Random forests is an ensemble classifier that consists of many decision trees and outputs the class that is the mode of the class's output by individual trees. In this way, an RF ensemble classifier performs better than a single tree from classification performance point of view. In general, multiclass datasets having unbalanced distribution of sample sizes are difficult to analyze in terms of class discrimination. Cardiac arrhythmia is such a dataset that has multiple classes with small sample sizes and it is therefore adequate to test our resampling based training strategy. The dataset contains 452 samples in fourteen types of arrhythmias and eleven of these classes have sample sizes less than 15. Our diagnosis strategy consists of two parts: (i) a correlation based feature selection algorithm is used to select relevant features from cardiac arrhythmia dataset. (ii) RF machine learning algorithm is used to evaluate the performance of selected features with and without simple random sampling to evaluate the efficiency of proposed training strategy. The resultant accuracy of the classifier is found to be 90.0% and this is a quite high diagnosis performance for cardiac arrhythmia. Furthermore, three case studies, i.e., thyroid, cardiotocography and audiology, are used to benchmark the effectiveness of the proposed method. The results of experiments demonstrated the efficiency of random sampling strategy in training RF ensemble classification algorithm. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Random mutagenesis of the hyperthermophilic archaeon Pyrococcus furiosus using in vitro mariner transposition and natural transformation.

    PubMed

    Guschinskaya, Natalia; Brunel, Romain; Tourte, Maxime; Lipscomb, Gina L; Adams, Michael W W; Oger, Philippe; Charpentier, Xavier

    2016-11-08

    Transposition mutagenesis is a powerful tool to identify the function of genes, reveal essential genes and generally to unravel the genetic basis of living organisms. However, transposon-mediated mutagenesis has only been successfully applied to a limited number of archaeal species and has never been reported in Thermococcales. Here, we report random insertion mutagenesis in the hyperthermophilic archaeon Pyrococcus furiosus. The strategy takes advantage of the natural transformability of derivatives of the P. furiosus COM1 strain and of in vitro Mariner-based transposition. A transposon bearing a genetic marker is randomly transposed in vitro in genomic DNA that is then used for natural transformation of P. furiosus. A small-scale transposition reaction routinely generates several hundred and up to two thousands transformants. Southern analysis and sequencing showed that the obtained mutants contain a single and random genomic insertion. Polyploidy has been reported in Thermococcales and P. furiosus is suspected of being polyploid. Yet, about half of the mutants obtained on the first selection are homozygous for the transposon insertion. Two rounds of isolation on selective medium were sufficient to obtain gene conversion in initially heterozygous mutants. This transposition mutagenesis strategy will greatly facilitate functional exploration of the Thermococcales genomes.

  18. Thromboembolism prevention in surgery of digestive cancer.

    PubMed

    Malafaia, Osvaldo; Montagnini, Andre Luís; Luchese, Angélica; Accetta, Antonio Carlos; Zilberstein, Bruno; Malheiros, Carlos Alberto; Jacob, Carlos Eduardo; Quireze-Junior, Claudemiro; Bresciani, Cláudio José Caldas; Kruel, Cleber Dario Pinto; Cecconello, Ivan; Sad, Eduardo Fonseca; Ohana, Jorge Alberto Langbeck; Aguilar-Nascimento, José Eduardo de; Manso, José Eduardo Ferreira; Ribas-Filho, Jurandir Marcondes; Santo, Marco Aurélio; Andreollo, Nelson Adami; Torres, Orlando Jorge Martins; Herman, Paulo; Cuenca, Ronaldo Mafia; Sallum, Rubens Antônio Aissar; Bernardo, Wanderley Marques

    2012-01-01

    The venous thromboembolism is a common complication after surgical treatment in general and, in particular, on the therapeutic management on cancer. Surgery of the digestive tract has been reported to induce this complication. Patients with digestive cancer have substantial increased risk of initial or recurrent thromboembolism. To provide to surgeons working in digestive surgery and general surgery guidance on how to make safe thromboprophylaxis for patients requiring operations in the treatment of their gastrointestinal malignancies. The guideline was based on 15 relevant clinical issues and related to the risk factors, treatment and prognosis of the patient undergoing surgical treatment of cancer on digestive tract. They focused thromboembolic events associated with operations and thromboprophylaxis. The questions were structured using the PICO (Patient, Intervention or Indicator, Comparison and Outcome), allowing strategies to generate evidence on the main primary bases of scientific information (Medline / Pubmed, Embase, Lilacs / Scielo, Cochrane Library, PreMedline via OVID). Evidence manual search was also conducted (BDTD and IBICT). The evidence was recovered from the selected critical evaluation using discriminatory instruments (scores) according to the category of the question: risk, prognosis and therapy (JADAD Randomized Clinical Trials and New Castle Ottawa Scale for studies not randomized). After defining potential studies to support the recommendations, they were selected by the strength of evidence and grade of recommendation according to the classification of Oxford, including the available evidence of greater strength. A total of 53,555 papers by title and / or abstract related to issue were found. Of this total were selected (1st selection) 478 studies that were evaluated as full-text. From them to support the recommendations were included in the consensus 132 papers. The 15 questions could be answered with evidence grade of articles with 31 A, 130 B, 1 C and 0 D. It was possible to prepare safe recommendations as guidance for thromboembolism prophylaxis in operations on the digestive tract malignancies, addressing the most frequent topics of everyday work of digestive and general surgeons.

  19. Creating Message Strategies for an AIDS Campaign: A Survey of the Basis of Student Awareness.

    ERIC Educational Resources Information Center

    Brislin, Tom; Miyamoto, Craig T.

    A study assessed the general knowledge of AIDS and its prevention among college students, and determined the source of that knowledge. A class of 17 senior-level journalism students used a focus group approach to select the most useful questions about AIDS and its prevention. The survey was administered by telephone to a random sample of 372…

  20. Job Training Partnership Act: Participants, Services, and Outcomes. Statement before the Committee on Education and Labor, United States House of Representatives.

    ERIC Educational Resources Information Center

    Thompson, Lawrence H.

    The U.S. General Accounting Office studied the characteristics of individual participants in training provided by the Job Training Partnership Act (JTPA), the kinds and intensity of services they received, and the occupations in which they were employed after leaving the program. Visits to 63 randomly selected service delivery areas provided…

  1. Determining the factors associated with seedling herbivory on afforested carbon sequestration sites in the Lower Mississippi Alluvial Valley: preliminary results

    Treesearch

    Daniel C. Sumerall; Donald L. Grebner; Jeanne C. Jones; Stephen C. Grado; Richard P. Maiers; Keith L. Belli

    2010-01-01

    One causal factor of failed afforestation attempts in the Lower Mississippi Alluvial Valley (LMAV) is mammalian herbivory. Herbivory of seedlings generally reduces growth and can also lead to seedling mortality. Seedlings were randomly selected for monitoring throughout the first growing season. Growth and survival data were recorded, as were signs of mammalian...

  2. Gender, Alcohol Consumption Patterns, and Engagement in Sexually Intimate Behaviors among Adolescents and Young Adults in Nha Trang, Viet Nam

    ERIC Educational Resources Information Center

    Kaljee, Linda M.; Green, Mackenzie S.; Zhan, Min; Riel, Rosemary; Lerdboon, Porntip; Lostutter, Ty W.; Tho, Le Huu; Luong, Vo Van; Minh, Truong Tan

    2011-01-01

    A randomly selected cross-sectional survey was conducted with 880 youth (16 to 24 years) in Nha Trang City to assess relationships between alcohol consumption and sexual behaviors. A timeline followback method was employed. Chi-square, generalized logit modeling and logistic regression analyses were performed. Of the sample, 78.2% male and 56.1%…

  3. Efficient one-cycle affinity selection of binding proteins or peptides specific for a small-molecule using a T7 phage display pool.

    PubMed

    Takakusagi, Yoichi; Kuramochi, Kouji; Takagi, Manami; Kusayanagi, Tomoe; Manita, Daisuke; Ozawa, Hiroko; Iwakiri, Kanako; Takakusagi, Kaori; Miyano, Yuka; Nakazaki, Atsuo; Kobayashi, Susumu; Sugawara, Fumio; Sakaguchi, Kengo

    2008-11-15

    Here, we report an efficient one-cycle affinity selection using a natural-protein or random-peptide T7 phage pool for identification of binding proteins or peptides specific for small-molecules. The screening procedure involved a cuvette type 27-MHz quartz-crystal microbalance (QCM) apparatus with introduction of self-assembled monolayer (SAM) for a specific small-molecule immobilization on the gold electrode surface of a sensor chip. Using this apparatus, we attempted an affinity selection of proteins or peptides against synthetic ligand for FK506-binding protein (SLF) or irinotecan (Iri, CPT-11). An affinity selection using SLF-SAM and a natural-protein T7 phage pool successfully detected FK506-binding protein 12 (FKBP12)-displaying T7 phage after an interaction time of only 10 min. Extensive exploration of time-consuming wash and/or elution conditions together with several rounds of selection was not required. Furthermore, in the selection using a 15-mer random-peptide T7 phage pool and subsequent analysis utilizing receptor ligand contact (RELIC) software, a subset of SLF-selected peptides clearly pinpointed several amino-acid residues within the binding site of FKBP12. Likewise, a subset of Iri-selected peptides pinpointed part of the positive amino-acid region of residues from the Iri-binding site of the well-known direct targets, acetylcholinesterase (AChE) and carboxylesterase (CE). Our findings demonstrate the effectiveness of this method and general applicability for a wide range of small-molecules.

  4. Quality of life in female myocardial infarction survivors: a comparative study with a randomly selected general female population cohort.

    PubMed

    Norekvål, Tone M; Wahl, Astrid K; Fridlund, Bengt; Nordrehaug, Jan E; Wentzel-Larsen, Tore; Hanestad, Berit R

    2007-10-30

    A substantial burden associated with MI has been reported. Thus, how survivors experience their quality of life (QOL) is now being given increasing attention. However, few studies have involved women and a comparison with the general population. The aims of this study were to determine the QOL of female MI survivors, to investigate whether their QOL differed from that of the general population, and to evaluate the clinical significance of the findings. Two cross-sectional surveys were performed; on female MI survivors and the general Norwegian population. The MI survey included women aged 62-80 years, three months to five years after their MI. One hundred and forty-five women responded, yielding a response rate of 60%. A subset of women in the same age range (n = 156) was drawn from a study of 1893 randomly selected Norwegian citizens. QOL was measured in both groups with the World Health Organization Quality of Life Instrument Abbreviated (WHOQOL-BREF). The majority (54%) of the female MI survivors presented with ST-elevation in their ECG, 31% received thrombolysis, and 38% had reduced left ventricular ejection fraction. Female MI survivors reported significantly lower satisfaction with general health (p = 0.020) and overall QOL (p = 0.017) than women from the general population. This was also the case for the physical and environmental QOL domains (p < 0.001), but not for the psychological and social relationship domains. Estimated effect sizes between the two groups of participants ranged from 0.1 to -0.6. The burden of MI significantly affects the physical health of elderly women. Still, female MI survivors fare as well as the general female population on psychosocial QOL domains. Action should be taken not only to support women's physical needs but also to reinforce their strengths in order to maintain optimal QOL.

  5. Quality of life in female myocardial infarction survivors: a comparative study with a randomly selected general female population cohort

    PubMed Central

    Norekvål, Tone M; Wahl, Astrid K; Fridlund, Bengt; Nordrehaug, Jan E; Wentzel-Larsen, Tore; Hanestad, Berit R

    2007-01-01

    Background A substantial burden associated with MI has been reported. Thus, how survivors experience their quality of life (QOL) is now being given increasing attention. However, few studies have involved women and a comparison with the general population. The aims of this study were to determine the QOL of female MI survivors, to investigate whether their QOL differed from that of the general population, and to evaluate the clinical significance of the findings. Methods Two cross-sectional surveys were performed; on female MI survivors and the general Norwegian population. The MI survey included women aged 62–80 years, three months to five years after their MI. One hundred and forty-five women responded, yielding a response rate of 60%. A subset of women in the same age range (n = 156) was drawn from a study of 1893 randomly selected Norwegian citizens. QOL was measured in both groups with the World Health Organization Quality of Life Instrument Abbreviated (WHOQOL-BREF). Results The majority (54%) of the female MI survivors presented with ST-elevation in their ECG, 31% received thrombolysis, and 38% had reduced left ventricular ejection fraction. Female MI survivors reported significantly lower satisfaction with general health (p = 0.020) and overall QOL (p = 0.017) than women from the general population. This was also the case for the physical and environmental QOL domains (p < 0.001), but not for the psychological and social relationship domains. Estimated effect sizes between the two groups of participants ranged from 0.1 to -0.6. Conclusion The burden of MI significantly affects the physical health of elderly women. Still, female MI survivors fare as well as the general female population on psychosocial QOL domains. Action should be taken not only to support women's physical needs but also to reinforce their strengths in order to maintain optimal QOL. PMID:17971206

  6. A randomized evaluation of a computer-based physician's workstation: design considerations and baseline results.

    PubMed Central

    Rotman, B. L.; Sullivan, A. N.; McDonald, T.; DeSmedt, P.; Goodnature, D.; Higgins, M.; Suermondt, H. J.; Young, C. Y.; Owens, D. K.

    1995-01-01

    We are performing a randomized, controlled trial of a Physician's Workstation (PWS), an ambulatory care information system, developed for use in the General Medical Clinic (GMC) of the Palo Alto VA. Goals for the project include selecting appropriate outcome variables and developing a statistically powerful experimental design with a limited number of subjects. As PWS provides real-time drug-ordering advice, we retrospectively examined drug costs and drug-drug interactions in order to select outcome variables sensitive to our short-term intervention as well as to estimate the statistical efficiency of alternative design possibilities. Drug cost data revealed the mean daily cost per physician per patient was 99.3 cents +/- 13.4 cents, with a range from 0.77 cent to 1.37 cents. The rate of major interactions per prescription for each physician was 2.9% +/- 1%, with a range from 1.5% to 4.8%. Based on these baseline analyses, we selected a two-period parallel design for the evaluation, which maximized statistical power while minimizing sources of bias. PMID:8563376

  7. Intrarater repeatability of shade selections with two shade guides.

    PubMed

    Hammad, Ihab A

    2003-01-01

    Color research has shown that shade guides do not always represent the color of natural teeth. Moreover, visual evaluation has been found to be unreliable and inconsistent. This investigation evaluated the effects of 2 shade guides on the intrarater repeatability (reliability) of prosthodontists and general practitioners with regard to shade selection. Ten prosthodontists and ten general practitioners (all men, 35-45 years old) with an average practice experience of 14 years participated in this study. Examiners were tested to eliminate color blindness. Each clinician used Vita Lumin Vacuum and Vitapan 3D-Master shade guides to determine the shades of the maxillary right canines of 20 patients following a standard protocol. The identification codes of the shade tabs were masked to prevent shade memory. All teeth were polished before each shade selection, and the selection process was standardized for controlled lighting and procedures. Shade selections were randomly repeated 1 month later by the same practitioners on the same group of patients in accordance with the same shade-selection protocol. Analysis of variance and t tests for individual comparisons among means were performed (P<.05). Significant interactions were found between the effects of shade guide system and specialty training on intrarater repeatability (P<.0001, analysis of variance). The intrarater repeatability of prosthodontists was significantly higher than that of general practitioners when the Vita Lumin Vacuum shade guide was used (P<.0001, t test). Use of the Vitapan 3D-Master shade guide significantly improved the intrarater repeatability of general practitioners compared with the Vita Lumin Vacuum shade guide (P<.0005). This improvement was not significant, however, among prosthodontists (P=.2861). Within the limitations of this study, the prosthodontists demonstrated superior intrarater repeatability in shade selection, especially when the Vita Lumin Vacuum shade guide was used. Use of the Vitapan 3D-Master shade guide notably improved intrarater repeatability among the general practitioners.

  8. Improving general practitioner clinical records with a quality assurance minimal intervention.

    PubMed Central

    Del Mar, C B; Lowe, J B; Adkins, P; Arnold, E; Baade, P

    1998-01-01

    BACKGROUND: Although good medical records have been associated with good care, there is considerable room for their improvement in general practice. AIM: To improve the quality of general practice medical records at minimal cost. METHOD: A total of 150 randomly sampled general practitioners (GPs) in suburban Brisbane, Australia, were randomized in a controlled trial to receive or not receive an intervention. The intervention consisted of 6 to 12 one-hour monthly meetings when the pairs of GPs assessed samples of each other's medical records using a 12-item instrument. This was developed previously by a process of consensus of general practice teachers. Mean scores of 10 medical records selected at random from before the intervention started and one year later were compared. RESULTS: After the intervention, the increase in the total score (for which the maximum possible was 18) for the intervention GPs (from a baseline of 11.5 to 12.3) was not significantly greater than for the controls (from 11.4 to 11.7). Legibility and being able to determine the doctor's assessment of the consultation were significantly improved. The post-intervention increase of 1.06 (9.3%) of the total scores of the 47% of intervention GPs who complied with the intervention was significantly greater than that for the controls. CONCLUSION: The quality assurance activity improved some components of the quality of GPs' clinical records. However, the improvement was small, and the search for activities for Australian GPs that demonstrate an improvement in the quality of their practice must continue. Images p1311-a PMID:9747547

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peressutti, D; Schipaanboord, B; Kadir, T

    Purpose: To investigate the effectiveness of atlas selection methods for improving atlas-based auto-contouring in radiotherapy planning. Methods: 275 H&N clinically delineated cases were employed as an atlas database from which atlases would be selected. A further 40 previously contoured cases were used as test patients against which atlas selection could be performed and evaluated. 26 variations of selection methods proposed in the literature and used in commercial systems were investigated. Atlas selection methods comprised either global or local image similarity measures, computed after rigid or deformable registration, combined with direct atlas search or with an intermediate template image. Workflow Boxmore » (Mirada-Medical, Oxford, UK) was used for all auto-contouring. Results on brain, brainstem, parotids and spinal cord were compared to random selection, a fixed set of 10 “good” atlases, and optimal selection by an “oracle” with knowledge of the ground truth. The Dice score and the average ranking with respect to the “oracle” were employed to assess the performance of the top 10 atlases selected by each method. Results: The fixed set of “good” atlases outperformed all of the atlas-patient image similarity-based selection methods (mean Dice 0.715 c.f. 0.603 to 0.677). In general, methods based on exhaustive comparison of local similarity measures showed better average Dice scores (0.658 to 0.677) compared to the use of either template image (0.655 to 0.672) or global similarity measures (0.603 to 0.666). The performance of image-based selection methods was found to be only slightly better than a random (0.645). Dice scores given relate to the left parotid, but similar results patterns were observed for all organs. Conclusion: Intuitively, atlas selection based on the patient CT is expected to improve auto-contouring performance. However, it was found that published approaches performed marginally better than random and use of a fixed set of representative atlases showed favourable performance. This research was funded via InnovateUK Grant 600277 as part of Eurostars Grant E!9297. DP,BS,MG,TK are employees of Mirada Medical Ltd.« less

  10. Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2000: A stratified random approach

    USGS Publications Warehouse

    Carter, J.; Merino, J.H.; Merino, S.L.

    2009-01-01

    Estimates of submerged aquatic vegetative (SAV) along the U.S. Gulf of Mexico (Gulf) generally focus on seagrasses. In 2000, we attempted a synoptic survey of SAV in the mesohaline (5-20 ppt) zone of estuarine and nearshore areas of the northeastern Gulf. Areas with SAV were identified from existing aerial 1992 photography, and a literature review was used to select those areas that were likely to experience mesohaline conditions during the growing season. In 2000, a drought year, we visited 217 randomly selected SAV beds and collected data on species composition and environmental conditions. In general, sites were either clearly polyhaline (2: 20 ppt) or oligohaline (S 5 ppt), with only five sites measuring between 5 and 20 ppt. Ruppia maritima L. (13-35 ppt, n = 28) was the only species that occurred in mesohaline salinities. Halodule wrightii Asch. occurred in 73% of the beds. The nonindigenous Myriophyllum spicatum L. was present in four locations with salinities below 3 ppt. No nonindigenous macroalgae were identified, and no nonindigenous angiosperms occurred in salinities above 3 ppt. Selecting sample locations based on historical salinity data was not a successful strategy for surveying SAV in mesohaline systems, particularly during a drought year. Our ability to locate SAV beds within 50 m of their aerially located position 8 yr later demonstrates some SAV stability in the highly variable conditions of the study area. ?? 2009 by the Marine Environmental Silences Consortium of Alabama.

  11. Effect of anger management education on mental health and aggression of prisoner women

    PubMed Central

    Bahrami, Elaheh; Mazaheri, Maryam Amidi; Hasanzadeh, Akbar

    2016-01-01

    Background and Purpose: “Uncontrolled anger” threats the compatible and health of people as serious risk. The effects of weaknesses and shortcomings in the management of anger, from personal distress and destruction interpersonal relationships beyond and linked to the public health problems, lack of compromises, and aggressive behavior adverse outcomes. This study investigates the effects of anger management education on mental health and aggression of prisoner women in Isfahan. Materials and Methods: The single-group quasi-experimental (pretest, posttest) by prisoner women in the central prison of Isfahan was done. Multi-stage random sampling method was used. Initially, 165 women were selected randomly and completed the Buss and Perry Aggression Questionnaire and the General Health Questionnaire-28, and among these, those with scores >78 (the cut point) in aggression scale was selected and among them 70 were randomly selected. In the next step, interventions in four 90 min training sessions were conducted. Posttest was performed within 1-month after the intervention. Data were analyzed using SPSS-20 software. Results: Data analysis showed that anger management training was effective in reducing aggression (P < 0.001) and also had a positive effect on mental health (P < 0.001). Conclusion: According to the importance of aggression in consistency and individual and collective health and according to findings, presented educational programs on anger management is essential for female prisoners. PMID:27512697

  12. A Bayesian random effects discrete-choice model for resource selection: Population-level selection inference

    USGS Publications Warehouse

    Thomas, D.L.; Johnson, D.; Griffith, B.

    2006-01-01

    Modeling the probability of use of land units characterized by discrete and continuous measures, we present a Bayesian random-effects model to assess resource selection. This model provides simultaneous estimation of both individual- and population-level selection. Deviance information criterion (DIC), a Bayesian alternative to AIC that is sample-size specific, is used for model selection. Aerial radiolocation data from 76 adult female caribou (Rangifer tarandus) and calf pairs during 1 year on an Arctic coastal plain calving ground were used to illustrate models and assess population-level selection of landscape attributes, as well as individual heterogeneity of selection. Landscape attributes included elevation, NDVI (a measure of forage greenness), and land cover-type classification. Results from the first of a 2-stage model-selection procedure indicated that there is substantial heterogeneity among cow-calf pairs with respect to selection of the landscape attributes. In the second stage, selection of models with heterogeneity included indicated that at the population-level, NDVI and land cover class were significant attributes for selection of different landscapes by pairs on the calving ground. Population-level selection coefficients indicate that the pairs generally select landscapes with higher levels of NDVI, but the relationship is quadratic. The highest rate of selection occurs at values of NDVI less than the maximum observed. Results for land cover-class selections coefficients indicate that wet sedge, moist sedge, herbaceous tussock tundra, and shrub tussock tundra are selected at approximately the same rate, while alpine and sparsely vegetated landscapes are selected at a lower rate. Furthermore, the variability in selection by individual caribou for moist sedge and sparsely vegetated landscapes is large relative to the variability in selection of other land cover types. The example analysis illustrates that, while sometimes computationally intense, a Bayesian hierarchical discrete-choice model for resource selection can provide managers with 2 components of population-level inference: average population selection and variability of selection. Both components are necessary to make sound management decisions based on animal selection.

  13. Territory and nest site selection patterns by Grasshopper Sparrows in southeastern Arizona

    USGS Publications Warehouse

    Ruth, Janet M.; Skagen, Susan K.

    2017-01-01

    Grassland bird populations are showing some of the greatest rates of decline of any North American birds, prompting measures to protect and improve important habitat. We assessed how vegetation structure and composition, habitat features often targeted for management, affected territory and nest site selection by Grasshopper Sparrows (Ammodramus savannarum ammolegus) in southeastern Arizona. To identify features important to males establishing territories, we compared vegetation characteristics of known territories and random samples on 2 sites over 5 years. We examined habitat selection patterns of females by comparing characteristics of nest sites with territories over 3 years. Males selected territories in areas of sparser vegetation structure and more tall shrubs (>2 m) than random plots on the site with low shrub densities. Males did not select territories based on the proportion of exotic grasses. Females generally located nest sites in areas with lower small shrub (1–2 m tall) densities than territories overall when possible and preferentially selected native grasses for nest construction. Whether habitat selection was apparent depended upon the range of vegetation structure that was available. We identified an upper threshold above which grass structure seemed to be too high and dense for Grasshopper Sparrows. Our results suggest that some management that reduces vegetative structure may benefit this species in desert grasslands at the nest and territory scale. However, we did not assess initial male habitat selection at a broader landscape scale where their selection patterns may be different and could be influenced by vegetation density and structure outside the range of values sampled in this study.

  14. Selection of examples in case-based computer-aided decision systems

    PubMed Central

    Mazurowski, Maciej A.; Zurada, Jacek M.; Tourassi, Georgia D.

    2013-01-01

    Case-based computer-aided decision (CB-CAD) systems rely on a database of previously stored, known examples when classifying new, incoming queries. Such systems can be particularly useful since they do not need retraining every time a new example is deposited in the case base. The adaptive nature of case-based systems is well suited to the current trend of continuously expanding digital databases in the medical domain. To maintain efficiency, however, such systems need sophisticated strategies to effectively manage the available evidence database. In this paper, we discuss the general problem of building an evidence database by selecting the most useful examples to store while satisfying existing storage requirements. We evaluate three intelligent techniques for this purpose: genetic algorithm-based selection, greedy selection and random mutation hill climbing. These techniques are compared to a random selection strategy used as the baseline. The study is performed with a previously presented CB-CAD system applied for false positive reduction in screening mammograms. The experimental evaluation shows that when the development goal is to maximize the system’s diagnostic performance, the intelligent techniques are able to reduce the size of the evidence database to 37% of the original database by eliminating superfluous and/or detrimental examples while at the same time significantly improving the CAD system’s performance. Furthermore, if the case-base size is a main concern, the total number of examples stored in the system can be reduced to only 2–4% of the original database without a decrease in the diagnostic performance. Comparison of the techniques shows that random mutation hill climbing provides the best balance between the diagnostic performance and computational efficiency when building the evidence database of the CB-CAD system. PMID:18854606

  15. A Probabilistic Approach to Uncertainty Analysis in NTPR Radiation Dose Assessments

    DTIC Science & Technology

    2009-11-01

    Zeman, members of the Subcommittee on Dose Reconstruction of the Veterans’ Advisory Board on Dose Reconstruction (VBDR) for their critical review of...production and decay of fission products, activation products, and actinides . (It is generally assumed in these calculations that no 30 Time...histories”), and on each history selecting random values from each of the pdf’s, they were able to conduct “numerical experiments” and derive critical

  16. Do the Hard Things First: A Randomized Controlled Trial Testing the Effects of Exemplar Selection on Generalization Following Therapy for Grammatical Morphology

    ERIC Educational Resources Information Center

    Van Horne, Amanda Jean Owen; Fey, Marc; Curran, Maura

    2017-01-01

    Purpose: Complexity-based approaches to treatment have been gaining popularity in domains such as phonology and aphasia but have not yet been tested in child morphological acquisition. In this study, we examined whether beginning treatment with easier-to-inflect (easy first) or harder-to-inflect (hard first) verbs led to greater progress in the…

  17. Effect of the federal estate tax on nonindustrial private forest holdings

    Treesearch

    John L. Greene; Steven H. Bullard; Tamara L. Cushing; Theodore Beauvais

    2006-01-01

    Data for this study were collected using a questionnaire mailed to randomly selected members of two forest owner organizations. Among the key findings is that 38% of forest estates owed federal estate tax, a rate many times higher than US estates in general. In 28% of the cases where estate tax was due, timber or land was sold because other assets were not adequate. In...

  18. Private Sector Providers of Basic Skills Training in the Workplace. A Study of the General Training and Basic Skills Responses of Randomly Selected Companies Which Provide Basic Skills Training to Their Employees.

    ERIC Educational Resources Information Center

    Mark, Jorie Lester

    A questionnaire was distributed to 1,305 companies to study the basic skills training provided. Of 62 responses, 41 companies had basic skills training programs. Respondents represented these types of companies: communications and utilities, finance and insurance, manufacturing, wholesalers, retailers, health and hospitals, and mining, and had…

  19. Search Algorithms as a Framework for the Optimization of Drug Combinations

    PubMed Central

    Coquin, Laurence; Schofield, Jennifer; Feala, Jacob D.; Reed, John C.; McCulloch, Andrew D.; Paternostro, Giovanni

    2008-01-01

    Combination therapies are often needed for effective clinical outcomes in the management of complex diseases, but presently they are generally based on empirical clinical experience. Here we suggest a novel application of search algorithms—originally developed for digital communication—modified to optimize combinations of therapeutic interventions. In biological experiments measuring the restoration of the decline with age in heart function and exercise capacity in Drosophila melanogaster, we found that search algorithms correctly identified optimal combinations of four drugs using only one-third of the tests performed in a fully factorial search. In experiments identifying combinations of three doses of up to six drugs for selective killing of human cancer cells, search algorithms resulted in a highly significant enrichment of selective combinations compared with random searches. In simulations using a network model of cell death, we found that the search algorithms identified the optimal combinations of 6–9 interventions in 80–90% of tests, compared with 15–30% for an equivalent random search. These findings suggest that modified search algorithms from information theory have the potential to enhance the discovery of novel therapeutic drug combinations. This report also helps to frame a biomedical problem that will benefit from an interdisciplinary effort and suggests a general strategy for its solution. PMID:19112483

  20. Dynamics of transit times and StorAge Selection functions in four forested catchments from stable isotope data

    NASA Astrophysics Data System (ADS)

    Rodriguez, Nicolas B.; McGuire, Kevin J.; Klaus, Julian

    2017-04-01

    Transit time distributions, residence time distributions and StorAge Selection functions are fundamental integrated descriptors of water storage, mixing, and release in catchments. In this contribution, we determined these time-variant functions in four neighboring forested catchments in H.J. Andrews Experimental Forest, Oregon, USA by employing a two year time series of 18O in precipitation and discharge. Previous studies in these catchments assumed stationary, exponentially distributed transit times, and complete mixing/random sampling to explore the influence of various catchment properties on the mean transit time. Here we relaxed such assumptions to relate transit time dynamics and the variability of StoreAge Selection functions to catchment characteristics, catchment storage, and meteorological forcing seasonality. Conceptual models of the catchments, consisting of two reservoirs combined in series-parallel, were calibrated to discharge and stable isotope tracer data. We assumed randomly sampled/fully mixed conditions for each reservoir, which resulted in an incompletely mixed system overall. Based on the results we solved the Master Equation, which describes the dynamics of water ages in storage and in catchment outflows Consistent between all catchments, we found that transit times were generally shorter during wet periods, indicating the contribution of shallow storage (soil, saprolite) to discharge. During extended dry periods, transit times increased significantly indicating the contribution of deeper storage (bedrock) to discharge. Our work indicated that the strong seasonality of precipitation impacted transit times by leading to a dynamic selection of stored water ages, whereas catchment size was not a control on transit times. In general this work showed the usefulness of using time-variant transit times with conceptual models and confirmed the existence of the catchment age mixing behaviors emerging from other similar studies.

  1. How random is a random vector?

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2015-12-01

    Over 80 years ago Samuel Wilks proposed that the "generalized variance" of a random vector is the determinant of its covariance matrix. To date, the notion and use of the generalized variance is confined only to very specific niches in statistics. In this paper we establish that the "Wilks standard deviation" -the square root of the generalized variance-is indeed the standard deviation of a random vector. We further establish that the "uncorrelation index" -a derivative of the Wilks standard deviation-is a measure of the overall correlation between the components of a random vector. Both the Wilks standard deviation and the uncorrelation index are, respectively, special cases of two general notions that we introduce: "randomness measures" and "independence indices" of random vectors. In turn, these general notions give rise to "randomness diagrams"-tangible planar visualizations that answer the question: How random is a random vector? The notion of "independence indices" yields a novel measure of correlation for Lévy laws. In general, the concepts and results presented in this paper are applicable to any field of science and engineering with random-vectors empirical data.

  2. Engineering RNA phage MS2 virus-like particles for peptide display

    NASA Astrophysics Data System (ADS)

    Jordan, Sheldon Keith

    Phage display is a powerful and versatile technology that enables the selection of novel binding functions from large populations of randomly generated peptide sequences. Random sequences are genetically fused to a viral structural protein to produce complex peptide libraries. From a sufficiently complex library, phage bearing peptides with practically any desired binding activity can be physically isolated by affinity selection, and, since each particle carries in its genome the genetic information for its own replication, the selectants can be amplified by infection of bacteria. For certain applications however, existing phage display platforms have limitations. One such area is in the field of vaccine development, where the goal is to identify relevant epitopes by affinity-selection against an antibody target, and then to utilize them as immunogens to elicit a desired antibody response. Today, affinity selection is usually conducted using display on filamentous phages like M13. This technology provides an efficient means for epitope identification, but, because filamentous phages do not display peptides in the high-density, multivalent arrays the immune system prefers to recognize, they generally make poor immunogens and are typically useless as vaccines. This makes it necessary to confer immunogenicity by conjugating synthetic versions of the peptides to more immunogenic carriers. Unfortunately, when introduced into these new structural environments, the epitopes often fail to elicit relevant antibody responses. Thus, it would be advantageous to combine the epitope selection and immunogen functions into a single platform where the structural constraints present during affinity selection can be preserved during immunization. This dissertation describes efforts to develop a peptide display system based on the virus-like particles (VLPs) of bacteriophage MS2. Phage display technologies rely on (1) the identification of a site in a viral structural protein that is present on the surface of the virus particle and can accept foreign sequence insertions without disruption of protein folding and viral particle assembly, and (2) on the encapsidation of nucleic acid sequences encoding both the VLP and the peptide it displays. The experiments described here are aimed at satisfying the first of these two requirements by engineering efficient peptide display at two different sites in MS2 coat protein. First, we evaluated the suitability of the N-terminus of MS2 coat for peptide insertions. It was observed that random N-terminal 10-mer fusions generally disrupted protein folding and VLP assembly, but by bracketing the foreign sequences with certain specific dipeptides, these defects could be suppressed. Next, the suitability of a coat protein surface loop for foreign sequence insertion was tested. Specifically, random sequence peptides were inserted into the N-terminal-most AB-loop of a coat protein single-chain dimer. Again we found that efficient display required the presence of appropriate dipeptides bracketing the peptide insertion. Finally, it was shown that an N-terminal fusion that tended to interfere specifically with capsid assembly could be efficiently incorporated into mosaic particles when co-expressed with wild-type coat protein.

  3. Feature Selection for Ridge Regression with Provable Guarantees.

    PubMed

    Paul, Saurabh; Drineas, Petros

    2016-04-01

    We introduce single-set spectral sparsification as a deterministic sampling-based feature selection technique for regularized least-squares classification, which is the classification analog to ridge regression. The method is unsupervised and gives worst-case guarantees of the generalization power of the classification function after feature selection with respect to the classification function obtained using all features. We also introduce leverage-score sampling as an unsupervised randomized feature selection method for ridge regression. We provide risk bounds for both single-set spectral sparsification and leverage-score sampling on ridge regression in the fixed design setting and show that the risk in the sampled space is comparable to the risk in the full-feature space. We perform experiments on synthetic and real-world data sets; a subset of TechTC-300 data sets, to support our theory. Experimental results indicate that the proposed methods perform better than the existing feature selection methods.

  4. COMPARISON OF RANDOM AND SYSTEMATIC SITE SELECTION FOR ASSESSING ATTAINMENT OF AQUATIC LIFE USES IN SEGMENTS OF THE OHIO RIVER

    EPA Science Inventory

    This report is a description of field work and data analysis results comparing a design comparable to systematic site selection with one based on random selection of sites. The report is expected to validate the use of random site selection in the bioassessment program for the O...

  5. Interbank lending, network structure and default risk contagion

    NASA Astrophysics Data System (ADS)

    Zhang, Minghui; He, Jianmin; Li, Shouwei

    2018-03-01

    This paper studies the default risk contagion in banking systems based on a dynamic network model with two different kinds of lenders' selecting mechanisms, namely, endogenous selecting (ES) and random selecting (RS). From sensitivity analysis, we find that higher risk premium, lower initial proportion of net assets, higher liquid assets threshold, larger size of liquidity shocks, higher proportion of the initial investments and higher Central Bank interest rates all lead to severer default risk contagion. Moreover, the autocorrelation of deposits and lenders' selecting probability have non-monotonic effects on the default risk contagion, and the effects differ under two mechanisms. Generally, the default risk contagion is much severer under RS mechanism than that of ES, because the multi-money-center structure generated by ES mechanism enables borrowers to borrow from more liquid banks with lower interest rates.

  6. Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study

    PubMed Central

    Hammitt, Laura L.; Deloria Knoll, Maria; Baggett, Henry C.; Brooks, W. Abdullah; Howie, Stephen R. C.; Kotloff, Karen L.; Levine, Orin S.; Madhi, Shabir A.; Murdoch, David R.; Scott, J. Anthony G.; Thea, Donald M.; Driscoll, Amanda J.; Karron, Ruth A.; Park, Daniel E.; Prosperi, Christine; Zeger, Scott L.; O’Brien, Katherine L.; Feikin, Daniel R.; O’Brien, Katherine L.; Levine, Orin S.; Knoll, Maria Deloria; Feikin, Daniel R.; DeLuca, Andrea N.; Driscoll, Amanda J.; Fu, Wei; Hammitt, Laura L.; Higdon, Melissa M.; Kagucia, E. Wangeci; Karron, Ruth A.; Li, Mengying; Park, Daniel E.; Prosperi, Christine; Wu, Zhenke; Zeger, Scott L.; Watson, Nora L.; Crawley, Jane; Murdoch, David R.; Brooks, W. Abdullah; Endtz, Hubert P.; Zaman, Khalequ; Goswami, Doli; Hossain, Lokman; Jahan, Yasmin; Ashraf, Hasan; Howie, Stephen R. C.; Ebruke, Bernard E.; Antonio, Martin; McLellan, Jessica; Machuka, Eunice; Shamsul, Arifin; Zaman, Syed M.A.; Mackenzie, Grant; Scott, J. Anthony G.; Awori, Juliet O.; Morpeth, Susan C.; Kamau, Alice; Kazungu, Sidi; Kotloff, Karen L.; Tapia, Milagritos D.; Sow, Samba O.; Sylla, Mamadou; Tamboura, Boubou; Onwuchekwa, Uma; Kourouma, Nana; Toure, Aliou; Madhi, Shabir A.; Moore, David P.; Adrian, Peter V.; Baillie, Vicky L.; Kuwanda, Locadiah; Mudau, Azwifarwi; Groome, Michelle J.; Baggett, Henry C.; Thamthitiwat, Somsak; Maloney, Susan A.; Bunthi, Charatdao; Rhodes, Julia; Sawatwong, Pongpun; Akarasewi, Pasakorn; Thea, Donald M.; Mwananyanda, Lawrence; Chipeta, James; Seidenberg, Phil; Mwansa, James; wa Somwe, Somwe; Kwenda, Geoffrey

    2017-01-01

    Abstract Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. PMID:28575354

  7. Presentation and antimicrobial treatment of acute orofacial infections in general dental practice.

    PubMed

    Lewis, M A; Meechan, C; MacFarlane, T W; Lamey, P J; Kay, E

    1989-01-21

    Information on the presentation of orofacial infections and the use of antimicrobial agents in general dental practice in the United Kingdom was obtained using a postal questionnaire. Six hundred dentists were randomly selected and a total of 340 replies were received, giving a response rate of 57%. The dental practitioners estimated that acute infection was present in only a minority (approximately 5%) of patients. A total of seven different antibiotics were prescribed, in a variety of regimens, for the treatment of bacterial infection. However, the majority of dentists (46-62%) preferred a 5-day course of penicillin (250 mg, qid) for bacterial conditions other than acute ulcerative gingivitis, for which most practitioners (89%) prescribed 3 days of metronidazole (200 mg, tid). Nystatin was the most frequently selected anticandidal agent and topical acyclovir the most popular therapy for Herpes simplex infection.

  8. Bioinformatic Analysis of the Contribution of Primer Sequences to Aptamer Structures

    PubMed Central

    Ellington, Andrew D.

    2009-01-01

    Aptamers are nucleic acid molecules selected in vitro to bind a particular ligand. While numerous experimental studies have examined the sequences, structures, and functions of individual aptamers, considerably fewer studies have applied bioinformatics approaches to try to infer more general principles from these individual studies. We have used a large Aptamer Database to parse the contributions of both random and constant regions to the secondary structures of more than 2000 aptamers. We find that the constant, primer-binding regions do not, in general, contribute significantly to aptamer structures. These results suggest that (a) binding function is not contributed to nor constrained by constant regions; (b) in consequence, the landscape of functional binding sequences is sparse but robust, favoring scenarios for short, functional nucleic acid sequences near origins; and (c) many pool designs for the selection of aptamers are likely to prove robust. PMID:18594898

  9. Is extreme learning machine feasible? A theoretical assessment (part II).

    PubMed

    Lin, Shaobo; Liu, Xia; Fang, Jian; Xu, Zongben

    2015-01-01

    An extreme learning machine (ELM) can be regarded as a two-stage feed-forward neural network (FNN) learning system that randomly assigns the connections with and within hidden neurons in the first stage and tunes the connections with output neurons in the second stage. Therefore, ELM training is essentially a linear learning problem, which significantly reduces the computational burden. Numerous applications show that such a computation burden reduction does not degrade the generalization capability. It has, however, been open that whether this is true in theory. The aim of this paper is to study the theoretical feasibility of ELM by analyzing the pros and cons of ELM. In the previous part of this topic, we pointed out that via appropriately selected activation functions, ELM does not degrade the generalization capability in the sense of expectation. In this paper, we launch the study in a different direction and show that the randomness of ELM also leads to certain negative consequences. On one hand, we find that the randomness causes an additional uncertainty problem of ELM, both in approximation and learning. On the other hand, we theoretically justify that there also exist activation functions such that the corresponding ELM degrades the generalization capability. In particular, we prove that the generalization capability of ELM with Gaussian kernel is essentially worse than that of FNN with Gaussian kernel. To facilitate the use of ELM, we also provide a remedy to such a degradation. We find that the well-developed coefficient regularization technique can essentially improve the generalization capability. The obtained results reveal the essential characteristic of ELM in a certain sense and give theoretical guidance concerning how to use ELM.

  10. Non-urban mobile radio market demand forecast

    NASA Technical Reports Server (NTRS)

    Castruccio, P. A.; Cooper, J.

    1982-01-01

    A national nonmetropolitan land mobile traffic model for 1990-2000 addresses user classes, density classes, traffic mix statistics, distance distribution, geographic distribution, price elasticity, and service quality elasticity. Traffic demands for business, special industrial, and police were determined on the basis of surveys in 73 randomly selected nonurban counties. The selected services represent 69% of total demand. The results were extrapolated to all services in the non-SMSA areas of the contiguous United States. Radiotelephone services were considered separately. Total non-SMSA mobile radio demand (one way) estimates are given. General functional requirements include: hand portability, privacy, reduction of blind spots, two way data transmission, position location, slow scan imagery.

  11. Amygdala Reactivity to Emotional Faces in the Prediction of General and Medication-Specific Responses to Antidepressant Treatment in the Randomized iSPOT-D Trial.

    PubMed

    Williams, Leanne M; Korgaonkar, Mayuresh S; Song, Yun C; Paton, Rebecca; Eagles, Sarah; Goldstein-Piekarski, Andrea; Grieve, Stuart M; Harris, Anthony W F; Usherwood, Tim; Etkin, Amit

    2015-09-01

    Although the cost of poor treatment outcomes of depression is staggering, we do not yet have clinically useful methods for selecting the most effective antidepressant for each depressed person. Emotional brain activation is altered in major depressive disorder (MDD) and implicated in treatment response. Identifying which aspects of emotional brain activation are predictive of general and specific responses to antidepressants may help clinicians and patients when making treatment decisions. We examined whether amygdala activation probed by emotion stimuli is a general or differential predictor of response to three commonly prescribed antidepressants, using functional magnetic resonance imaging (fMRI). A test-retest design was used to assess patients with MDD in an academic setting as part of the International Study to Predict Optimized Treatment in Depression. A total of 80 MDD outpatients were scanned prior to treatment and 8 weeks after randomization to the selective serotonin reuptake inhibitors escitalopram and sertraline and the serotonin-norepinephrine reuptake inhibitor, venlafaxine-extended release (XR). A total of 34 matched controls were scanned at the same timepoints. We quantified the blood oxygen level-dependent signal of the amygdala during subliminal and supraliminal viewing of facial expressions of emotion. Response to treatment was defined by ⩾50% symptom improvement on the 17-item Hamilton Depression Rating Scale. Pre-treatment amygdala hypo-reactivity to subliminal happy and threat was a general predictor of treatment response, regardless of medication type (Cohen's d effect size 0.63 to 0.77; classification accuracy, 75%). Responders showed hypo-reactivity compared to controls at baseline, and an increase toward 'normalization' post-treatment. Pre-treatment amygdala reactivity to subliminal sadness was a differential moderator of non-response to venlafaxine-XR (Cohen's d effect size 1.5; classification accuracy, 81%). Non-responders to venlafaxine-XR showed pre-treatment hyper-reactivity, which progressed to hypo-reactivity rather than normalization post-treatment, and hypo-reactivity post-treatment was abnormal compared to controls. Impaired amygdala activation has not previously been highlighted in the general vs differential prediction of antidepressant outcomes. Amygdala hypo-reactivity to emotions signaling reward and threat predicts the general capacity to respond to antidepressants. Amygdala hyper-reactivity to sad emotion is involved in a specific non-response to a serotonin-norepinephrine reuptake inhibitor. The findings suggest amygdala probes may help inform the personal selection of antidepressant treatments.

  12. Excessive daytime sleepiness at work and subjective work performance in the general population and among heavy snorers and patients with obstructive sleep apnea.

    PubMed

    Ulfberg, J; Carter, N; Talbäck, M; Edling, C

    1996-09-01

    To evaluate excessive daytime sleepiness (EDS) at work and effects on reported work performance among men in the general population and male patients suffering from snoring and obstructive sleep apnea syndrome (OSAS). A cross-sectional study of Swedish men between the ages of 30 and 64 years in the county of Kopparberg, in mid-Sweden. A random sample of the general population (n = 285) and consecutive patients referred to a sleep laboratory who fulfilled objective diagnostic criteria (snorers = 289, OSAS = 62) responded to a questionnaire. Responders from the general population were divided into 2 groups, nonsnorers (n = 223) and snorers (n = 62). To validate a question on snoring in the questionnaire, 50 men, randomly selected from the sample of the general population, underwent sleep apnea screening in their homes. The specificity of the questions about snoring was 83% and the sensitivity was 42%. The risk ratios for reporting EDS at work were 4-fold for snorers in the general population, 20-fold for snoring patients, and 40-fold for patients with OSAS as compared with nonsnoring men in the general population. Patients with OSAS and snoring patients both showed increased ratios on measures of difficulties with concentration, learning new tasks, and performing monotonous tasks when compared with nonsnorers. Snoring and sleep apnea were highly associated with excessive EDS at work and subjective work performance problems. The results provide additional evidence that snoring is not merely a nuisance.

  13. Randomizing Roaches: Exploring the "Bugs" of Randomization in Experimental Design

    ERIC Educational Resources Information Center

    Wagler, Amy; Wagler, Ron

    2014-01-01

    Understanding the roles of random selection and random assignment in experimental design is a central learning objective in most introductory statistics courses. This article describes an activity, appropriate for a high school or introductory statistics course, designed to teach the concepts, values and pitfalls of random selection and assignment…

  14. COMMENTS AND OPINIONS OF STUDENTS AT ABINGTON HIGH SCHOOL NORTH CAMPUS CONCERNING THE LIBRARY, A REPORT ON THE RESULTS OF A STUDENT OPINIONNAIRE.

    ERIC Educational Resources Information Center

    LUECKE, FRITZ; SPROESSER, GERRY

    A RANDOMLY SELECTED SAMPLE OF 163 NINTH AND TENTH GRADE STUDENTS WAS ASKED, IN A SERIES OF QUESTIONS, TO EXPRESS THEIR ATTITUDE TOWARD THE SCHOOL LIBRARY. THE RESPONSES TO EACH STATEMENT WERE TALLIED AND PRESENTED AS A NUMBER AND PERCENTAGE. IN GENERAL IT WAS FOUND THAT THE MAJORITY OF THE STUDENTS SPEND SOME OF THEIR INDEPENDENT STUDY TIME IN THE…

  15. A generalized mixed effects model of abundance for mark-resight data when sampling is without replacement

    USGS Publications Warehouse

    McClintock, B.T.; White, Gary C.; Burnham, K.P.; Pryde, M.A.; Thomson, David L.; Cooch, Evan G.; Conroy, Michael J.

    2009-01-01

    In recent years, the mark-resight method for estimating abundance when the number of marked individuals is known has become increasingly popular. By using field-readable bands that may be resighted from a distance, these techniques can be applied to many species, and are particularly useful for relatively small, closed populations. However, due to the different assumptions and general rigidity of the available estimators, researchers must often commit to a particular model without rigorous quantitative justification for model selection based on the data. Here we introduce a nonlinear logit-normal mixed effects model addressing this need for a more generalized framework. Similar to models available for mark-recapture studies, the estimator allows a wide variety of sampling conditions to be parameterized efficiently under a robust sampling design. Resighting rates may be modeled simply or with more complexity by including fixed temporal and random individual heterogeneity effects. Using information theory, the model(s) best supported by the data may be selected from the candidate models proposed. Under this generalized framework, we hope the uncertainty associated with mark-resight model selection will be reduced substantially. We compare our model to other mark-resight abundance estimators when applied to mainland New Zealand robin (Petroica australis) data recently collected in Eglinton Valley, Fiordland National Park and summarize its performance in simulation experiments.

  16. Learning accurate and interpretable models based on regularized random forests regression

    PubMed Central

    2014-01-01

    Background Many biology related research works combine data from multiple sources in an effort to understand the underlying problems. It is important to find and interpret the most important information from these sources. Thus it will be beneficial to have an effective algorithm that can simultaneously extract decision rules and select critical features for good interpretation while preserving the prediction performance. Methods In this study, we focus on regression problems for biological data where target outcomes are continuous. In general, models constructed from linear regression approaches are relatively easy to interpret. However, many practical biological applications are nonlinear in essence where we can hardly find a direct linear relationship between input and output. Nonlinear regression techniques can reveal nonlinear relationship of data, but are generally hard for human to interpret. We propose a rule based regression algorithm that uses 1-norm regularized random forests. The proposed approach simultaneously extracts a small number of rules from generated random forests and eliminates unimportant features. Results We tested the approach on some biological data sets. The proposed approach is able to construct a significantly smaller set of regression rules using a subset of attributes while achieving prediction performance comparable to that of random forests regression. Conclusion It demonstrates high potential in aiding prediction and interpretation of nonlinear relationships of the subject being studied. PMID:25350120

  17. Assessing the quality of reproductive health services in Egypt via exit interviews.

    PubMed

    Zaky, Hassan H M; Khattab, Hind A S; Galal, Dina

    2007-05-01

    This study assesses the quality of reproductive health services using client satisfaction exit interviews among three groups of primary health care units run by the Ministry of Health and Population of Egypt. Each group applied a different model of intervention. The Ministry will use the results in assessing its reproductive health component in the health sector reform program, and benefits from the strengths of other models of intervention. The sample was selected in two stages. First, a stratified random sampling procedure was used to select the health units. Then the sample of female clients in each health unit was selected using the systematic random approach, whereby one in every two women visiting the unit was approached. All women in the sample coming for reproductive health services were included in the analysis. The results showed that reproductive health beneficiaries at the units implementing the new health sector reform program were more satisfied with the quality of services. Still there were various areas where clients showed significant dissatisfaction, such as waiting time, interior furnishings, cleanliness of the units and consultation time. The study showed that the staff of these units did not provide a conductive social environment as other interventions did. A significant proportion of women expressed their intention to go to private physicians owing to their flexible working hours and variety specializations. Beneficiaries were generally more satisfied with the quality of health services after attending the reformed units than the other types of units, but the generalization did not fully apply. Areas of weakness are identified.

  18. Perceived somatic and affective barriers for self-efficacy and physical activity.

    PubMed

    Warner, Lisa M; Wolff, Julia K; Spuling, Svenja M; Wurm, Susanne

    2017-05-01

    According to Bandura's social-cognitive theory, perceptions of somatic and affective barriers are sources of self-efficacy. This longitudinal study compares general indicators of health barriers with measures of perceived somatic and affective barriers to predict self-efficacy and accelerometer-assessed physical activity in a subsample of n = 153 (selected at random from N = 310) community-dwelling German older adults. Perceived somatic and affective barriers longitudinally predicted physical activity mediated by self-efficacy, whereas general health barriers did not. Perceived health barriers to physical activity might be more important than more objective health barriers for older adults' physical activity levels.

  19. Effects of religion and type of religious internalization on the mental health of Iranian adolescents.

    PubMed

    Mazidi, Mohammad; Ostovar, Soghra

    2006-08-01

    This study was designed to assess the effects of religion and two types of religious internalization on the mental health of Iranian adolescents. High school students (82 Moslem and 37 Christian) were selected randomly from four high schools in Shiraz and completed the Religious Self-regulation Questionnaire and the General Health Questionnaire. Analysis showed that main effects of types of religious internalization measured on four subscales of the General Health Questionnaire were significant. Religion was significantly associated only with somatic symptoms. For other scales no main effects of religion, types of religious internalization, or their interactions were significant.

  20. Habitat selection of a declining white-tailed deer herd in the central Black Hills, South Dakota and Wyoming

    NASA Astrophysics Data System (ADS)

    Deperno, Christopher Shannon

    Habitat selection, survival rates, the Black Hills National Forest Habitat Capability Model (HABCAP), and the USDA Forest Service Geographic Information System (GIS) data base were evaluated for a declining white-tailed deer (Odocoileus virginianus dacotensis) herd in the central Black Hills of South Dakota and Wyoming. From July 1993 through July 1996, 73 adult and yearling female and 12 adult and yearling male white-tailed deer were radiocollared and visually monitored. Habitat information was collected at 4,662 white-tailed deer locations and 1,087 random locations. Natural mortality (71%) was the primary cause of female mortality, followed by harvest (22.5%) and accidental causes (6.5%). More females died in spring (53.2%) than in fall (22.6%), winter (14.5%), or summer (9.7%). Male mortality resulted from hunting in fall (66.7%) and natural causes in spring (33.3%). Survival rates for all deer by year were 62.1% in 1993, 51.1% in 1994, 56.4% in 1995, and 53.9% in 1996 and were similar (P = 0.691) across years. During winter, white-tailed deer selected ponderosa pine- (Pinus ponderosa ) deciduous and burned pine cover types. Overstory-understory habitats selected included pine/grass-forb, pine/bearberry (Arctostaphylos uva-ursi), pine/snowberry (Symphoricarpos albus), burned pine/grass-forb, and pine/shrub habitats. Structural stages selected included sapling-pole pine stands with >70% canopy cover, burned pine sapling-pole and saw-timber stands with <40% canopy cover. Bedding locations were represented by saw-timber pine structural stages with >40% canopy cover and all sapling-pole pine structural stages; sapling-pole stands with >70% canopy cover received the greatest use. White-tailed deer primarily fed in pine saw-timber structural stage with less than 40% canopy cover. Overall, selected habitats contained lower amounts of grass/forb, shrubs, and litter than random locations. Male and female deer generally bedded in areas that were characterized by greater horizontal cover than feeding and random sites. When feeding and bedding sites were combined males selected areas that were characterized by greater levels of horizontal cover than females. During summer, white-tailed deer selected pine-deciduous, aspen (Populus tremuloides), aspen-coniferous, spruce (Picea glauca), and spruce-deciduous cover types. Overstory-understory habitats selected included pine/juniper (Juniperus communis), aspen/shrubs, spruce/juniper, and spruce/shrub habitats. Structural stages selected included pine, aspen, and spruce sapling pole stands with all levels (0--40%, 41--70%, 71--100%) of canopy cover. All habitat types (i.e., pine, aspen, and spruce) were used as bedding locations with pine sapling-pole structural stages with >70% canopy cover used most, whereas pine saw-timber structural stage with less than 40% canopy cover was primarily used for feeding. Females bedded in areas that were characterized by greater horizontal cover than feeding and random sites, whereas male feeding sites had greater horizontal cover characteristics than bedding or random locations.

  1. Genetic analyses of protein yield in dairy cows applying random regression models with time-dependent and temperature x humidity-dependent covariates.

    PubMed

    Brügemann, K; Gernand, E; von Borstel, U U; König, S

    2011-08-01

    Data used in the present study included 1,095,980 first-lactation test-day records for protein yield of 154,880 Holstein cows housed on 196 large-scale dairy farms in Germany. Data were recorded between 2002 and 2009 and merged with meteorological data from public weather stations. The maximum distance between each farm and its corresponding weather station was 50 km. Hourly temperature-humidity indexes (THI) were calculated using the mean of hourly measurements of dry bulb temperature and relative humidity. On the phenotypic scale, an increase in THI was generally associated with a decrease in daily protein yield. For genetic analyses, a random regression model was applied using time-dependent (d in milk, DIM) and THI-dependent covariates. Additive genetic and permanent environmental effects were fitted with this random regression model and Legendre polynomials of order 3 for DIM and THI. In addition, the fixed curve was modeled with Legendre polynomials of order 3. Heterogeneous residuals were fitted by dividing DIM into 5 classes, and by dividing THI into 4 classes, resulting in 20 different classes. Additive genetic variances for daily protein yield decreased with increasing degrees of heat stress and were lowest at the beginning of lactation and at extreme THI. Due to higher additive genetic variances, slightly higher permanent environment variances, and similar residual variances, heritabilities were highest for low THI in combination with DIM at the end of lactation. Genetic correlations among individual values for THI were generally >0.90. These trends from the complex random regression model were verified by applying relatively simple bivariate animal models for protein yield measured in 2 THI environments; that is, defining a THI value of 60 as a threshold. These high correlations indicate the absence of any substantial genotype × environment interaction for protein yield. However, heritabilities and additive genetic variances from the random regression model tended to be slightly higher in the THI range corresponding to cows' comfort zone. Selecting such superior environments for progeny testing can contribute to an accurate genetic differentiation among selection candidates. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Simple and Multivariate Relationships Between Spiritual Intelligence with General Health and Happiness.

    PubMed

    Amirian, Mohammad-Elyas; Fazilat-Pour, Masoud

    2016-08-01

    The present study examined simple and multivariate relationships of spiritual intelligence with general health and happiness. The employed method was descriptive and correlational. King's Spiritual Quotient scales, GHQ-28 and Oxford Happiness Inventory, are filled out by a sample consisted of 384 students, which were selected using stratified random sampling from the students of Shahid Bahonar University of Kerman. Data are subjected to descriptive and inferential statistics including correlations and multivariate regressions. Bivariate correlations support positive and significant predictive value of spiritual intelligence toward general health and happiness. Further analysis showed that among the Spiritual Intelligence' subscales, Existential Critical Thinking Predicted General Health and Happiness, reversely. In addition, happiness was positively predicted by generation of personal meaning and transcendental awareness. The findings are discussed in line with the previous studies and the relevant theoretical background.

  3. Black-Box System Testing of Real-Time Embedded Systems Using Random and Search-Based Testing

    NASA Astrophysics Data System (ADS)

    Arcuri, Andrea; Iqbal, Muhammad Zohaib; Briand, Lionel

    Testing real-time embedded systems (RTES) is in many ways challenging. Thousands of test cases can be potentially executed on an industrial RTES. Given the magnitude of testing at the system level, only a fully automated approach can really scale up to test industrial RTES. In this paper we take a black-box approach and model the RTES environment using the UML/MARTE international standard. Our main motivation is to provide a more practical approach to the model-based testing of RTES by allowing system testers, who are often not familiar with the system design but know the application domain well-enough, to model the environment to enable test automation. Environment models can support the automation of three tasks: the code generation of an environment simulator, the selection of test cases, and the evaluation of their expected results (oracles). In this paper, we focus on the second task (test case selection) and investigate three test automation strategies using inputs from UML/MARTE environment models: Random Testing (baseline), Adaptive Random Testing, and Search-Based Testing (using Genetic Algorithms). Based on one industrial case study and three artificial systems, we show how, in general, no technique is better than the others. Which test selection technique to use is determined by the failure rate (testing stage) and the execution time of test cases. Finally, we propose a practical process to combine the use of all three test strategies.

  4. Revisiting the relationship between wages and sleep duration: The role of insomnia.

    PubMed

    Sedigh, Golnaz; Devlin, Rose Anne; Grenier, Gilles; Deri Armstrong, Catherine

    2017-02-01

    This paper uses the 2005 and 2010 Canadian General Social Surveys (Time Use) to investigate the effect of wages on the sleep duration of individuals in the labour force. The endogeneity of wages is taken into account with an instrumental variables approach; we find that the wage rate affects sleeping time in general, corroborating Biddle and Hamermesh's (1990) main conclusion. A ten percent increase in the wage rate leads to an 11-12min decrease in sleep per week. But this number masks several effects. The responsiveness of sleep time to wage rate changes depends upon the sex of the individual, whether or not sleep problems are present and general economic conditions. By far the largest adjustment is found for insomniacs in 2010, a year of general economic downturn in Canada. We also investigate the non-randomness of insomnia in the population by using a Heckman procedure, and find that the sleep time of female non-insomniacs is even more responsive to wage rate changes once account is taken of this selection bias, but otherwise selection was not a problem in our samples. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  5. Mixing rates and limit theorems for random intermittent maps

    NASA Astrophysics Data System (ADS)

    Bahsoun, Wael; Bose, Christopher

    2016-04-01

    We study random transformations built from intermittent maps on the unit interval that share a common neutral fixed point. We focus mainly on random selections of Pomeu-Manneville-type maps {{T}α} using the full parameter range 0<α <∞ , in general. We derive a number of results around a common theme that illustrates in detail how the constituent map that is fastest mixing (i.e. smallest α) combined with details of the randomizing process, determines the asymptotic properties of the random transformation. Our key result (theorem 1.1) establishes sharp estimates on the position of return time intervals for the quenched dynamics. The main applications of this estimate are to limit laws (in particular, CLT and stable laws, depending on the parameters chosen in the range 0<α <1 ) for the associated skew product; these are detailed in theorem 3.2. Since our estimates in theorem 1.1 also hold for 1≤slant α <∞ we study a second class of random transformations derived from piecewise affine Gaspard-Wang maps, prove existence of an infinite (σ-finite) invariant measure and study the corresponding correlation asymptotics. To the best of our knowledge, this latter kind of result is completely new in the setting of random transformations.

  6. Prevalence and occupational associations of neck pain in the British population.

    PubMed

    Palmer, K T; Walker-Bone, K; Griffin, M J; Syddall, H; Pannett, B; Coggon, D; Cooper, C

    2001-02-01

    This study determined the prevalence of neck pain and its relation to occupation and occupational activities in the general population. A questionnaire was mailed to 21 201 subjects aged 16-64 years, randomly selected from the patient registers of general practices in England, Scotland, and Wales, and to 993 subjects randomly selected from pay records of the armed services. Information was collected on occupation, workplace physical activities, neck pain in the past week and year, headaches, and feelings of tiredness or stress. Associations were explored by logistic regression, the resultant odds ratios being converted to prevalence ratios (PR). Among 12907 respondents, 4348 and 2528 reported neck pain in past year (1421 with pain interfering with normal activities) and week, respectively. Symptoms were the most prevalent among male construction workers [past week and year 24% and 38% (pain interfering with activities 11%), respectively], followed by nurses, armed services members, and the unemployed. Generally the age-standardized prevalence of neck pain varied little by occupation. Work with arms above the shoulders for >1 hours/day was associated with a significant excess of symptoms [PR 1.3-1.7 (women) and 1.2-1.4 (men)], but no associations existed for typing, lifting, vibratory tool use, or professional driving. Stronger neck-pain associations were found with frequent headaches (PR 2.3-2.8) and frequent tiredness or stress (PR 2.2-2.5) than with occupational activities. The data provide evidence against a strong association between neck pain and the examined occupational physical activities. They suggest that psychosocial factors may be more important.

  7. Urban public attitudes to the treatment of psychological problems and depression in general practice.

    PubMed

    Gavigan, P; Carr, A; McKeon, P

    2000-10-01

    A previous national study of public attitudes to depression indicated that only 17% spontaneously mentioned their general practitioner as someone who could help with depression, in contrast to 79% of respondents being willing to consult their G.P. in a similar U.K. survey. The present study undertook to examine the public perception of an urban sample to the treatment of depression in general practice and the factors associated with expressed unwillingness to consult. A random sample from the electoral register was drawn and 54 (89%) of 61 subjects selected were interviewed. While 85% of respondents were satisfied with their general practice care, only 24% to 52%, depending on the context and wording of the question, said that they would seek help from their general practitioner for depression. Factors associated with an expressed reluctance to consult were being male, dissatisfied with general practitioner care and believing that general practitioners were not qualified to treat depression.

  8. Prevalence of atrial fibrillation in Spain. OFRECE study results.

    PubMed

    Gómez-Doblas, Juan José; Muñiz, Javier; Martin, Joaquín J Alonso; Rodríguez-Roca, Gustavo; Lobos, José Maria; Awamleh, Paula; Permanyer-Miralda, Gaietá; Chorro, Francisco Javier; Anguita, Manuel; Roig, Eulalia

    2014-04-01

    Atrial fibrillation is associated with substantial morbidity and mortality and both its incidence and prevalence are high. Nevertheless, comprehensive data on this condition in Spain are lacking. The aim of this study was to estimate the prevalence of atrial fibrillation in Spain. A cross-sectional study was conducted in the general Spanish population older than 40 years. Two-stage random sampling was used, in which first-stage units were primary care physicians randomly selected in every Spanish province and second-stage units were 20 randomly selected persons drawn from each participating physician's assigned population. The reported prevalence was standardized for the age and sex distribution of the Spanish population. The electrocardiogram recordings were read centrally. Overall, 8343 individuals were evaluated. The mean age was 59.2 years (95% confidence interval, 58.6-59.8 years), and 52.4% of the participants were female. The overall age-adjusted prevalence of atrial fibrillation was 4.4% (95% confidence interval, 3.8-5.1). Prevalence was similar in both sexes, men 4.4% (3.6-5.2) and women 4.5% (3.6-5.3), rising with increasing age older than 60 years. In patients older than 80 years, the prevalence was 17.7% (14.1-21.3). In 10% of patients an unknown atrial fibrillation was diagnosed. The prevalence of atrial fibrillation in the general Spanish population older than 40 years is high, at 4.4%. The prevalence is similar in both sexes and rises steeply above 60 years of age. It is estimated that there are over 1 million patients with atrial fibrillation in the Spanish population, of whom over 90,000 are undiagnosed. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  9. Disease Surveillance on Complex Social Networks

    PubMed Central

    Herrera, Jose L.; Srinivasan, Ravi; Brownstein, John S.; Galvani, Alison P.; Meyers, Lauren Ancel

    2016-01-01

    As infectious disease surveillance systems expand to include digital, crowd-sourced, and social network data, public health agencies are gaining unprecedented access to high-resolution data and have an opportunity to selectively monitor informative individuals. Contact networks, which are the webs of interaction through which diseases spread, determine whether and when individuals become infected, and thus who might serve as early and accurate surveillance sensors. Here, we evaluate three strategies for selecting sensors—sampling the most connected, random, and friends of random individuals—in three complex social networks—a simple scale-free network, an empirical Venezuelan college student network, and an empirical Montreal wireless hotspot usage network. Across five different surveillance goals—early and accurate detection of epidemic emergence and peak, and general situational awareness—we find that the optimal choice of sensors depends on the public health goal, the underlying network and the reproduction number of the disease (R0). For diseases with a low R0, the most connected individuals provide the earliest and most accurate information about both the onset and peak of an outbreak. However, identifying network hubs is often impractical, and they can be misleading if monitored for general situational awareness, if the underlying network has significant community structure, or if R0 is high or unknown. Taking a theoretical approach, we also derive the optimal surveillance system for early outbreak detection but find that real-world identification of such sensors would be nearly impossible. By contrast, the friends-of-random strategy offers a more practical and robust alternative. It can be readily implemented without prior knowledge of the network, and by identifying sensors with higher than average, but not the highest, epidemiological risk, it provides reasonably early and accurate information. PMID:27415615

  10. Disease Surveillance on Complex Social Networks.

    PubMed

    Herrera, Jose L; Srinivasan, Ravi; Brownstein, John S; Galvani, Alison P; Meyers, Lauren Ancel

    2016-07-01

    As infectious disease surveillance systems expand to include digital, crowd-sourced, and social network data, public health agencies are gaining unprecedented access to high-resolution data and have an opportunity to selectively monitor informative individuals. Contact networks, which are the webs of interaction through which diseases spread, determine whether and when individuals become infected, and thus who might serve as early and accurate surveillance sensors. Here, we evaluate three strategies for selecting sensors-sampling the most connected, random, and friends of random individuals-in three complex social networks-a simple scale-free network, an empirical Venezuelan college student network, and an empirical Montreal wireless hotspot usage network. Across five different surveillance goals-early and accurate detection of epidemic emergence and peak, and general situational awareness-we find that the optimal choice of sensors depends on the public health goal, the underlying network and the reproduction number of the disease (R0). For diseases with a low R0, the most connected individuals provide the earliest and most accurate information about both the onset and peak of an outbreak. However, identifying network hubs is often impractical, and they can be misleading if monitored for general situational awareness, if the underlying network has significant community structure, or if R0 is high or unknown. Taking a theoretical approach, we also derive the optimal surveillance system for early outbreak detection but find that real-world identification of such sensors would be nearly impossible. By contrast, the friends-of-random strategy offers a more practical and robust alternative. It can be readily implemented without prior knowledge of the network, and by identifying sensors with higher than average, but not the highest, epidemiological risk, it provides reasonably early and accurate information.

  11. Generalized Poisson-Kac Processes: Basic Properties and Implications in Extended Thermodynamics and Transport

    NASA Astrophysics Data System (ADS)

    Giona, Massimiliano; Brasiello, Antonio; Crescitelli, Silvestro

    2016-04-01

    We introduce a new class of stochastic processes in Rn,{{{mathbb R}}^n}, referred to as generalized Poisson-Kac (GPK) processes, that generalizes the Poisson-Kac telegrapher's random motion in higher dimensions. These stochastic processes possess finite propagation velocity, almost everywhere smooth trajectories, and converge in the Kac limit to Brownian motion. GPK processes are defined by coupling the selection of a bounded velocity vector from a family of N distinct ones with a Markovian dynamics controlling probabilistically this selection. This model can be used as a probabilistic tool for a stochastically consistent formulation of extended thermodynamic theories far from equilibrium.

  12. Improving Classification Performance through an Advanced Ensemble Based Heterogeneous Extreme Learning Machines.

    PubMed

    Abuassba, Adnan O M; Zhang, Dezheng; Luo, Xiong; Shaheryar, Ahmad; Ali, Hazrat

    2017-01-01

    Extreme Learning Machine (ELM) is a fast-learning algorithm for a single-hidden layer feedforward neural network (SLFN). It often has good generalization performance. However, there are chances that it might overfit the training data due to having more hidden nodes than needed. To address the generalization performance, we use a heterogeneous ensemble approach. We propose an Advanced ELM Ensemble (AELME) for classification, which includes Regularized-ELM, L 2 -norm-optimized ELM (ELML2), and Kernel-ELM. The ensemble is constructed by training a randomly chosen ELM classifier on a subset of training data selected through random resampling. The proposed AELM-Ensemble is evolved by employing an objective function of increasing diversity and accuracy among the final ensemble. Finally, the class label of unseen data is predicted using majority vote approach. Splitting the training data into subsets and incorporation of heterogeneous ELM classifiers result in higher prediction accuracy, better generalization, and a lower number of base classifiers, as compared to other models (Adaboost, Bagging, Dynamic ELM ensemble, data splitting ELM ensemble, and ELM ensemble). The validity of AELME is confirmed through classification on several real-world benchmark datasets.

  13. Improving Classification Performance through an Advanced Ensemble Based Heterogeneous Extreme Learning Machines

    PubMed Central

    Abuassba, Adnan O. M.; Ali, Hazrat

    2017-01-01

    Extreme Learning Machine (ELM) is a fast-learning algorithm for a single-hidden layer feedforward neural network (SLFN). It often has good generalization performance. However, there are chances that it might overfit the training data due to having more hidden nodes than needed. To address the generalization performance, we use a heterogeneous ensemble approach. We propose an Advanced ELM Ensemble (AELME) for classification, which includes Regularized-ELM, L2-norm-optimized ELM (ELML2), and Kernel-ELM. The ensemble is constructed by training a randomly chosen ELM classifier on a subset of training data selected through random resampling. The proposed AELM-Ensemble is evolved by employing an objective function of increasing diversity and accuracy among the final ensemble. Finally, the class label of unseen data is predicted using majority vote approach. Splitting the training data into subsets and incorporation of heterogeneous ELM classifiers result in higher prediction accuracy, better generalization, and a lower number of base classifiers, as compared to other models (Adaboost, Bagging, Dynamic ELM ensemble, data splitting ELM ensemble, and ELM ensemble). The validity of AELME is confirmed through classification on several real-world benchmark datasets. PMID:28546808

  14. Systematic instruction for individuals with acquired brain injury: Results of a randomized controlled trial

    PubMed Central

    Powell, Laurie Ehlhardt; Glang, Ann; Ettel, Deborah; Todis, Bonnie; Sohlberg, McKay; Albin, Richard

    2012-01-01

    The goal of this study was to experimentally evaluate systematic instruction compared with trial-and-error learning (conventional instruction) applied to assistive technology for cognition (ATC), in a double blind, pretest-posttest, randomized controlled trial. Twenty-nine persons with moderate-severe cognitive impairments due to acquired brain injury (15 in systematic instruction group; 14 in conventional instruction) completed the study. Both groups received 12, 45-minute individual training sessions targeting selected skills on the Palm Tungsten E2 personal digital assistant (PDA). A criterion-based assessment of PDA skills was used to evaluate accuracy, fluency/efficiency, maintenance, and generalization of skills. There were no significant differences between groups at immediate posttest with regard to accuracy and fluency. However, significant differences emerged at 30-day follow-up in favor of systematic instruction. Furthermore, systematic instruction participants performed significantly better at immediate posttest generalizing trained PDA skills when interacting with people other than the instructor. These results demonstrate that systematic instruction applied to ATC results in better skill maintenance and generalization than trial-and-error learning for individuals with moderate-severe cognitive impairments due to acquired brain injury. Implications, study limitations, and directions for future research are discussed. PMID:22264146

  15. Simulation of 'hitch-hiking' genealogies.

    PubMed

    Slade, P F

    2001-01-01

    An ancestral influence graph is derived, an analogue of the coalescent and a composite of Griffiths' (1991) two-locus ancestral graph and Krone and Neuhauser's (1997) ancestral selection graph. This generalizes their use of branching-coalescing random graphs so as to incorporate both selection and recombination into gene genealogies. Qualitative understanding of a 'hitch-hiking' effect on genealogies is pursued via diagrammatic representation of the genealogical process in a two-locus, two-allele haploid model. Extending the simulation technique of Griffiths and Tavare (1996), computational estimation of expected times to the most recent common ancestor of samples of n genes under recombination and selection in two-locus, two-allele haploid and diploid models are presented. Such times are conditional on sample configuration. Monte Carlo simulations show that 'hitch-hiking' is a subtle effect that alters the conditional expected depth of the genealogy at the linked neutral locus depending on a mutation-selection-recombination balance.

  16. Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study.

    PubMed

    Higdon, Melissa M; Hammitt, Laura L; Deloria Knoll, Maria; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Madhi, Shabir A; Murdoch, David R; Scott, J Anthony G; Thea, Donald M; Driscoll, Amanda J; Karron, Ruth A; Park, Daniel E; Prosperi, Christine; Zeger, Scott L; O'Brien, Katherine L; Feikin, Daniel R

    2017-06-15

    Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  17. The Evaluation of Bivariate Mixed Models in Meta-analyses of Diagnostic Accuracy Studies with SAS, Stata and R.

    PubMed

    Vogelgesang, Felicitas; Schlattmann, Peter; Dewey, Marc

    2018-05-01

    Meta-analyses require a thoroughly planned procedure to obtain unbiased overall estimates. From a statistical point of view not only model selection but also model implementation in the software affects the results. The present simulation study investigates the accuracy of different implementations of general and generalized bivariate mixed models in SAS (using proc mixed, proc glimmix and proc nlmixed), Stata (using gllamm, xtmelogit and midas) and R (using reitsma from package mada and glmer from package lme4). Both models incorporate the relationship between sensitivity and specificity - the two outcomes of interest in meta-analyses of diagnostic accuracy studies - utilizing random effects. Model performance is compared in nine meta-analytic scenarios reflecting the combination of three sizes for meta-analyses (89, 30 and 10 studies) with three pairs of sensitivity/specificity values (97%/87%; 85%/75%; 90%/93%). The evaluation of accuracy in terms of bias, standard error and mean squared error reveals that all implementations of the generalized bivariate model calculate sensitivity and specificity estimates with deviations less than two percentage points. proc mixed which together with reitsma implements the general bivariate mixed model proposed by Reitsma rather shows convergence problems. The random effect parameters are in general underestimated. This study shows that flexibility and simplicity of model specification together with convergence robustness should influence implementation recommendations, as the accuracy in terms of bias was acceptable in all implementations using the generalized approach. Schattauer GmbH.

  18. VARIABLE SELECTION FOR REGRESSION MODELS WITH MISSING DATA

    PubMed Central

    Garcia, Ramon I.; Ibrahim, Joseph G.; Zhu, Hongtu

    2009-01-01

    We consider the variable selection problem for a class of statistical models with missing data, including missing covariate and/or response data. We investigate the smoothly clipped absolute deviation penalty (SCAD) and adaptive LASSO and propose a unified model selection and estimation procedure for use in the presence of missing data. We develop a computationally attractive algorithm for simultaneously optimizing the penalized likelihood function and estimating the penalty parameters. Particularly, we propose to use a model selection criterion, called the ICQ statistic, for selecting the penalty parameters. We show that the variable selection procedure based on ICQ automatically and consistently selects the important covariates and leads to efficient estimates with oracle properties. The methodology is very general and can be applied to numerous situations involving missing data, from covariates missing at random in arbitrary regression models to nonignorably missing longitudinal responses and/or covariates. Simulations are given to demonstrate the methodology and examine the finite sample performance of the variable selection procedures. Melanoma data from a cancer clinical trial is presented to illustrate the proposed methodology. PMID:20336190

  19. The Dental Needs of Reserve Component Soldiers. Volume 1. Introduction, Methods, and Characteristics of Study Sample

    DTIC Science & Technology

    1992-11-01

    each soldier, we selected one side of the mouth at random and examined all teeth on that side, except third molars . The rationale and measurement...any third molars that had at least one of the following signs or symptoms: suppuration, swelling, or pain. Because acute necrotizing ulcerative...explanatory. DMFS DETERMINATION GENERAL INSTRUCTIONS For the DMFS assessment, examine all teeth, excluding third molars . Make an entry for every tooth on

  20. Developing a reliable and valid instrument to assess health-affecting aspects of neighborhoods in Tehran

    PubMed Central

    Ghalichi, Leila; Mohammad, Kazem; Majdzadeh, Reza; Hoseini, Mostafa; Pournik, Omid; Nedjat, Saharnaz

    2012-01-01

    Background: Residence characteristics can affect health of residents. This paper reports the development of an instrument assessing these aspects of neighborhoods. Materials and Methods: Literature search and focus group discussions with residents were carried out and relevant items were extracted. Five experts reviewed and commented on the items. An observation instrument with 54 items was composed and completed by two independent observers in 20 randomly selected locations. Due to lack of acceptable reliability in some items, the checklist was revised. The new 22-items checklist in four categories (general characteristics, public green area characteristics, access to services and undesirable features) was completed by two independent trained observers in 28 randomly selected locations. Results: The items in the final checklist had kappa statistics ranging from 0.63 to 1, with an exception of the item assessing “presence of beggars, homeless or working/street children”, with kappa as low as 0.27 due to variability of their presence in different times. Average Kappa statistics was 0.78 for general characteristics, 0.79 for public green area characteristics, 0.84 for access to services, and 0.54 for undesirable features. Conclusion: Neighborhood and health observation instrument seems to have good reliability in city of Tehran. It can probably be used in other large cities of Iran and similar cities elsewhere. PMID:23626633

  1. What affects response rates in primary healthcare-based programmes? An analysis of individual and unit-related factors associated with increased odds of non-response based on HCV screening in the general population in Poland

    PubMed Central

    Parda, Natalia; Stępień, Małgorzata; Zakrzewska, Karolina; Madaliński, Kazimierz; Kołakowska, Agnieszka; Godzik, Paulina; Rosińska, Magdalena

    2016-01-01

    Objectives Response rate in public health programmes may be a limiting factor. It is important to first consider their delivery and acceptability for the target. This study aimed at determining individual and unit-related factors associated with increased odds of non-response based on hepatitis C virus screening in primary healthcare. Design Primary healthcare units (PHCUs) were extracted from the Register of Health Care Centres. Each of the PHCUs was to enrol adult patients selected on a random basis. Data on the recruitment of PHCUs and patients were analysed. Multilevel modelling was applied to investigate individual and unit-related factors associated with non-response. Multilevel logistic model was developed with fixed effects and only a random intercept for the unit. Preliminary analysis included a random effect for unit and each of the individual or PHCU covariates separately. For each of the PHCU covariates, we applied a two-level model with individual covariates, unit random effect and a single fixed effect of this unit covariate. Setting This study was conducted in primary care units in selected provinces in Poland. Participants A total of 242 PHCUs and 24 480 adults were invited. Of them, 44 PHCUs and 20 939 patients agreed to participate. Both PHCUs and patients were randomly selected. Results Data on 44 PHCUs and 24 480 patients were analysed. PHCU-level factors and recruitment strategies were important predictors of non-response. Unit random effect was significant in all models. Larger and private units reported higher non-response rates, while for those with a history of running public health programmes the odds of non-response was lower. Proactive recruitment, more working hours devoted to the project and patient resulted in higher acceptance of the project. Higher number of personnel had no such effect. Conclusions Prior to the implementation of public health programme, several factors that could hinder its execution should be addressed. PMID:27927665

  2. What affects response rates in primary healthcare-based programmes? An analysis of individual and unit-related factors associated with increased odds of non-response based on HCV screening in the general population in Poland.

    PubMed

    Parda, Natalia; Stępień, Małgorzata; Zakrzewska, Karolina; Madaliński, Kazimierz; Kołakowska, Agnieszka; Godzik, Paulina; Rosińska, Magdalena

    2016-12-07

    Response rate in public health programmes may be a limiting factor. It is important to first consider their delivery and acceptability for the target. This study aimed at determining individual and unit-related factors associated with increased odds of non-response based on hepatitis C virus screening in primary healthcare. Primary healthcare units (PHCUs) were extracted from the Register of Health Care Centres. Each of the PHCUs was to enrol adult patients selected on a random basis. Data on the recruitment of PHCUs and patients were analysed. Multilevel modelling was applied to investigate individual and unit-related factors associated with non-response. Multilevel logistic model was developed with fixed effects and only a random intercept for the unit. Preliminary analysis included a random effect for unit and each of the individual or PHCU covariates separately. For each of the PHCU covariates, we applied a two-level model with individual covariates, unit random effect and a single fixed effect of this unit covariate. This study was conducted in primary care units in selected provinces in Poland. A total of 242 PHCUs and 24 480 adults were invited. Of them, 44 PHCUs and 20 939 patients agreed to participate. Both PHCUs and patients were randomly selected. Data on 44 PHCUs and 24 480 patients were analysed. PHCU-level factors and recruitment strategies were important predictors of non-response. Unit random effect was significant in all models. Larger and private units reported higher non-response rates, while for those with a history of running public health programmes the odds of non-response was lower. Proactive recruitment, more working hours devoted to the project and patient resulted in higher acceptance of the project. Higher number of personnel had no such effect. Prior to the implementation of public health programme, several factors that could hinder its execution should be addressed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. Response rate differences between web and alternative data collection methods for public health research: a systematic review of the literature.

    PubMed

    Blumenberg, Cauane; Barros, Aluísio J D

    2018-07-01

    To systematically review the literature and compare response rates (RRs) of web surveys to alternative data collection methods in the context of epidemiologic and public health studies. We reviewed the literature using PubMed, LILACS, SciELO, WebSM, and Google Scholar databases. We selected epidemiologic and public health studies that considered the general population and used two parallel data collection methods, being one web-based. RR differences were analyzed using two-sample test of proportions, and pooled using random effects. We investigated agreement using Bland-and-Altman, and correlation using Pearson's coefficient. We selected 19 studies (nine randomized trials). The RR of the web-based data collection was 12.9 percentage points (p.p.) lower (95% CI = - 19.0, - 6.8) than the alternative methods, and 15.7 p.p. lower (95% CI = - 24.2, - 7.3) considering only randomized trials. Monetary incentives did not reduce the RR differences. A strong positive correlation (r = 0.83) between the RRs was observed. Web-based data collection present lower RRs compared to alternative methods. However, it is not recommended to interpret this as a meta-analytical evidence due to the high heterogeneity of the studies.

  4. Changes in Attitudes Towards Bariatric Surgery After 5 Years in the German General Public.

    PubMed

    Jung, Franziska Ulrike Christine Else; Dietrich, A; Stroh, C; Riedel-Heller, S G; Luck-Sikorski, C

    2017-10-01

    The aim of this study was to investigate changes in attitudes of the general public towards bariatric surgery and other interventions that can be part of obesity management, during the last 5 years. 1007 participants were randomly selected and interviewed. Apart from socio-demographic data, interviews also included causal reasons for obesity as well as questions regarding treatment methods and their believed effectiveness. Results were compared with data published 5 years ago. Surgery is seen as a rather ineffective method to reduce weight in obesity and is recommended less often by the general public compared to the assessment 5 years ago. Public health-implications should inform about obesity and benefits of surgery as an intervention to improve individual health conditions.

  5. Factors Associated With Time to Site Activation, Randomization, and Enrollment Performance in a Stroke Prevention Trial.

    PubMed

    Demaerschalk, Bart M; Brown, Robert D; Roubin, Gary S; Howard, Virginia J; Cesko, Eldina; Barrett, Kevin M; Longbottom, Mary E; Voeks, Jenifer H; Chaturvedi, Seemant; Brott, Thomas G; Lal, Brajesh K; Meschia, James F; Howard, George

    2017-09-01

    Multicenter clinical trials attempt to select sites that can move rapidly to randomization and enroll sufficient numbers of patients. However, there are few assessments of the success of site selection. In the CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trials), we assess factors associated with the time between site selection and authorization to randomize, the time between authorization to randomize and the first randomization, and the average number of randomizations per site per month. Potential factors included characteristics of the site, specialty of the principal investigator, and site type. For 147 sites, the median time between site selection to authorization to randomize was 9.9 months (interquartile range, 7.7, 12.4), and factors associated with early site activation were not identified. The median time between authorization to randomize and a randomization was 4.6 months (interquartile range, 2.6, 10.5). Sites with authorization to randomize in only the carotid endarterectomy study were slower to randomize, and other factors examined were not significantly associated with time-to-randomization. The recruitment rate was 0.26 (95% confidence interval, 0.23-0.28) patients per site per month. By univariate analysis, factors associated with faster recruitment were authorization to randomize in both trials, principal investigator specialties of interventional radiology and cardiology, pre-trial reported performance >50 carotid angioplasty and stenting procedures per year, status in the top half of recruitment in the CREST trial, and classification as a private health facility. Participation in StrokeNet was associated with slower recruitment as compared with the non-StrokeNet sites. Overall, selection of sites with high enrollment rates will likely require customization to align the sites selected to the factor under study in the trial. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02089217. © 2017 American Heart Association, Inc.

  6. Ordinal judgments of numerical symbols by macaques (Macaca mulatta)

    NASA Technical Reports Server (NTRS)

    Washburn, David A.; Rumbaugh, Duane M.

    1991-01-01

    Two rhesus monkeys (Macaca mulatta) learned that the arabic numerals 0 through 9 represented corresponding quantities of food pellets. By manipulating a joystick, the monkeys were able to make a selection of paired numerals presented on a computer screen. Although the monkeys received a corresponding number of pellets even if the lesser of the two numerals was selected, they learned generally to choose the numeral of greatest value even when pellet delivery was made arrhythmic. In subsequent tests, they chose the numerals of greater value when presented in novel combinations or in random arrays of up to five numerals. Thus, the monkeys made ordinal judgments of numerical symbols in accordance with their absolute or relative values.

  7. The distribution of genetic variance across phenotypic space and the response to selection.

    PubMed

    Blows, Mark W; McGuigan, Katrina

    2015-05-01

    The role of adaptation in biological invasions will depend on the availability of genetic variation for traits under selection in the new environment. Although genetic variation is present for most traits in most populations, selection is expected to act on combinations of traits, not individual traits in isolation. The distribution of genetic variance across trait combinations can be characterized by the empirical spectral distribution of the genetic variance-covariance (G) matrix. Empirical spectral distributions of G from a range of trait types and taxa all exhibit a characteristic shape; some trait combinations have large levels of genetic variance, while others have very little genetic variance. In this study, we review what is known about the empirical spectral distribution of G and show how it predicts the response to selection across phenotypic space. In particular, trait combinations that form a nearly null genetic subspace with little genetic variance respond only inconsistently to selection. We go on to set out a framework for understanding how the empirical spectral distribution of G may differ from the random expectations that have been developed under random matrix theory (RMT). Using a data set containing a large number of gene expression traits, we illustrate how hypotheses concerning the distribution of multivariate genetic variance can be tested using RMT methods. We suggest that the relative alignment between novel selection pressures during invasion and the nearly null genetic subspace is likely to be an important component of the success or failure of invasion, and for the likelihood of rapid adaptation in small populations in general. © 2014 John Wiley & Sons Ltd.

  8. Not accounting for interindividual variability can mask habitat selection patterns: a case study on black bears.

    PubMed

    Lesmerises, Rémi; St-Laurent, Martin-Hugues

    2017-11-01

    Habitat selection studies conducted at the population scale commonly aim to describe general patterns that could improve our understanding of the limiting factors in species-habitat relationships. Researchers often consider interindividual variation in selection patterns to control for its effects and avoid pseudoreplication by using mixed-effect models that include individuals as random factors. Here, we highlight common pitfalls and possible misinterpretations of this strategy by describing habitat selection of 21 black bears Ursus americanus. We used Bayesian mixed-effect models and compared results obtained when using random intercept (i.e., population level) versus calculating individual coefficients for each independent variable (i.e., individual level). We then related interindividual variability to individual characteristics (i.e., age, sex, reproductive status, body condition) in a multivariate analysis. The assumption of comparable behavior among individuals was verified only in 40% of the cases in our seasonal best models. Indeed, we found strong and opposite responses among sampled bears and individual coefficients were linked to individual characteristics. For some covariates, contrasted responses canceled each other out at the population level. In other cases, interindividual variability was concealed by the composition of our sample, with the majority of the bears (e.g., old individuals and bears in good physical condition) driving the population response (e.g., selection of young forest cuts). Our results stress the need to consider interindividual variability to avoid misinterpretation and uninformative results, especially for a flexible and opportunistic species. This study helps to identify some ecological drivers of interindividual variability in bear habitat selection patterns.

  9. Optimal source coding, removable noise elimination, and natural coordinate system construction for general vector sources using replicator neural networks

    NASA Astrophysics Data System (ADS)

    Hecht-Nielsen, Robert

    1997-04-01

    A new universal one-chart smooth manifold model for vector information sources is introduced. Natural coordinates (a particular type of chart) for such data manifolds are then defined. Uniformly quantized natural coordinates form an optimal vector quantization code for a general vector source. Replicator neural networks (a specialized type of multilayer perceptron with three hidden layers) are the introduced. As properly configured examples of replicator networks approach minimum mean squared error (e.g., via training and architecture adjustment using randomly chosen vectors from the source), these networks automatically develop a mapping which, in the limit, produces natural coordinates for arbitrary source vectors. The new concept of removable noise (a noise model applicable to a wide variety of real-world noise processes) is then discussed. Replicator neural networks, when configured to approach minimum mean squared reconstruction error (e.g., via training and architecture adjustment on randomly chosen examples from a vector source, each with randomly chosen additive removable noise contamination), in the limit eliminate removable noise and produce natural coordinates for the data vector portions of the noise-corrupted source vectors. Consideration regarding selection of the dimension of a data manifold source model and the training/configuration of replicator neural networks are discussed.

  10. Optimal timing in biological processes

    USGS Publications Warehouse

    Williams, B.K.; Nichols, J.D.

    1984-01-01

    A general approach for obtaining solutions to a class of biological optimization problems is provided. The general problem is one of determining the appropriate time to take some action, when the action can be taken only once during some finite time frame. The approach can also be extended to cover a number of other problems involving animal choice (e.g., mate selection, habitat selection). Returns (assumed to index fitness) are treated as random variables with time-specific distributions, and can be either observable or unobservable at the time action is taken. In the case of unobservable returns, the organism is assumed to base decisions on some ancillary variable that is associated with returns. Optimal policies are derived for both situations and their properties are discussed. Various extensions are also considered, including objective functions based on functions of returns other than the mean, nonmonotonic relationships between the observable variable and returns; possible death of the organism before action is taken; and discounting of future returns. A general feature of the optimal solutions for many of these problems is that an organism should be very selective (i.e., should act only when returns or expected returns are relatively high) at the beginning of the time frame and should become less and less selective as time progresses. An example of the application of optimal timing to a problem involving the timing of bird migration is discussed, and a number of other examples for which the approach is applicable are described.

  11. In Vitro Selection of pH-Activated DNA Nanostructures.

    PubMed

    Fong, Faye Yi; Oh, Seung Soo; Hawker, Craig J; Soh, H Tom

    2016-12-05

    We report the first in vitro selection of DNA nanostructures that switch their conformation when triggered by change in pH. Previously, most pH-active nanostructures were designed using known pH-active motifs, such as the i-motif or the triplex structure. In contrast, we performed de novo selections starting from a random library and generated nanostructures that can sequester and release Mipomersen, a clinically approved antisense DNA drug, in response to pH change. We demonstrate extraordinary pH-selectivity, releasing up to 714-fold more Mipomersen at pH 5.2 compared to pH 7.5. Interestingly, none of our nanostructures showed significant sequence similarity to known pH-sensitive motifs, suggesting that they may operate via novel structure-switching mechanisms. We believe our selection scheme is general and could be adopted for generating DNA nanostructures for many applications including drug delivery, sensors and pH-active surfaces. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. [Natural selection associated with color vision defects in some population groups of Eurasia].

    PubMed

    Evsiukov, A N

    2014-01-01

    Fitness coefficients and other quantitative parameters of selection associated with the generalized color blindness gene CB+ were obtained for three ethnogeographic population groups, including Belarusians from Belarus, ethnic populations of the Volga-Ural region, and ethnic populations of Siberia and the Far East of Russia. All abnormalities encoded by the OPN1LW and OPN1MW loci were treated as deviations from normal color perception. Coefficients were estimated from an approximation of the observed CB+ frequency distributions to the theoretical stationary distribution for the Wright island model. This model takes into account the pressure of migrations, selection, and random genetic drift, while the selection parameters are represented in the form of the distribution parameters. In the populations of Siberia and Far East, directional selection in favor of normal color vision and the corresponding allele CB- was observed. In the Belarusian and ethnic populations of the Volga-Ural region, stabilizing selection was observed. The selection intensity constituted 0.03 in the Belarusian; 0.22 in the ethnic populations of the Volga-Ural region; and 0.24 in ethnic populations of Siberia and Far East.

  13. Microscopic Interpretation and Generalization of the Bloch-Torrey Equation for Diffusion Magnetic Resonance

    PubMed Central

    Seroussi, Inbar; Grebenkov, Denis S.; Pasternak, Ofer; Sochen, Nir

    2017-01-01

    In order to bridge microscopic molecular motion with macroscopic diffusion MR signal in complex structures, we propose a general stochastic model for molecular motion in a magnetic field. The Fokker-Planck equation of this model governs the probability density function describing the diffusion-magnetization propagator. From the propagator we derive a generalized version of the Bloch-Torrey equation and the relation to the random phase approach. This derivation does not require assumptions such as a spatially constant diffusion coefficient, or ad-hoc selection of a propagator. In particular, the boundary conditions that implicitly incorporate the microstructure into the diffusion MR signal can now be included explicitly through a spatially varying diffusion coefficient. While our generalization is reduced to the conventional Bloch-Torrey equation for piecewise constant diffusion coefficients, it also predicts scenarios in which an additional term to the equation is required to fully describe the MR signal. PMID:28242566

  14. Robustness of optimal random searches in fragmented environments

    NASA Astrophysics Data System (ADS)

    Wosniack, M. E.; Santos, M. C.; Raposo, E. P.; Viswanathan, G. M.; da Luz, M. G. E.

    2015-05-01

    The random search problem is a challenging and interdisciplinary topic of research in statistical physics. Realistic searches usually take place in nonuniform heterogeneous distributions of targets, e.g., patchy environments and fragmented habitats in ecological systems. Here we present a comprehensive numerical study of search efficiency in arbitrarily fragmented landscapes with unlimited visits to targets that can only be found within patches. We assume a random walker selecting uniformly distributed turning angles and step lengths from an inverse power-law tailed distribution with exponent μ . Our main finding is that for a large class of fragmented environments the optimal strategy corresponds approximately to the same value μopt≈2 . Moreover, this exponent is indistinguishable from the well-known exact optimal value μopt=2 for the low-density limit of homogeneously distributed revisitable targets. Surprisingly, the best search strategies do not depend (or depend only weakly) on the specific details of the fragmentation. Finally, we discuss the mechanisms behind this observed robustness and comment on the relevance of our results to both the random search theory in general, as well as specifically to the foraging problem in the biological context.

  15. Effect of electromagnetic radiations from mobile phone base stations on general health and salivary function.

    PubMed

    Singh, Kushpal; Nagaraj, Anup; Yousuf, Asif; Ganta, Shravani; Pareek, Sonia; Vishnani, Preeti

    2016-01-01

    Cell phones use electromagnetic, nonionizing radiations in the microwave range, which some believe may be harmful to human health. The present study aimed to determine the effect of electromagnetic radiations (EMRs) on unstimulated/stimulated salivary flow rate and other health-related problems between the general populations residing in proximity to and far away from mobile phone base stations. A total of four mobile base stations were randomly selected from four zones of Jaipur, Rajasthan, India. Twenty individuals who were residing in proximity to the selected mobile phone towers were taken as the case group and the other 20 individuals (control group) who were living nearly 1 km away in the periphery were selected for salivary analysis. Questions related to sleep disturbances were measured using Pittsburgh Sleep Quality Index (PSQI) and other health problems were included in the questionnaire. Chi-square test was used for statistical analysis. It was unveiled that a majority of the subjects who were residing near the mobile base station complained of sleep disturbances, headache, dizziness, irritability, concentration difficulties, and hypertension. A majority of the study subjects had significantly lesser stimulated salivary secretion (P < 0.01) as compared to the control subjects. The effects of prolonged exposure to EMRs from mobile phone base stations on the health and well-being of the general population cannot be ruled out. Further studies are warranted to evaluate the effect of electromagnetic fields (EMFs) on general health and more specifically on oral health.

  16. Randomized Controlled Trial of SuperBetter, a Smartphone-Based/Internet-Based Self-Help Tool to Reduce Depressive Symptoms.

    PubMed

    Roepke, Ann Marie; Jaffee, Sara R; Riffle, Olivia M; McGonigal, Jane; Broome, Rose; Maxwell, Bez

    2015-06-01

    Technological advances have sparked the development of computer- and smartphone-based self-help programs for depressed people, but these programs' efficacy is uncertain. This randomized controlled trial evaluated an intervention called SuperBetter (SB), which is accessed via smartphone and/or the SB Web site. Online, we recruited 283 adult iPhone(®) (Apple, Cupertino, CA) users with significant depression symptoms according to the Center for Epidemiological Studies Depression questionnaire (CES-D). They were randomly assigned to one of three conditions: (a) a version of SB using cognitive-behavioral therapy and positive psychotherapy strategies to target depression (CBT-PPT SB); (b) a general SB version focused on self-esteem and acceptance (General SB); or (c) a waiting list control group (WL). The two SB groups were instructed to use SB for 10 minutes daily for 1 month. All participants completed psychological distress and well-being measures online every 2 weeks through follow-up. An intent-to-treat analysis was conducted using hierarchical linear modeling. As hypothesized, SB participants achieved greater reductions in CES-D scores than WL participants by posttest (Cohen's d=0.67) and by follow-up (d=1.05). Contrary to prediction, CBT-PPT SB did not perform better than General SB; both versions of SB were more effective than the WL control. Differences between SB versions favored General SB but were not statistically significant. These large effect sizes should be interpreted cautiously in light of high attrition rates and the motivated, self-selected sample. Nonetheless, smartphone-based/Internet-based self-help may play an important role in treating depression.

  17. Marginal and Random Intercepts Models for Longitudinal Binary Data With Examples From Criminology.

    PubMed

    Long, Jeffrey D; Loeber, Rolf; Farrington, David P

    2009-01-01

    Two models for the analysis of longitudinal binary data are discussed: the marginal model and the random intercepts model. In contrast to the linear mixed model (LMM), the two models for binary data are not subsumed under a single hierarchical model. The marginal model provides group-level information whereas the random intercepts model provides individual-level information including information about heterogeneity of growth. It is shown how a type of numerical averaging can be used with the random intercepts model to obtain group-level information, thus approximating individual and marginal aspects of the LMM. The types of inferences associated with each model are illustrated with longitudinal criminal offending data based on N = 506 males followed over a 22-year period. Violent offending indexed by official records and self-report were analyzed, with the marginal model estimated using generalized estimating equations and the random intercepts model estimated using maximum likelihood. The results show that the numerical averaging based on the random intercepts can produce prediction curves almost identical to those obtained directly from the marginal model parameter estimates. The results provide a basis for contrasting the models and the estimation procedures and key features are discussed to aid in selecting a method for empirical analysis.

  18. Assessing Multivariate Constraints to Evolution across Ten Long-Term Avian Studies

    PubMed Central

    Teplitsky, Celine; Tarka, Maja; Møller, Anders P.; Nakagawa, Shinichi; Balbontín, Javier; Burke, Terry A.; Doutrelant, Claire; Gregoire, Arnaud; Hansson, Bengt; Hasselquist, Dennis; Gustafsson, Lars; de Lope, Florentino; Marzal, Alfonso; Mills, James A.; Wheelwright, Nathaniel T.; Yarrall, John W.; Charmantier, Anne

    2014-01-01

    Background In a rapidly changing world, it is of fundamental importance to understand processes constraining or facilitating adaptation through microevolution. As different traits of an organism covary, genetic correlations are expected to affect evolutionary trajectories. However, only limited empirical data are available. Methodology/Principal Findings We investigate the extent to which multivariate constraints affect the rate of adaptation, focusing on four morphological traits often shown to harbour large amounts of genetic variance and considered to be subject to limited evolutionary constraints. Our data set includes unique long-term data for seven bird species and a total of 10 populations. We estimate population-specific matrices of genetic correlations and multivariate selection coefficients to predict evolutionary responses to selection. Using Bayesian methods that facilitate the propagation of errors in estimates, we compare (1) the rate of adaptation based on predicted response to selection when including genetic correlations with predictions from models where these genetic correlations were set to zero and (2) the multivariate evolvability in the direction of current selection to the average evolvability in random directions of the phenotypic space. We show that genetic correlations on average decrease the predicted rate of adaptation by 28%. Multivariate evolvability in the direction of current selection was systematically lower than average evolvability in random directions of space. These significant reductions in the rate of adaptation and reduced evolvability were due to a general nonalignment of selection and genetic variance, notably orthogonality of directional selection with the size axis along which most (60%) of the genetic variance is found. Conclusions These results suggest that genetic correlations can impose significant constraints on the evolution of avian morphology in wild populations. This could have important impacts on evolutionary dynamics and hence population persistence in the face of rapid environmental change. PMID:24608111

  19. Universal Dimensions of Meaning Derived from Semantic Relations among Words and Senses: Mereological Completeness vs. Ontological Generality (Open Access, Publisher’s Version)

    DTIC Science & Technology

    2014-07-15

    Neurosci . 2013, doi:10.1155/2013/308176. 11. Goddard, C.; Wierzbicka, A. Semantics and cognition. Wiley Interdiscip. Rev.- Cogn . Sci. 2011, 2, 125–135...from the Journal of Neuroscience . Two article categories were selected for this analysis: 165 brief communications and 143 mini-reviews, randomly...valence, and arousal of two categories of recent articles from the Journal of Neuroscience : mini-reviews and brief communications (Figure 8). On average

  20. Permeability and selectivity of reverse osmosis membranes: correlation to swelling revisited.

    PubMed

    Dražević, Emil; Košutić, Krešimir; Freger, Viatcheslav

    2014-02-01

    Membrane swelling governs both rejection of solutes and permeability of polymeric membranes, however very few data have been available on swelling in water of salt-rejecting reverse osmosis (RO) membranes. This study assesses swelling, thickness and their relation to water permeability for four commercial polyamide (PA) RO membranes (SWC4+, ESPA1, XLE and BW30) using atomic force microscopy (AFM) and attenuated total reflection Fourier transform IR spectroscopy (ATR-FTIR). ATR-FTIR offered a significantly improved estimate of the actual barrier thickness of PA, given AFM is biased by porosity ("fluffy parts") or wiggling of the active layer or presence of a coating layer. Thus obtained intrinsic permeability (permeability times thickness) and selectivity of aromatic polyamides plotted versus swelling falls well on a general trend, along with previously reported data on several common materials showing RO and NF selectivity. The observed general trend may be rationalized by viewing the polymers as a random composite medium containing molecularly small pores. The results suggest that the combination of a rigid low dielectric matrix, limiting the pore size, with multiple hydrophilic H-bonding sites may be a common feature of RO/NF membranes, allowing both high permeability and selectivity. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  1. Mutation-selection equilibrium in games with mixed strategies.

    PubMed

    Tarnita, Corina E; Antal, Tibor; Nowak, Martin A

    2009-11-07

    We develop a new method for studying stochastic evolutionary game dynamics of mixed strategies. We consider the general situation: there are n pure strategies whose interactions are described by an nxn payoff matrix. Players can use mixed strategies, which are given by the vector (p(1),...,p(n)). Each entry specifies the probability to use the corresponding pure strategy. The sum over all entries is one. Therefore, a mixed strategy is a point in the simplex S(n). We study evolutionary dynamics in a well-mixed population of finite size. Individuals reproduce proportional to payoff. We consider the case of weak selection, which means the payoff from the game is only a small contribution to overall fitness. Reproduction can be subject to mutation; a mutant adopts a randomly chosen mixed strategy. We calculate the average abundance of every mixed strategy in the stationary distribution of the mutation-selection process. We find the crucial conditions that specify if a strategy is favored or opposed by selection. One condition holds for low mutation rate, another for high mutation rate. The result for any mutation rate is a linear combination of those two. As a specific example we study the Hawk-Dove game. We prove general statements about the relationship between games with pure and with mixed strategies.

  2. Fuzziness-based active learning framework to enhance hyperspectral image classification performance for discriminative and generative classifiers

    PubMed Central

    2018-01-01

    Hyperspectral image classification with a limited number of training samples without loss of accuracy is desirable, as collecting such data is often expensive and time-consuming. However, classifiers trained with limited samples usually end up with a large generalization error. To overcome the said problem, we propose a fuzziness-based active learning framework (FALF), in which we implement the idea of selecting optimal training samples to enhance generalization performance for two different kinds of classifiers, discriminative and generative (e.g. SVM and KNN). The optimal samples are selected by first estimating the boundary of each class and then calculating the fuzziness-based distance between each sample and the estimated class boundaries. Those samples that are at smaller distances from the boundaries and have higher fuzziness are chosen as target candidates for the training set. Through detailed experimentation on three publically available datasets, we showed that when trained with the proposed sample selection framework, both classifiers achieved higher classification accuracy and lower processing time with the small amount of training data as opposed to the case where the training samples were selected randomly. Our experiments demonstrate the effectiveness of our proposed method, which equates favorably with the state-of-the-art methods. PMID:29304512

  3. Obesity, Body Mass Index, and Homicide.

    PubMed

    Omond, Kimberley J; Langlois, Neil E I; Byard, Roger W

    2017-07-01

    The body mass indexes (BMIs) of 100 randomly selected homicide cases from the files of Forensic Science SA were compared to the Australian and South Australian populations. There were 70 males and 30 females (M:F = 2.3:1; age range 18-84 years; mean 42.3 years). There was a substantially lower proportion of obese individuals in the homicide population compared to the general Australian and South Australian populations (19% [vs.] 27.9% and 30%, respectively). A second group of 144 randomly selected autopsy cases where the BMI was ≥40 kg/m 2 was analyzed. There were 77 males and 67 females (M:F = 1.2:1; age range 23-78 years; mean 46.7 years). The majority of deaths were natural (N = 108), with no homicides. A negative association between obesity and homicide has, therefore, been demonstrated. Reasons for the lower numbers of obese/morbidly obese individuals among homicide victims are unclear, but may include physical protection afforded by fat padding from sharp force injuries, and relative sociodemographic isolation. © 2016 American Academy of Forensic Sciences.

  4. Prevalence and risk factors for Maedi-Visna in sheep farms in Mecklenburg-Western-Pomerania.

    PubMed

    Hüttner, Klim; Seelmann, Matthias; Feldhusen, Frerk

    2010-01-01

    Despite indications of a considerable spread of Maedi-Visna among sheep flocks in Germany, prevalence studies of this important infection are hardly available. Prior to any health schemes and guidelines, knowledge about regional disease distribution is essential. Depending upon herd size, 70 farms were randomly selected, of which 41 cooperated. A total of 2229 blood samples were taken at random and serologically examined. For assessment of selected farm characteristics a questionnaire exercise was conducted at all farms involved. The average herd prevalence is 51.2%, the within-herd prevalence is 28,8%. In the unvariate analysis of risk factors, small (10-100 sheep) and large (> 250 sheep) farms are more MVV-affected than medium sized farms. The average stable and pasture space per sheep is larger at non-infected- compared to infected farms. Owners judgement on general herd health turns out to be better at non-infected compared to infected farms. Taking infected farms only, the risk of within-herd prevalence above 20% is significant higher in crossbred than in purebred flocks.

  5. Demographics of Australian horse owners: results from an internet-based survey.

    PubMed

    Smyth, G B; Dagley, K

    2015-12-01

    To obtain information on the demographics of Australian horse owners. An invitation to participate in an opt-in, internet-based survey was sent to 7000 persons who had registered an email address to receive information from the Australian Horse Industry Council Inc. These horse owners represented approximately 1.75% of the total horse owners in Australia. The survey was available for completion between 1 and 31 July 2009. There were 3377 (48%) useable responses. The respondents were a self-selected group of approximately 0.85% of the estimated total horse owners in Australia. The overall geographic distribution of respondents was the same as the general population at a state and territory level. In general, respondents were female and aged between 31 and 60 years; most lived in rural areas of Queensland, New South Wales or Victoria; had at least a secondary education, but no formal horse industry qualification; had a higher weekly income if based in a capital city; earned less than 10% of weekly income from horse-related activities; were a member of more than one horse industry organisation; reported an affiliation with one of more than 300 different horse industry organisations; spent 10-30% of their daily time with horses; and preferred to receive information by email. The responses from this survey of horse owners provided demographic information that was previously unavailable. Horse owners tended to be older than the general population, had a higher level of education attainment, were in higher weekly income brackets and lived mostly in non-metropolitan areas of Australia. Because of the self-selection and small sample size, the results need to be interpreted with caution. Nevertheless, the present results are compatible with other smaller random and non-random surveys of horse owners internationally. © 2015 Australian Veterinary Association.

  6. An adaptive incremental approach to constructing ensemble classifiers: application in an information-theoretic computer-aided decision system for detection of masses in mammograms.

    PubMed

    Mazurowski, Maciej A; Zurada, Jacek M; Tourassi, Georgia D

    2009-07-01

    Ensemble classifiers have been shown efficient in multiple applications. In this article, the authors explore the effectiveness of ensemble classifiers in a case-based computer-aided diagnosis system for detection of masses in mammograms. They evaluate two general ways of constructing subclassifiers by resampling of the available development dataset: Random division and random selection. Furthermore, they discuss the problem of selecting the ensemble size and propose two adaptive incremental techniques that automatically select the size for the problem at hand. All the techniques are evaluated with respect to a previously proposed information-theoretic CAD system (IT-CAD). The experimental results show that the examined ensemble techniques provide a statistically significant improvement (AUC = 0.905 +/- 0.024) in performance as compared to the original IT-CAD system (AUC = 0.865 +/- 0.029). Some of the techniques allow for a notable reduction in the total number of examples stored in the case base (to 1.3% of the original size), which, in turn, results in lower storage requirements and a shorter response time of the system. Among the methods examined in this article, the two proposed adaptive techniques are by far the most effective for this purpose. Furthermore, the authors provide some discussion and guidance for choosing the ensemble parameters.

  7. Assessment of pharmaceutical waste management at selected hospitals and homes in Ghana.

    PubMed

    Sasu, Samuel; Kümmerer, Klaus; Kranert, Martin

    2012-06-01

    The practice of use and disposal of waste from pharmaceuticals compromises the safety of the environment as well as representing a serious health risk, as they may accumulate and stay active for a long time in the aquatic environment. This article therefore presents the outcome of a study on pharmaceutical waste management practices at homes and hospitals in Ghana. The study was conducted at five healthcare institutions randomly selected in Ghana, namely two teaching hospitals (hospital A, hospital B), one regional hospital (hospital C), one district hospital (hospital D) and one quasi-governmental hospital (hospital E). Apart from hospital E which currently has a pharmaceutical waste separation programmr as well as drug return programme called DUMP (Disposal of Unused Medicines Program), all other hospitals visited do not have any separate collection and disposal programme for pharmaceutical waste. A survey was also carried out among the general public, involving the questioning of randomly selected participants in order to investigate the household disposal of unused and expired pharmaceuticals. The results from the survey showed that more than half of the respondents confirmed having unused, left-over or expired medicines at home and over 75% disposed of pharmaceutical waste through the normal waste bins which end up in the landfills or dump sites.

  8. Amygdala Reactivity to Emotional Faces in the Prediction of General and Medication-Specific Responses to Antidepressant Treatment in the Randomized iSPOT-D Trial

    PubMed Central

    Williams, Leanne M; Korgaonkar, Mayuresh S; Song, Yun C; Paton, Rebecca; Eagles, Sarah; Goldstein-Piekarski, Andrea; Grieve, Stuart M; Harris, Anthony W F; Usherwood, Tim; Etkin, Amit

    2015-01-01

    Although the cost of poor treatment outcomes of depression is staggering, we do not yet have clinically useful methods for selecting the most effective antidepressant for each depressed person. Emotional brain activation is altered in major depressive disorder (MDD) and implicated in treatment response. Identifying which aspects of emotional brain activation are predictive of general and specific responses to antidepressants may help clinicians and patients when making treatment decisions. We examined whether amygdala activation probed by emotion stimuli is a general or differential predictor of response to three commonly prescribed antidepressants, using functional magnetic resonance imaging (fMRI). A test–retest design was used to assess patients with MDD in an academic setting as part of the International Study to Predict Optimized Treatment in Depression. A total of 80 MDD outpatients were scanned prior to treatment and 8 weeks after randomization to the selective serotonin reuptake inhibitors escitalopram and sertraline and the serotonin–norepinephrine reuptake inhibitor, venlafaxine-extended release (XR). A total of 34 matched controls were scanned at the same timepoints. We quantified the blood oxygen level-dependent signal of the amygdala during subliminal and supraliminal viewing of facial expressions of emotion. Response to treatment was defined by ⩾50% symptom improvement on the 17-item Hamilton Depression Rating Scale. Pre-treatment amygdala hypo-reactivity to subliminal happy and threat was a general predictor of treatment response, regardless of medication type (Cohen's d effect size 0.63 to 0.77; classification accuracy, 75%). Responders showed hypo-reactivity compared to controls at baseline, and an increase toward ‘normalization' post-treatment. Pre-treatment amygdala reactivity to subliminal sadness was a differential moderator of non-response to venlafaxine-XR (Cohen's d effect size 1.5; classification accuracy, 81%). Non-responders to venlafaxine-XR showed pre-treatment hyper-reactivity, which progressed to hypo-reactivity rather than normalization post-treatment, and hypo-reactivity post-treatment was abnormal compared to controls. Impaired amygdala activation has not previously been highlighted in the general vs differential prediction of antidepressant outcomes. Amygdala hypo-reactivity to emotions signaling reward and threat predicts the general capacity to respond to antidepressants. Amygdala hyper-reactivity to sad emotion is involved in a specific non-response to a serotonin–norepinephrine reuptake inhibitor. The findings suggest amygdala probes may help inform the personal selection of antidepressant treatments. PMID:25824424

  9. GABAergic neurons in ferret visual cortex participate in functionally specific networks

    PubMed Central

    Wilson, Daniel E.; Smith, Gordon B.; Jacob, Amanda; Walker, Theo; Dimidschstein, Jordane; Fishell, Gord J.; Fitzpatrick, David

    2017-01-01

    Summary Functional circuits in the visual cortex require the coordinated activity of excitatory and inhibitory neurons. Molecular genetic approaches in the mouse have led to the ‘local nonspecific pooling principle’ of inhibitory connectivity, in which inhibitory neurons are untuned for stimulus features due to the random pooling of local inputs. However, it remains unclear whether this principle generalizes to species with a columnar organization of feature selectivity such as carnivores, primates, and humans. Here we use virally-mediated GABAergic-specific GCaMP6f expression to demonstrate that inhibitory neurons in ferret visual cortex respond robustly and selectively to oriented stimuli. We find that the tuning of inhibitory neurons is inconsistent with the local non-specific pooling of excitatory inputs, and that inhibitory neurons exhibit orientation-specific noise correlations with local and distant excitatory neurons. These findings challenge the generality of the non-specific pooling principle for inhibitory neurons, suggesting different rules for functional excitatory-inhibitory interactions in non-murine species. PMID:28279352

  10. Health Status of Individuals With Serious Mental Illness

    PubMed Central

    Dickerson, Faith B.; Brown, Clayton H.; Daumit, Gail L.; LiJuan, Fang; Goldberg, Richard W.; Wohlheiter, Karen; Dixon, Lisa B.

    2006-01-01

    We examined indices of the health of persons with serious mental illness. A sample of 100 adults with schizophrenia and 100 with major mood disorder were recruited from randomly selected outpatients who were receiving community-based psychiatric treatment. Participants were surveyed about health indicators using items from the National Health and Nutrition Examination Study III and the National Health Interview Survey. Their responses were compared with those of matched samples from the general population surveys. A total of 1% of persons with serious mental illness, compared with 10% from the general population sample, met criteria for all 5 of selected health indicators: nonsmoker, exercise that meets recommended standards, good dentition, absence of obesity, and absence of serious medical co-occurring illness. Within the mentally ill group, educational level, but not a diagnosis of schizophrenia versus mood disorder, was independently associated with a composite measure of health behaviors. We conclude that an examination of multiple health indicators may be used to measure overall health status in persons with serious mental illness. PMID:16469943

  11. Dual Fractal Dimension and Long-Range Correlation of Chinese Stock Prices

    NASA Astrophysics Data System (ADS)

    Chen, Chaoshi; Wang, Lei

    2012-03-01

    The recently developed modified inverse random midpoint displacement (mIRMD) and conventional detrended fluctuation analysis (DFA) algorithms are used to analyze the tick-by-tick high-frequency time series of Chinese A-share stock prices and indexes. A dual-fractal structure with a crossover at about 10 min is observed. The majority of the selected time series show visible persistence within this time threshold, but approach a random walk on a longer time scale. The phenomenon is found to be industry-dependent, i.e., the crossover is much more prominent for stocks belonging to cyclical industries than for those belonging to noncyclical (defensive) industries. We have also shown that the sign series show a similar dual-fractal structure, while like generally found, the magnitude series show a much longer time persistence.

  12. Summer Roost Tree Selection by Eastern Red, Seminole, and Evening Bats in the Upper Coastal Plain of South Carolina

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menzel, M.A.; Carter, T.C.; Ford, W.M.

    Radiotraction of six eastern red bats, six seminole bats and twenty-four evening bats to 55, 61, and 65 day roosts during 1996 to 1997 in the Upper Coastal Plain of South Carolina. For each species, testing was done for differences between used roost trees and randomly located trees. Also tested for differences between habitat characteristics surrounding roost trees and randomly located trees. Eastern Red and Seminole bats generally roosted in canopies of hardwood and pine while clinging to foilage and small branches. Evening bats roosted in cavities or under exfoliating bark in pines and dead snags. Forest management strategies namedmore » within the study should be beneficial for providing roosts in the Upper Coastal Plain of South Carolina.« less

  13. Strategy to recognize and initiate treatment of chronic heart failure in primary care (STRETCH): a cluster randomized trial.

    PubMed

    van Riet, Evelien E S; Hoes, Arno W; Limburg, Alexander; van der Hoeven, Henk; Landman, Marcel A J; Rutten, Frans H

    2014-01-08

    Most patients with heart failure are diagnosed and managed in primary care, however, underdiagnosis and undertreatment are common. We assessed whether implementation of a diagnostic-therapeutic strategy improves functionality, health-related quality of life, and uptake of heart failure medication in primary care. A selective screening study followed by a single-blind cluster randomized trial in primary care. The study population consists of patients aged 65 years or over who presented themselves to the general practitioner in the previous 12 months with shortness of breath on exertion. Patients already known with established heart failure, confirmed by echocardiography, are excluded. Diagnostic investigations include history taking, physical examination, electrocardiography, and serum N-terminal pro B-type natriuretic peptide levels. Only participants with an abnormal electrocardiogram or an N-terminal pro B-type natriuretic peptide level exceeding the exclusionary cutpoint for non-acute onset heart failure (> 15 pmol/L (≈ 125 pg/ml)) will undergo open-access echocardiography. The diagnosis of heart failure (with reduced or preserved ejection fraction) is established by an expert panel consisting of two cardiologists and a general practitioner, according to the criteria of the European Society of Cardiology guidelines.Patients with newly established heart failure are allocated to either the 'care as usual' group or the 'intervention' group. Randomization is at the level of the general practitioner. In the intervention group general practitioners receive a single half-day training in heart failure management and the use of a structured up-titration scheme. All participants fill out quality of life questionnaires at baseline and after six months of follow-up. A six-minute walking test will be performed in patients with heart failure. Information on medication and hospitalization rates is extracted from the electronic medical files of the general practitioners. This study will provide information on the prevalence of unrecognized heart failure in elderly with shortness of breath on exertion, and the randomized comparison will reveal whether management based on a half-day training of general practitioners in the practical application of an up-titration scheme results in improvements in functionality, health-related quality of life, and uptake of heart failure medication in heart failure patients compared to care as usual. ClinicalTrials.gov NCT01202006.

  14. Random waves in the brain: Symmetries and defect generation in the visual cortex

    NASA Astrophysics Data System (ADS)

    Schnabel, M.; Kaschube, M.; Löwel, S.; Wolf, F.

    2007-06-01

    How orientation maps in the visual cortex of the brain develop is a matter of long standing debate. Experimental and theoretical evidence suggests that their development represents an activity-dependent self-organization process. Theoretical analysis [1] exploring this hypothesis predicted that maps at an early developmental stage are realizations of Gaussian random fields exhibiting a rigorous lower bound for their densities of topological defects, called pinwheels. As a consequence, lower pinwheel densities, if observed in adult animals, are predicted to develop through the motion and annihilation of pinwheel pairs. Despite of being valid for a large class of developmental models this result depends on the symmetries of the models and thus of the predicted random field ensembles. In [1] invariance of the orientation map's statistical properties under independent space rotations and orientation shifts was assumed. However, full rotation symmetry appears to be broken by interactions of cortical neurons, e.g. selective couplings between groups of neurons with collinear orientation preferences [2]. A recently proposed new symmetry, called shift-twist symmetry [3], stating that spatial rotations have to occur together with orientation shifts in order to be an appropriate symmetry transformation, is more consistent with this organization. Here we generalize our random field approach to this important symmetry class. We propose a new class of shift-twist symmetric Gaussian random fields and derive the general correlation functions of this ensemble. It turns out that despite strong effects of the shift-twist symmetry on the structure of the correlation functions and on the map layout the lower bound on the pinwheel densities remains unaffected, predicting pinwheel annihilation in systems with low pinwheel densities.

  15. Working situation of cancer survivors versus the general population.

    PubMed

    Lee, Myung Kyung; Yun, Young Ho

    2015-06-01

    The purposes of this study were to compare the working situation of cancer survivors and the general (cancer-free) population and investigate characteristics associated with the increased likelihood of unemployment between the two groups. We selected 1927 cancer survivors from the 2008 Korean Community Health Survey data less than 65 years of age and used propensity score matching to randomly select 1924 individuals from the general population who closely resembled the cancer survivors. Compared to the general population, cancer survivors were less likely to be engaged in paid work, particularly as permanent workers, and were more likely to work regular hours. Additionally, they tended to do less work that involved lifting or moving heavy objects and uncomfortable postures and were more willing to express their emotions. An increased probability of unemployment among cancer survivors was associated with being over 50 years old, being female, having a lower monthly income, having multiple comorbidities, belonging to a nuclear family, being a National Basic Livelihood Act beneficiary, and having a recent diagnosis. Cancer survivors may want to pursue flexible occupations and improve their working situation. Further, they perceive their workplace more positively compared to the general population. Respecting the cancer survivor's choice to find flexible working conditions that suit their health needs and status, health-care providers involved in managing work-related issues among cancer survivors should be aware of the interaction between work-related concerns and post-cancer disease management.

  16. Extension of mixture-of-experts networks for binary classification of hierarchical data.

    PubMed

    Ng, Shu-Kay; McLachlan, Geoffrey J

    2007-09-01

    For many applied problems in the context of medically relevant artificial intelligence, the data collected exhibit a hierarchical or clustered structure. Ignoring the interdependence between hierarchical data can result in misleading classification. In this paper, we extend the mechanism for mixture-of-experts (ME) networks for binary classification of hierarchical data. Another extension is to quantify cluster-specific information on data hierarchy by random effects via the generalized linear mixed-effects model (GLMM). The extension of ME networks is implemented by allowing for correlation in the hierarchical data in both the gating and expert networks via the GLMM. The proposed model is illustrated using a real thyroid disease data set. In our study, we consider 7652 thyroid diagnosis records from 1984 to early 1987 with complete information on 20 attribute values. We obtain 10 independent random splits of the data into a training set and a test set in the proportions 85% and 15%. The test sets are used to assess the generalization performance of the proposed model, based on the percentage of misclassifications. For comparison, the results obtained from the ME network with independence assumption are also included. With the thyroid disease data, the misclassification rate on test sets for the extended ME network is 8.9%, compared to 13.9% for the ME network. In addition, based on model selection methods described in Section 2, a network with two experts is selected. These two expert networks can be considered as modeling two groups of patients with high and low incidence rates. Significant variation among the predicted cluster-specific random effects is detected in the patient group with low incidence rate. It is shown that the extended ME network outperforms the ME network for binary classification of hierarchical data. With the thyroid disease data, useful information on the relative log odds of patients with diagnosed conditions at different periods can be evaluated. This information can be taken into consideration for the assessment of treatment planning of the disease. The proposed extended ME network thus facilitates a more general approach to incorporate data hierarchy mechanism in network modeling.

  17. Naturalistic and Experimental Analyses of Word Frequency and Neighborhood Density Effects in Slips of the Ear*

    PubMed Central

    Vitevitch, Michael S.

    2008-01-01

    A comparison of the lexical characteristics of 88 auditory misperceptions (i.e., slips of the ear) showed no difference in word-frequency, neighborhood density, and neighborhood frequency between the actual and the perceived utterances. Another comparison of slip of the ear tokens (i.e., actual and perceived utterances) and words in general (i.e., randomly selected from the lexicon) showed that slip of the ear tokens had denser neighborhoods and higher neighborhood frequency than words in general, as predicted from laboratory studies. Contrary to prediction, slip of the ear tokens were higher in frequency of occurrence than words in general. Additional laboratory-based investigations examined the possible source of the contradictory word frequency finding, highlighting the importance of using naturalistic and experimental data to develop models of spoken language processing. PMID:12866911

  18. Randomization in clinical trials in orthodontics: its significance in research design and methods to achieve it.

    PubMed

    Pandis, Nikolaos; Polychronopoulou, Argy; Eliades, Theodore

    2011-12-01

    Randomization is a key step in reducing selection bias during the treatment allocation phase in randomized clinical trials. The process of randomization follows specific steps, which include generation of the randomization list, allocation concealment, and implementation of randomization. The phenomenon in the dental and orthodontic literature of characterizing treatment allocation as random is frequent; however, often the randomization procedures followed are not appropriate. Randomization methods assign, at random, treatment to the trial arms without foreknowledge of allocation by either the participants or the investigators thus reducing selection bias. Randomization entails generation of random allocation, allocation concealment, and the actual methodology of implementing treatment allocation randomly and unpredictably. Most popular randomization methods include some form of restricted and/or stratified randomization. This article introduces the reasons, which make randomization an integral part of solid clinical trial methodology, and presents the main randomization schemes applicable to clinical trials in orthodontics.

  19. Isokinetic imbalance of adductor-abductor hip muscles in professional soccer players with chronic adductor-related groin pain.

    PubMed

    Belhaj, K; Meftah, S; Mahir, L; Lmidmani, F; Elfatimi, A

    2016-11-01

    This study aims to compare the isokinetic profile of hip abductor and adductor muscle groups between soccer players suffering from chronic adductor-related groin pain (ARGP), soccer players without ARGP and healthy volunteers from general population. Study included 36 male professional soccer players, who were randomly selected and followed-up over two years. Of the 21 soccer players eligible to participate in the study, 9 players went on to develop chronic ARGP and 12 players did not. Ten healthy male volunteers were randomly selected from the general population as a control group. Comparison between the abductor and adductor muscle peak torques for players with and without chronic ARGP found a statistically significant difference on the dominant and non-dominant sides (p < .005), with the abductor muscle significantly stronger than the adductor muscle. In the group of healthy volunteers, the adductor muscle groups were significantly stronger than the abductor muscle groups on both dominant and non-dominant sides (p < .05). For the group of players who had developed chronic ARGP, abductor-adductor torque ratios were significantly higher on the affected side (p = .008). The adductor muscle strength was also significantly decreased on the affected side. This imbalance appears to be a risk factor for adductor-related groin injury. Therefore, restoring the correct relationship between these two agonist and antagonist hip muscles may be an important preventative measure that should be a primary concern of training and rehabilitation programmes.

  20. Prioritizing Conservation of Ungulate Calving Resources in Multiple-Use Landscapes

    PubMed Central

    Dzialak, Matthew R.; Harju, Seth M.; Osborn, Robert G.; Wondzell, John J.; Hayden-Wing, Larry D.; Winstead, Jeffrey B.; Webb, Stephen L.

    2011-01-01

    Background Conserving animal populations in places where human activity is increasing is an ongoing challenge in many parts of the world. We investigated how human activity interacted with maternal status and individual variation in behavior to affect reliability of spatially-explicit models intended to guide conservation of critical ungulate calving resources. We studied Rocky Mountain elk (Cervus elaphus) that occupy a region where 2900 natural gas wells have been drilled. Methodology/Principal Findings We present novel applications of generalized additive modeling to predict maternal status based on movement, and of random-effects resource selection models to provide population and individual-based inference on the effects of maternal status and human activity. We used a 2×2 factorial design (treatment vs. control) that included elk that were either parturient or non-parturient and in areas either with or without industrial development. Generalized additive models predicted maternal status (parturiency) correctly 93% of the time based on movement. Human activity played a larger role than maternal status in shaping resource use; elk showed strong spatiotemporal patterns of selection or avoidance and marked individual variation in developed areas, but no such pattern in undeveloped areas. This difference had direct consequences for landscape-level conservation planning. When relative probability of use was calculated across the study area, there was disparity throughout 72–88% of the landscape in terms of where conservation intervention should be prioritized depending on whether models were based on behavior in developed areas or undeveloped areas. Model validation showed that models based on behavior in developed areas had poor predictive accuracy, whereas the model based on behavior in undeveloped areas had high predictive accuracy. Conclusions/Significance By directly testing for differences between developed and undeveloped areas, and by modeling resource selection in a random-effects framework that provided individual-based inference, we conclude that: 1) amplified selection or avoidance behavior and individual variation, as responses to increasing human activity, complicate conservation planning in multiple-use landscapes, and 2) resource selection behavior in places where human activity is predictable or less dynamic may provide a more reliable basis from which to prioritize conservation action. PMID:21297866

  1. Estimation of breeding values using selected pedigree records.

    PubMed

    Morton, Richard; Howarth, Jordan M

    2005-06-01

    Fish bred in tanks or ponds cannot be easily tagged individually. The parentage of any individual may be determined by DNA fingerprinting, but is sufficiently expensive that large numbers cannot be so finger-printed. The measurement of the objective trait can be made on a much larger sample relatively cheaply. This article deals with experimental designs for selecting individuals to be finger-printed and for the estimation of the individual and family breeding values. The general setup provides estimates for both genetic effects regarded as fixed or random and for fixed effects due to known regressors. The family effects can be well estimated when even very small numbers are finger-printed, provided that they are the individuals with the most extreme phenotypes.

  2. A statistical evaluation of effective time constants of random telegraph noise with various operation timings of in-pixel source follower transistors

    NASA Astrophysics Data System (ADS)

    Yonezawa, A.; Kuroda, R.; Teramoto, A.; Obara, T.; Sugawa, S.

    2014-03-01

    We evaluated effective time constants of random telegraph noise (RTN) with various operation timings of in-pixel source follower transistors statistically, and discuss the dependency of RTN time constants on the duty ratio (on/off ratio) of MOSFET which is controlled by the gate to source voltage (VGS). Under a general readout operation of CMOS image sensor (CIS), the row selected pixel-source followers (SFs) turn on and not selected pixel-SFs operate at different bias conditions depending on the select switch position; when select switch locate in between the SF driver and column output line, SF drivers nearly turn off. The duty ratio and cyclic period of selected time of SF driver depends on the operation timing determined by the column read out sequence. By changing the duty ratio from 1 to 7.6 x 10-3, time constant ratio of RTN (time to capture <τc<)/(time to emission <τe<) of a part of MOSFETs increased while RTN amplitudes were almost the same regardless of the duty ratio. In these MOSFETs, <τc< increased and the majority of <τe< decreased and the minority of <τe< increased by decreasing the duty ratio. The same tendencies of behaviors of <τc< and <τe< were obtained when VGS was decreased. This indicates that the effective <τc< and <τe< converge to those under off state as duty ratio decreases. These results are important for the noise reduction, detection and analysis of in pixel-SF with RTN.

  3. The effects of educating mothers and girls on the girls' attitudes toward puberty health: a randomized controlled trial.

    PubMed

    Afsari, Atousa; Mirghafourvand, Mojgan; Valizadeh, Sousan; Abbasnezhadeh, Massomeh; Galshi, Mina; Fatahi, Samira

    2017-04-01

    The attitude of a girl toward her menstruation and puberty has a considerable impact on her role during motherhood, social adjustment, and future marital life. This study was conducted in 2014 with the aim of comparing the effects of educating mothers and girls on the attitudes of adolescent girls of Tabriz City, Iran, towards puberty health. This randomized control clinical trial was conducted on 364 adolescent girls who experienced menstruation. Twelve schools were selected randomly among 107 secondary schools for girls. One-third of the students of each school were selected randomly using a table of random numbers and socio-demographic and each participant was asked to answer the attitude questionnaires. The schools were randomly allocated to the groups of mother's education, girl's education, and no-intervention. The attitude questionnaire was filled out by the participants again 2 months after intervention. The general linear model, in which the baseline values were controlled, was employed to compare the scores of the three groups after the intervention. No significant differences were observed among the three groups in terms of the attitude score before intervention (p>0.05). Attitude score improvement after intervention in the girl's education group was significantly higher than the one of both mother's education (adjusted mean difference [AMD]: 1.8; [95% confidence interval (CI): 0.4-1.3]) and no-intervention groups (AMD: 1.3; [95% CI: 0.0-2.6]) by controlling the attitude score before intervention. Based on the findings, it is more effective to educate girls directly about puberty health to improve adolescent girls' attitudes than educating mothers and asking them to transfer information to the girls. Nevertheless, studies with longer training period and follow-up are proposed to determine the effects of educating girls (through their mothers) on their attitudes about puberty health.

  4. Evolutionary dynamics on any population structure

    NASA Astrophysics Data System (ADS)

    Allen, Benjamin; Lippner, Gabor; Chen, Yu-Ting; Fotouhi, Babak; Momeni, Naghmeh; Yau, Shing-Tung; Nowak, Martin A.

    2017-03-01

    Evolution occurs in populations of reproducing individuals. The structure of a population can affect which traits evolve. Understanding evolutionary game dynamics in structured populations remains difficult. Mathematical results are known for special structures in which all individuals have the same number of neighbours. The general case, in which the number of neighbours can vary, has remained open. For arbitrary selection intensity, the problem is in a computational complexity class that suggests there is no efficient algorithm. Whether a simple solution for weak selection exists has remained unanswered. Here we provide a solution for weak selection that applies to any graph or network. Our method relies on calculating the coalescence times of random walks. We evaluate large numbers of diverse population structures for their propensity to favour cooperation. We study how small changes in population structure—graph surgery—affect evolutionary outcomes. We find that cooperation flourishes most in societies that are based on strong pairwise ties.

  5. Random Evolutionary Dynamics Driven by Fitness and House-of-Cards Mutations: Sampling Formulae

    NASA Astrophysics Data System (ADS)

    Huillet, Thierry E.

    2017-07-01

    We first revisit the multi-allelic mutation-fitness balance problem, especially when mutations obey a house of cards condition, where the discrete-time deterministic evolutionary dynamics of the allelic frequencies derives from a Shahshahani potential. We then consider multi-allelic Wright-Fisher stochastic models whose deviation to neutrality is from the Shahshahani mutation/selection potential. We next focus on the weak selection, weak mutation cases and, making use of a Gamma calculus, we compute the normalizing partition functions of the invariant probability densities appearing in their Wright-Fisher diffusive approximations. Using these results, generalized Ewens sampling formulae (ESF) from the equilibrium distributions are derived. We start treating the ESF in the mixed mutation/selection potential case and then we restrict ourselves to the ESF in the simpler house-of-cards mutations only situation. We also address some issues concerning sampling problems from infinitely-many alleles weak limits.

  6. Classification of Medical Datasets Using SVMs with Hybrid Evolutionary Algorithms Based on Endocrine-Based Particle Swarm Optimization and Artificial Bee Colony Algorithms.

    PubMed

    Lin, Kuan-Cheng; Hsieh, Yi-Hsiu

    2015-10-01

    The classification and analysis of data is an important issue in today's research. Selecting a suitable set of features makes it possible to classify an enormous quantity of data quickly and efficiently. Feature selection is generally viewed as a problem of feature subset selection, such as combination optimization problems. Evolutionary algorithms using random search methods have proven highly effective in obtaining solutions to problems of optimization in a diversity of applications. In this study, we developed a hybrid evolutionary algorithm based on endocrine-based particle swarm optimization (EPSO) and artificial bee colony (ABC) algorithms in conjunction with a support vector machine (SVM) for the selection of optimal feature subsets for the classification of datasets. The results of experiments using specific UCI medical datasets demonstrate that the accuracy of the proposed hybrid evolutionary algorithm is superior to that of basic PSO, EPSO and ABC algorithms, with regard to classification accuracy using subsets with a reduced number of features.

  7. A Methodology for Multihazards Load Combinations of Earthquake and Heavy Trucks for Bridges

    PubMed Central

    Wang, Xu; Sun, Baitao

    2014-01-01

    Issues of load combinations of earthquakes and heavy trucks are important contents in multihazards bridge design. Current load resistance factor design (LRFD) specifications usually treat extreme hazards alone and have no probabilistic basis in extreme load combinations. Earthquake load and heavy truck load are considered as random processes with respective characteristics, and the maximum combined load is not the simple superimposition of their maximum loads. Traditional Ferry Borges-Castaneda model that considers load lasting duration and occurrence probability well describes random process converting to random variables and load combinations, but this model has strict constraint in time interval selection to obtain precise results. Turkstra's rule considers one load reaching its maximum value in bridge's service life combined with another load with its instantaneous value (or mean value), which looks more rational, but the results are generally unconservative. Therefore, a modified model is presented here considering both advantages of Ferry Borges-Castaneda's model and Turkstra's rule. The modified model is based on conditional probability, which can convert random process to random variables relatively easily and consider the nonmaximum factor in load combinations. Earthquake load and heavy truck load combinations are employed to illustrate the model. Finally, the results of a numerical simulation are used to verify the feasibility and rationality of the model. PMID:24883347

  8. Effects on readiness to change of an educational intervention on depressive disorders for general physicians in primary care based on a modified Prochaska model--a randomized controlled study.

    PubMed

    Shirazi, M; Zeinaloo, A A; Parikh, S V; Sadeghi, M; Taghva, A; Arbabi, M; Kashani, A Sabouri; Alaeddini, F; Lonka, K; Wahlström, R

    2008-04-01

    The Prochaska model of readiness to change has been proposed to be used in educational interventions to improve medical care. To evaluate the impact on readiness to change of an educational intervention on management of depressive disorders based on a modified version of the Prochaska model in comparison with a standard programme of continuing medical education (CME). This is a randomized controlled trial within primary care practices in southern Tehran, Iran. The participants included 192 general physicians working in primary care (GPs) were recruited after random selection and randomized to intervention (96) and control (96). Intervention consisted of interactive, learner-centred educational methods in large and small group settings depending on the GPs' stages of readiness to change. Change in stage of readiness to change measured by the modified version of the Prochaska questionnaire was the The final number of participants was 78 (81%) in the intervention arm and 81 (84%) in the control arm. Significantly (P < 0.01), more GPs (57/96 = 59% versus 12/96 = 12%) in the intervention group changed to higher stages of readiness to change. The intervention effect was 46% points (P < 0.001) and 50% points (P < 0.001) in the large and small group setting, respectively. Educational formats that suit different stages of learning can support primary care doctors to reach higher stages of behavioural change in the topic of depressive disorders. Our findings have practical implications for conducting CME programmes in Iran and are possibly also applicable in other parts of the world.

  9. Semi-Individualized Homeopathy Add-On Versus Usual Care Only for Premenstrual Disorders: A Randomized, Controlled Feasibility Study.

    PubMed

    Klein-Laansma, Christien T; Jong, Mats; von Hagens, Cornelia; Jansen, Jean Pierre C H; van Wietmarschen, Herman; Jong, Miek C

    2018-03-22

    Premenstrual syndrome and premenstrual dysphoric disorder (PMS/PMDD) bother a substantial number of women. Homeopathy seems a promising treatment, but it needs investigation using reliable study designs. The feasibility of organizing an international randomized pragmatic trial on a homeopathic add-on treatment (usual care [UC] + HT) compared with UC alone was evaluated. A multicenter, randomized, controlled pragmatic trial with parallel groups. The study was organized in general and private homeopathic practices in the Netherlands and Sweden and in an outpatient university clinic in Germany. Women diagnosed as having PMS/PMDD, based on prospective daily rating by the daily record of severity of problems (DRSP) during a period of 2 months, were included and randomized. Women were to receive UC + HT or UC for 4 months. Homeopathic medicine selection was according to a previously tested prognostic questionnaire and electronic algorithm. Usual care was as provided by the women's general practitioner according to their preferences. Before and after treatment, the women completed diaries (DRSP), the measure yourself concerns and well-being, and other questionnaires. Intention-to-treat (ITT) and per protocol (PP) analyses were performed. In Germany, the study could not proceed because of legal limitations. In Sweden, recruitment proved extremely difficult. In the Netherlands and Sweden, 60 women were randomized (UC + HT: 28; UC: 32), data of 47/46 women were analyzed (ITT/PP). After 4 months, relative mean change of DRSP scores in the UC + HT group was significantly better than in the UC group (p = 0.03). With respect to recruitment and different legal status, it does not seem feasible to perform a larger, international, pragmatic randomized trial on (semi-)individualized homeopathy for PMS/PMDD. Since the added value of HT compared with UC was demonstrated by significant differences in symptom score changes, further studies are warranted.

  10. An Overview of Randomization and Minimization Programs for Randomized Clinical Trials

    PubMed Central

    Saghaei, Mahmoud

    2011-01-01

    Randomization is an essential component of sound clinical trials, which prevents selection biases and helps in blinding the allocations. Randomization is a process by which subsequent subjects are enrolled into trial groups only by chance, which essentially eliminates selection biases. A serious consequence of randomization is severe imbalance among the treatment groups with respect to some prognostic factors, which invalidate the trial results or necessitate complex and usually unreliable secondary analysis to eradicate the source of imbalances. Minimization on the other hand tends to allocate in such a way as to minimize the differences among groups, with respect to prognostic factors. Pure minimization is therefore completely deterministic, that is, one can predict the allocation of the next subject by knowing the factor levels of a previously enrolled subject and having the properties of the next subject. To eliminate the predictability of randomization, it is necessary to include some elements of randomness in the minimization algorithms. In this article brief descriptions of randomization and minimization are presented followed by introducing selected randomization and minimization programs. PMID:22606659

  11. Attitudes toward clinical autopsy in unexpected patient deaths in Japan: a nation-wide survey of the general public and physicians.

    PubMed

    Kamishiraki, Etsuko; Maeda, Shoichi; Starkey, Jay; Ikeda, Noriaki

    2012-12-01

    Autopsy is a useful tool for understanding the cause and manner of unexpected patient death. However, the attitudes of the general public and physicians in Japan about clinical autopsy are limited. To describe the beliefs of the general public about whether autopsy should be performed and ascertain if they would actually request one given specific clinical situations where patient death occurred with the additional variable of medical error. To compare these attitudes with previously obtained attitudes of physicians practising at Japanese teaching hospitals. We conducted a cross-sectional study of the general public. We sent standardised questionnaires in 2010 to a randomly selected non-physician adult population using a survey company for participant selection. Respondents gave their opinions about the necessity of autopsy and how they might act given various clinical scenarios of patient death. We compared these results with those of a previous survey of Japanese physicians conducted in 2009. Of the 2300 eligible general adult population, 1575 (68.5%) responded. The majority of the general public indicated they believed an autopsy was necessary. However, in cases of unclear medical error or unclear cause and effect relationship of medical care and patient death, the general public were much less likely to indicate they would actually request an autopsy than were physicians (p<0.0001). Currently in Japan the debate about the role autopsy should play in the case of error related to death is underway. The results from this study will be important in informing related decisions.

  12. The influence of resilience on mental health: The role of general well-being.

    PubMed

    Gao, Tingting; Ding, Xinna; Chai, Jingxin; Zhang, Zhao; Zhang, Han; Kong, Yixi; Mei, Songli

    2017-06-01

    Nurses are suffering from increasing stress, and nursing is recognized as one of the most stressful job. Their mental health problems are serious and worthy of attention. The purpose of this study was to explore the relationship between resilience and mental health and general well-being among nurses. A cross-sectional survey was conducted in 2014, using a self-reported questionnaire. Participants were asked to complete the measure of resilience, mental health, and general well-being. The method of randomly cluster sampling was used to select nurses as participants. A survey of 365 nurses was conducted to test the hypothesized model. This study showed that resilience, mental health, and general well-being correlated with each other. General well-being was an effective predictor of resilience and mental health, whereas it both can moderate and mediate the relationship. Strategies to increase nurses' general well-being could enhance their resilience and reduce mental health problems. It is important to improve the mental health of nurses and maintain the professional values that ensure career sustainability. © 2017 John Wiley & Sons Australia, Ltd.

  13. The RANDOM computer program: A linear congruential random number generator

    NASA Technical Reports Server (NTRS)

    Miles, R. F., Jr.

    1986-01-01

    The RANDOM Computer Program is a FORTRAN program for generating random number sequences and testing linear congruential random number generators (LCGs). The linear congruential form of random number generator is discussed, and the selection of parameters of an LCG for a microcomputer described. This document describes the following: (1) The RANDOM Computer Program; (2) RANDOM.MOD, the computer code needed to implement an LCG in a FORTRAN program; and (3) The RANCYCLE and the ARITH Computer Programs that provide computational assistance in the selection of parameters for an LCG. The RANDOM, RANCYCLE, and ARITH Computer Programs are written in Microsoft FORTRAN for the IBM PC microcomputer and its compatibles. With only minor modifications, the RANDOM Computer Program and its LCG can be run on most micromputers or mainframe computers.

  14. Formulation and Application of the Hierarchical Generalized Random-Situation Random-Weight MIRID

    ERIC Educational Resources Information Center

    Hung, Lai-Fa

    2011-01-01

    The process-component approach has become quite popular for examining many psychological concepts. A typical example is the model with internal restrictions on item difficulty (MIRID) described by Butter (1994) and Butter, De Boeck, and Verhelst (1998). This study proposes a hierarchical generalized random-situation random-weight MIRID. The…

  15. Effects of prey abundance, distribution, visual contrast and morphology on selection by a pelagic piscivore

    USGS Publications Warehouse

    Hansen, Adam G.; Beauchamp, David A.

    2014-01-01

    Most predators eat only a subset of possible prey. However, studies evaluating diet selection rarely measure prey availability in a manner that accounts for temporal–spatial overlap with predators, the sensory mechanisms employed to detect prey, and constraints on prey capture.We evaluated the diet selection of cutthroat trout (Oncorhynchus clarkii) feeding on a diverse planktivore assemblage in Lake Washington to test the hypothesis that the diet selection of piscivores would reflect random (opportunistic) as opposed to non-random (targeted) feeding, after accounting for predator–prey overlap, visual detection and capture constraints.Diets of cutthroat trout were sampled in autumn 2005, when the abundance of transparent, age-0 longfin smelt (Spirinchus thaleichthys) was low, and 2006, when the abundance of smelt was nearly seven times higher. Diet selection was evaluated separately using depth-integrated and depth-specific (accounted for predator–prey overlap) prey abundance. The abundance of different prey was then adjusted for differences in detectability and vulnerability to predation to see whether these factors could explain diet selection.In 2005, cutthroat trout fed non-randomly by selecting against the smaller, transparent age-0 longfin smelt, but for the larger age-1 longfin smelt. After adjusting prey abundance for visual detection and capture, cutthroat trout fed randomly. In 2006, depth-integrated and depth-specific abundance explained the diets of cutthroat trout well, indicating random feeding. Feeding became non-random after adjusting for visual detection and capture. Cutthroat trout selected strongly for age-0 longfin smelt, but against similar sized threespine stickleback (Gasterosteus aculeatus) and larger age-1 longfin smelt in 2006. Overlap with juvenile sockeye salmon (O. nerka) was minimal in both years, and sockeye salmon were rare in the diets of cutthroat trout.The direction of the shift between random and non-random selection depended on the presence of a weak versus a strong year class of age-0 longfin smelt. These fish were easy to catch, but hard to see. When their density was low, poor detection could explain their rarity in the diet. When their density was high, poor detection was compensated by higher encounter rates with cutthroat trout, sufficient to elicit a targeted feeding response. The nature of the feeding selectivity of a predator can be highly dependent on fluctuations in the abundance and suitability of key prey.

  16. Satisfiability Test with Synchronous Simulated Annealing on the Fujitsu AP1000 Massively-Parallel Multiprocessor

    NASA Technical Reports Server (NTRS)

    Sohn, Andrew; Biswas, Rupak

    1996-01-01

    Solving the hard Satisfiability Problem is time consuming even for modest-sized problem instances. Solving the Random L-SAT Problem is especially difficult due to the ratio of clauses to variables. This report presents a parallel synchronous simulated annealing method for solving the Random L-SAT Problem on a large-scale distributed-memory multiprocessor. In particular, we use a parallel synchronous simulated annealing procedure, called Generalized Speculative Computation, which guarantees the same decision sequence as sequential simulated annealing. To demonstrate the performance of the parallel method, we have selected problem instances varying in size from 100-variables/425-clauses to 5000-variables/21,250-clauses. Experimental results on the AP1000 multiprocessor indicate that our approach can satisfy 99.9 percent of the clauses while giving almost a 70-fold speedup on 500 processors.

  17. Group Counseling With Emotionally Disturbed School Children in Taiwan.

    ERIC Educational Resources Information Center

    Chiu, Peter

    The application of group counseling to emotionally disturbed school children in Chinese culture was examined. Two junior high schools located in Tao-Yuan Province were randomly selected with two eighth-grade classes randomly selected from each school. Ten emotionally disturbed students were chosen from each class and randomly assigned to two…

  18. On Measuring and Reducing Selection Bias with a Quasi-Doubly Randomized Preference Trial

    ERIC Educational Resources Information Center

    Joyce, Ted; Remler, Dahlia K.; Jaeger, David A.; Altindag, Onur; O'Connell, Stephen D.; Crockett, Sean

    2017-01-01

    Randomized experiments provide unbiased estimates of treatment effects, but are costly and time consuming. We demonstrate how a randomized experiment can be leveraged to measure selection bias by conducting a subsequent observational study that is identical in every way except that subjects choose their treatment--a quasi-doubly randomized…

  19. Genetic evaluation and selection response for growth in meat-type quail through random regression models using B-spline functions and Legendre polynomials.

    PubMed

    Mota, L F M; Martins, P G M A; Littiere, T O; Abreu, L R A; Silva, M A; Bonafé, C M

    2018-04-01

    The objective was to estimate (co)variance functions using random regression models (RRM) with Legendre polynomials, B-spline function and multi-trait models aimed at evaluating genetic parameters of growth traits in meat-type quail. A database containing the complete pedigree information of 7000 meat-type quail was utilized. The models included the fixed effects of contemporary group and generation. Direct additive genetic and permanent environmental effects, considered as random, were modeled using B-spline functions considering quadratic and cubic polynomials for each individual segment, and Legendre polynomials for age. Residual variances were grouped in four age classes. Direct additive genetic and permanent environmental effects were modeled using 2 to 4 segments and were modeled by Legendre polynomial with orders of fit ranging from 2 to 4. The model with quadratic B-spline adjustment, using four segments for direct additive genetic and permanent environmental effects, was the most appropriate and parsimonious to describe the covariance structure of the data. The RRM using Legendre polynomials presented an underestimation of the residual variance. Lesser heritability estimates were observed for multi-trait models in comparison with RRM for the evaluated ages. In general, the genetic correlations between measures of BW from hatching to 35 days of age decreased as the range between the evaluated ages increased. Genetic trend for BW was positive and significant along the selection generations. The genetic response to selection for BW in the evaluated ages presented greater values for RRM compared with multi-trait models. In summary, RRM using B-spline functions with four residual variance classes and segments were the best fit for genetic evaluation of growth traits in meat-type quail. In conclusion, RRM should be considered in genetic evaluation of breeding programs.

  20. Meta-analysis of selective serotonin reuptake inhibitors in patients with depression and coronary heart disease.

    PubMed

    Pizzi, Carmine; Rutjes, Anne Wilhelmina Saskia; Costa, Grazia Maria; Fontana, Fiorella; Mezzetti, Andrea; Manzoli, Lamberto

    2011-04-01

    The occurrence of depression in patients with coronary heart disease (CHD) substantially increases the likelihood of a poorer cardiovascular prognosis. Although antidepressants are generally effective in decreasing depression, their use in patients with CHD is controversial. We carried out a meta-analysis to evaluate the health effects of selective serotonin reuptake inhibitors (SSRIs) versus placebo or no antidepressants in patients with CHD and depression. Observational studies and randomized controlled trials (RCTs) were searched in MEDLINE, EMBASE, PsycINFO, Cochrane Controlled Clinical Trial Register and other trial registries, and references of relevant articles. Primary outcomes were readmission for CHD (including myocardial infarction, unstable angina, and stroke) and all-cause mortality; the secondary outcome was severity of depression symptoms. Seven articles on 6 RCTs involving 2,461 participants were included. One study incorrectly randomized participants, and another was a reanalysis of RCT data. These were considered observational and analyzed separately. When only properly randomized trials were considered (n = 734 patients), patients on SSRIs showed no significant differences in mortality (risk ratio 0.39, 95% confidence interval 0.08 to 2.01) or CHD readmission rates (0.74, 0.44 to 1.23) compared to controls. Conversely, when all studies were included, SSRI use was associated with a significant decrease in CHD readmission (0.63, 0.46 to 0.86) and mortality rates (0.56, 0.35 to 0.88). A significantly greater improvement in depression symptoms was always apparent in patients on SSRIs with all selected indicators. In conclusion, in patients with CHD and depression, SSRI medication decreases depression symptoms and may improve CHD prognosis. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

  1. Validity and power of association testing in family-based sampling designs: evidence for and against the common wisdom.

    PubMed

    Knight, Stacey; Camp, Nicola J

    2011-04-01

    Current common wisdom posits that association analyses using family-based designs have inflated type 1 error rates (if relationships are ignored) and independent controls are more powerful than familial controls. We explore these suppositions. We show theoretically that family-based designs can have deflated type-error rates. Through simulation, we examine the validity and power of family designs for several scenarios: cases from randomly or selectively ascertained pedigrees; and familial or independent controls. Family structures considered are as follows: sibships, nuclear families, moderate-sized and extended pedigrees. Three methods were considered with the χ(2) test for trend: variance correction (VC), weighted (weights assigned to account for genetic similarity), and naïve (ignoring relatedness) as well as the Modified Quasi-likelihood Score (MQLS) test. Selectively ascertained pedigrees had similar levels of disease enrichment; random ascertainment had no such restriction. Data for 1,000 cases and 1,000 controls were created under the null and alternate models. The VC and MQLS methods were always valid. The naïve method was anti-conservative if independent controls were used and valid or conservative in designs with familial controls. The weighted association method was generally valid for independent controls, and was conservative for familial controls. With regard to power, independent controls were more powerful for small-to-moderate selectively ascertained pedigrees, but familial and independent controls were equivalent in the extended pedigrees and familial controls were consistently more powerful for all randomly ascertained pedigrees. These results suggest a more complex situation than previously assumed, which has important implications for study design and analysis. © 2011 Wiley-Liss, Inc.

  2. Early Colorectal Cancer Detected by Machine Learning Model Using Gender, Age, and Complete Blood Count Data.

    PubMed

    Hornbrook, Mark C; Goshen, Ran; Choman, Eran; O'Keeffe-Rosetti, Maureen; Kinar, Yaron; Liles, Elizabeth G; Rust, Kristal C

    2017-10-01

    Machine learning tools identify patients with blood counts indicating greater likelihood of colorectal cancer and warranting colonoscopy referral. To validate a machine learning colorectal cancer detection model on a US community-based insured adult population. Eligible colorectal cancer cases (439 females, 461 males) with complete blood counts before diagnosis were identified from Kaiser Permanente Northwest Region's Tumor Registry. Control patients (n = 9108) were randomly selected from KPNW's population who had no cancers, received at ≥1 blood count, had continuous enrollment from 180 days prior to the blood count through 24 months after the count, and were aged 40-89. For each control, one blood count was randomly selected as the pseudo-colorectal cancer diagnosis date for matching to cases, and assigned a "calendar year" based on the count date. For each calendar year, 18 controls were randomly selected to match the general enrollment's 10-year age groups and lengths of continuous enrollment. Prediction performance was evaluated by area under the curve, specificity, and odds ratios. Area under the receiver operating characteristics curve for detecting colorectal cancer was 0.80 ± 0.01. At 99% specificity, the odds ratio for association of a high-risk detection score with colorectal cancer was 34.7 (95% CI 28.9-40.4). The detection model had the highest accuracy in identifying right-sided colorectal cancers. ColonFlag ® identifies individuals with tenfold higher risk of undiagnosed colorectal cancer at curable stages (0/I/II), flags colorectal tumors 180-360 days prior to usual clinical diagnosis, and is more accurate at identifying right-sided (compared to left-sided) colorectal cancers.

  3. Using Maximum Entropy to Find Patterns in Genomes

    NASA Astrophysics Data System (ADS)

    Liu, Sophia; Hockenberry, Adam; Lancichinetti, Andrea; Jewett, Michael; Amaral, Luis

    The existence of over- and under-represented sequence motifs in genomes provides evidence of selective evolutionary pressures on biological mechanisms such as transcription, translation, ligand-substrate binding, and host immunity. To accurately identify motifs and other genome-scale patterns of interest, it is essential to be able to generate accurate null models that are appropriate for the sequences under study. There are currently no tools available that allow users to create random coding sequences with specified amino acid composition and GC content. Using the principle of maximum entropy, we developed a method that generates unbiased random sequences with pre-specified amino acid and GC content. Our method is the simplest way to obtain maximally unbiased random sequences that are subject to GC usage and primary amino acid sequence constraints. This approach can also be easily be expanded to create unbiased random sequences that incorporate more complicated constraints such as individual nucleotide usage or even di-nucleotide frequencies. The ability to generate correctly specified null models will allow researchers to accurately identify sequence motifs which will lead to a better understanding of biological processes. National Institute of General Medical Science, Northwestern University Presidential Fellowship, National Science Foundation, David and Lucile Packard Foundation, Camille Dreyfus Teacher Scholar Award.

  4. Fitness landscapes, heuristics and technological paradigms: A critique on random search models in evolutionary economics

    NASA Astrophysics Data System (ADS)

    Frenken, Koen

    2001-06-01

    The biological evolution of complex organisms, in which the functioning of genes is interdependent, has been analyzed as "hill-climbing" on NK fitness landscapes through random mutation and natural selection. In evolutionary economics, NK fitness landscapes have been used to simulate the evolution of complex technological systems containing elements that are interdependent in their functioning. In these models, economic agents randomly search for new technological design by trial-and-error and run the risk of ending up in sub-optimal solutions due to interdependencies between the elements in a complex system. These models of random search are legitimate for reasons of modeling simplicity, but remain limited as these models ignore the fact that agents can apply heuristics. A specific heuristic is one that sequentially optimises functions according to their ranking by users of the system. To model this heuristic, a generalized NK-model is developed. In this model, core elements that influence many functions can be distinguished from peripheral elements that affect few functions. The concept of paradigmatic search can then be analytically defined as search that leaves core elements in tact while concentrating on improving functions by mutation of peripheral elements.

  5. Assessing the accuracy and stability of variable selection methods for random forest modeling in ecology.

    PubMed

    Fox, Eric W; Hill, Ryan A; Leibowitz, Scott G; Olsen, Anthony R; Thornbrugh, Darren J; Weber, Marc H

    2017-07-01

    Random forest (RF) modeling has emerged as an important statistical learning method in ecology due to its exceptional predictive performance. However, for large and complex ecological data sets, there is limited guidance on variable selection methods for RF modeling. Typically, either a preselected set of predictor variables are used or stepwise procedures are employed which iteratively remove variables according to their importance measures. This paper investigates the application of variable selection methods to RF models for predicting probable biological stream condition. Our motivating data set consists of the good/poor condition of n = 1365 stream survey sites from the 2008/2009 National Rivers and Stream Assessment, and a large set (p = 212) of landscape features from the StreamCat data set as potential predictors. We compare two types of RF models: a full variable set model with all 212 predictors and a reduced variable set model selected using a backward elimination approach. We assess model accuracy using RF's internal out-of-bag estimate, and a cross-validation procedure with validation folds external to the variable selection process. We also assess the stability of the spatial predictions generated by the RF models to changes in the number of predictors and argue that model selection needs to consider both accuracy and stability. The results suggest that RF modeling is robust to the inclusion of many variables of moderate to low importance. We found no substantial improvement in cross-validated accuracy as a result of variable reduction. Moreover, the backward elimination procedure tended to select too few variables and exhibited numerous issues such as upwardly biased out-of-bag accuracy estimates and instabilities in the spatial predictions. We use simulations to further support and generalize results from the analysis of real data. A main purpose of this work is to elucidate issues of model selection bias and instability to ecologists interested in using RF to develop predictive models with large environmental data sets.

  6. How precise are reported protein coordinate data?

    PubMed

    Konagurthu, Arun S; Allison, Lloyd; Abramson, David; Stuckey, Peter J; Lesk, Arthur M

    2014-03-01

    Atomic coordinates in the Worldwide Protein Data Bank (wwPDB) are generally reported to greater precision than the experimental structure determinations have actually achieved. By using information theory and data compression to study the compressibility of protein atomic coordinates, it is possible to quantify the amount of randomness in the coordinate data and thereby to determine the realistic precision of the reported coordinates. On average, the value of each C(α) coordinate in a set of selected protein structures solved at a variety of resolutions is good to about 0.1 Å.

  7. Preselection statistics and Random Forest classification identify population informative single nucleotide polymorphisms in cosmopolitan and autochthonous cattle breeds.

    PubMed

    Bertolini, F; Galimberti, G; Schiavo, G; Mastrangelo, S; Di Gerlando, R; Strillacci, M G; Bagnato, A; Portolano, B; Fontanesi, L

    2018-01-01

    Commercial single nucleotide polymorphism (SNP) arrays have been recently developed for several species and can be used to identify informative markers to differentiate breeds or populations for several downstream applications. To identify the most discriminating genetic markers among thousands of genotyped SNPs, a few statistical approaches have been proposed. In this work, we compared several methods of SNPs preselection (Delta, F st and principal component analyses (PCA)) in addition to Random Forest classifications to analyse SNP data from six dairy cattle breeds, including cosmopolitan (Holstein, Brown and Simmental) and autochthonous Italian breeds raised in two different regions and subjected to limited or no breeding programmes (Cinisara, Modicana, raised only in Sicily and Reggiana, raised only in Emilia Romagna). From these classifications, two panels of 96 and 48 SNPs that contain the most discriminant SNPs were created for each preselection method. These panels were evaluated in terms of the ability to discriminate as a whole and breed-by-breed, as well as linkage disequilibrium within each panel. The obtained results showed that for the 48-SNP panel, the error rate increased mainly for autochthonous breeds, probably as a consequence of their admixed origin lower selection pressure and by ascertaining bias in the construction of the SNP chip. The 96-SNP panels were generally more able to discriminate all breeds. The panel derived by PCA-chrom (obtained by a preselection chromosome by chromosome) could identify informative SNPs that were particularly useful for the assignment of minor breeds that reached the lowest value of Out Of Bag error even in the Cinisara, whose value was quite high in all other panels. Moreover, this panel contained also the lowest number of SNPs in linkage disequilibrium. Several selected SNPs are located nearby genes affecting breed-specific phenotypic traits (coat colour and stature) or associated with production traits. In general, our results demonstrated the usefulness of Random Forest in combination to other reduction techniques to identify population informative SNPs.

  8. The Effect of Orem's Self-Care Model on Quality of Life in Patients with Migraine: a Randomized Clinical Trial.

    PubMed

    Mahmoudzadeh Zarandi, Fatemeh; Raiesifar, Afsaneh; Ebadi, Abbas

    2016-03-01

    Many aspects of the lives of migraineurs are commonly affected by the condition, including occupational affairs, social and family life, responsibilities and ultimately the quality of life. This study was designed to determine the effect of orem's self-care nursing model on quality of life in patients with a migraine. This study was carried out in Tehran, Iran. According to the pre-post design of the randomized clinical trial, 88 patients were selected. After obtaining approval from the ethics committee of the Baqiyatallah Medical Sciences University's Research Deputy; Patients who signed the informed consent aged 20-55 years and without any more disease or disability affecting the quality of life were selected and randomly assigned to a group. Data collection tools were a demographic questionnaire, general health survey short form (SF36), and Orem cognition form and self-care checklist. Self-care model were held as four 30-45 minutes training sessions based on self-care deficit needs for the experimental group. The quality of life scores was measured in two stages, before and three months after intervention then were compared in both groups. Data were analyzed with statistical software SPSS and use of descriptive analysis tests, Chi-square, Mann-Whitney u and Wilcoxon. The final analysis was performed on 43 experimental and 40 controls. No significant difference was detected in the two groups in terms of demographic variables (P>0.05). All dimensions of quality of life including physical functioning, physical role limitation, body pain, general health, vitality, social functioning and emotional role limitation and mental health in the experimental group showed a significant increase after intervention compared to the control group (P<0.05). It was concluded that performing Orem's self-care nursing model improves function and overall quality of life and reduces the high cost of a migraine and migraine-related disability to individuals and society.

  9. Prospects for Genomic Selection in Cassava Breeding.

    PubMed

    Wolfe, Marnin D; Del Carpio, Dunia Pino; Alabi, Olumide; Ezenwaka, Lydia C; Ikeogu, Ugochukwu N; Kayondo, Ismail S; Lozano, Roberto; Okeke, Uche G; Ozimati, Alfred A; Williams, Esuma; Egesi, Chiedozie; Kawuki, Robert S; Kulakow, Peter; Rabbi, Ismail Y; Jannink, Jean-Luc

    2017-11-01

    Cassava ( Crantz) is a clonally propagated staple food crop in the tropics. Genomic selection (GS) has been implemented at three breeding institutions in Africa to reduce cycle times. Initial studies provided promising estimates of predictive abilities. Here, we expand on previous analyses by assessing the accuracy of seven prediction models for seven traits in three prediction scenarios: cross-validation within populations, cross-population prediction and cross-generation prediction. We also evaluated the impact of increasing the training population (TP) size by phenotyping progenies selected either at random or with a genetic algorithm. Cross-validation results were mostly consistent across programs, with nonadditive models predicting of 10% better on average. Cross-population accuracy was generally low (mean = 0.18) but prediction of cassava mosaic disease increased up to 57% in one Nigerian population when data from another related population were combined. Accuracy across generations was poorer than within-generation accuracy, as expected, but accuracy for dry matter content and mosaic disease severity should be sufficient for rapid-cycling GS. Selection of a prediction model made some difference across generations, but increasing TP size was more important. With a genetic algorithm, selection of one-third of progeny could achieve an accuracy equivalent to phenotyping all progeny. We are in the early stages of GS for this crop but the results are promising for some traits. General guidelines that are emerging are that TPs need to continue to grow but phenotyping can be done on a cleverly selected subset of individuals, reducing the overall phenotyping burden. Copyright © 2017 Crop Science Society of America.

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

    PubMed

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

    2012-09-01

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

  11. An analysis of the attitudes of dental patients attending general dental practice in Galway.

    PubMed

    Hayes, Martina; Burke, Francis; McKenna, Gerald; Madden, Jamie; Cronin, Michael

    2013-01-01

    To describe the patterns of dental attendance and attitudes towards tooth loss of general dental practice patients in Galway. 1. To determine the pattern of adult dental attendance in general practices in Galway; and, 2. To examine the oral health attitudes of these patients. Questionnaires were distributed to 311 consecutive adult patients in the waiting rooms of ten general dental practices in Galway, which were randomly selected from the telephone directory. A total of 254 of the 311 questionnaires distributed were fully completed, returned and included in the results, giving a response rate of 81.7%. A total of 59% of dentate participants attended their dentist for annual or biannual examinations compared to 23% of edentate patients. Some 10.5% of medical card holders and 0.5% of non-medical card holders were edentulous. The data from the survey indicated that medical card holders in Galway were more likely to be edentulous than nonmedical card holders. Edentate patients were less likely to be regular dental attenders than dentate patients.

  12. Evolution in fluctuating environments: decomposing selection into additive components of the Robertson-Price equation.

    PubMed

    Engen, Steinar; Saether, Bernt-Erik

    2014-03-01

    We analyze the stochastic components of the Robertson-Price equation for the evolution of quantitative characters that enables decomposition of the selection differential into components due to demographic and environmental stochasticity. We show how these two types of stochasticity affect the evolution of multivariate quantitative characters by defining demographic and environmental variances as components of individual fitness. The exact covariance formula for selection is decomposed into three components, the deterministic mean value, as well as stochastic demographic and environmental components. We show that demographic and environmental stochasticity generate random genetic drift and fluctuating selection, respectively. This provides a common theoretical framework for linking ecological and evolutionary processes. Demographic stochasticity can cause random variation in selection differentials independent of fluctuating selection caused by environmental variation. We use this model of selection to illustrate that the effect on the expected selection differential of random variation in individual fitness is dependent on population size, and that the strength of fluctuating selection is affected by how environmental variation affects the covariance in Malthusian fitness between individuals with different phenotypes. Thus, our approach enables us to partition out the effects of fluctuating selection from the effects of selection due to random variation in individual fitness caused by demographic stochasticity. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  13. Dissecting protein:protein interactions between transcription factors with an RNA aptamer.

    PubMed Central

    Tian, Y; Adya, N; Wagner, S; Giam, C Z; Green, M R; Ellington, A D

    1995-01-01

    Nucleic acid aptamers isolated from random sequence pools have generally proven useful at inhibiting the interactions of nucleic acid binding proteins with their cognate nucleic acids. In order to develop reagents that could also be used to study protein:protein interactions, we have used in vitro selection to search for RNA aptamers that could interact with the transactivating protein Tax from human T-cell leukemia virus. Tax does not normally bind to nucleic acids, but instead stimulates transcription by interacting with a variety of cellular transcription factors, including the cyclic AMP-response element binding protein (CREB), NF-kappa B, and the serum response factor (SRF). Starting from a pool of greater than 10(13) different RNAs with a core of 120 random sequence positions, RNAs were selected for their ability to be co-retained on nitrocellulose filters with Tax. After five cycles of selection and amplification, a single nucleic acid species remained. This aptamer was found to bind Tax with high affinity and specificity, and could disrupt complex formation between Tax and NF-kappa B, but not with SRF. The differential effects of our aptamer probe on protein:protein interactions suggest a model for how the transcription factor binding sites on the surface of the Tax protein are organized. This model is consistent with data from a variety of other studies. PMID:7489503

  14. Do the Hard Things First: A Randomized Controlled Trial Testing the Effects of Exemplar Selection on Generalization Following Therapy for Grammatical Morphology

    PubMed Central

    Fey, Marc; Curran, Maura

    2017-01-01

    Purpose Complexity-based approaches to treatment have been gaining popularity in domains such as phonology and aphasia but have not yet been tested in child morphological acquisition. In this study, we examined whether beginning treatment with easier-to-inflect (easy first) or harder-to-inflect (hard first) verbs led to greater progress in the production of regular past-tense –ed by children with developmental language disorder. Method Eighteen children with developmental language disorder (ages 4–10) participated in a randomized controlled trial (easy first, N = 10, hard first, N = 8). Verbs were selected on the basis of frequency, phonological complexity, and telicity (i.e., the completedness of the event). Progress was measured by the duration of therapy, number of verb lists trained to criterion, and pre/post gains in accuracy for trained and untrained verbs on structured probes. Results The hard-first group made greater gains in accuracy on both trained and untrained verbs but did not have fewer therapy visits or train to criterion on more verb lists than the easy-first group. Treatment fidelity, average recasts per session, and verbs learned did not differ across conditions. Conclusion When targeting grammatical morphemes, it may be most efficient for clinicians to select harder rather than easier exemplars of the target. PMID:28796874

  15. Need for specific sugar-sweetened beverage lessons for fourth- and fifth-graders.

    PubMed

    Bea, Jennifer W; Jacobs, Laurel; Waits, Juanita; Hartz, Vern; Martinez, Stephanie H; Standfast, Rebecca D; Farrell, Vanessa A; Bawden, Margine; Whitmer, Evelyn; Misner, Scottie

    2015-01-01

    Consumption of sugar-sweetened beverages (SSB) is linked to obesity. The authors hypothesized that school-based nutrition education would decrease SSB consumption. Self-selected interventional cohort with random selection for pre and post measurements. Arizona Supplemental Nutrition Assistance Program-Education Program-eligible schools. Randomly selected (9%) fourth- and fifth-grade classroom students. The University of Arizona Nutrition Network provided general nutrition education training and materials to teachers, to be delivered to their students. The University of Arizona Nutrition Network administered behavioral questionnaires to students in both fall and spring. Change in SSB consumption. Descriptive statistics were computed for student demographics and beverage consumption on the day before testing. Paired t tests evaluated change in classroom averages. Linear regression assessed potential correlates of SSB consumption. Fall mean SSB consumption was 1.1 (± 0.2) times; mean milk and water intake were 1.6 (± 0.2) and 5.2 (± 0.7) times, respectively. Beverage consumption increased (3.2%) in springtime, with increased SSBs (14.4%) accounting for the majority (P = .006). Change in SSB consumption was negatively associated with baseline SSB and water consumption but positively associated with baseline milk fat (P ≤ .05). The results suggest the need for beverage-specific education to encourage children to consume more healthful beverages in warmer weather. Copyright © 2015 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  16. An adaptive incremental approach to constructing ensemble classifiers: Application in an information-theoretic computer-aided decision system for detection of masses in mammograms

    PubMed Central

    Mazurowski, Maciej A.; Zurada, Jacek M.; Tourassi, Georgia D.

    2009-01-01

    Ensemble classifiers have been shown efficient in multiple applications. In this article, the authors explore the effectiveness of ensemble classifiers in a case-based computer-aided diagnosis system for detection of masses in mammograms. They evaluate two general ways of constructing subclassifiers by resampling of the available development dataset: Random division and random selection. Furthermore, they discuss the problem of selecting the ensemble size and propose two adaptive incremental techniques that automatically select the size for the problem at hand. All the techniques are evaluated with respect to a previously proposed information-theoretic CAD system (IT-CAD). The experimental results show that the examined ensemble techniques provide a statistically significant improvement (AUC=0.905±0.024) in performance as compared to the original IT-CAD system (AUC=0.865±0.029). Some of the techniques allow for a notable reduction in the total number of examples stored in the case base (to 1.3% of the original size), which, in turn, results in lower storage requirements and a shorter response time of the system. Among the methods examined in this article, the two proposed adaptive techniques are by far the most effective for this purpose. Furthermore, the authors provide some discussion and guidance for choosing the ensemble parameters. PMID:19673196

  17. The effectiveness of Cognitive Behavioral Therapy (CBT) with general exercises versus general exercises alone in the management of chronic low back pain.

    PubMed

    Khan, Muhammad; Akhter, Saeed; Soomro, Rabail Rani; Ali, Syed Shahzad

    2014-07-01

    To evaluate the effectiveness of Cognitive Behavioural Therapy (CBT) along with General exercises and General exercises alone in chronic low back pain. Total 54 patients with chronic low back pain who fulfilled inclusion criteria were recruited from Physiotherapy, Department of Alain Poly Clinic Karachi and Institute of Physical Medicine & Rehabilitation Dow University of Health Sciences Karachi. Selected patients were equally divided and randomly assigned into two groups with simple randomisation method. The Cognitive Behavioural Therapy (CBT) and General exercises group received Operant model of CBT and General Exercises whereas General exercises group received General exercises only. Both groups received a home exercise program as well. Patients in both groups received 3 treatment sessions per week for 12 consecutive weeks. Clinical assessment was performed using Visual Analogue Scale (VAS) and Ronald Morris Disability Questionnaire at baseline and after 12 weeks. Both study groups showed statistically significant improvements in both outcomes measures p=0.000. However, mean improvements in post intervention VAS score and Ronald Morris score was better in CBT and exercises group as compared to General exercise group. In conclusion, both interventions are effective in treating chronic low back pain however; CBT & General exercises are clinically more effective than General exercises alone.

  18. The genetic consequences of selection in natural populations.

    PubMed

    Thurman, Timothy J; Barrett, Rowan D H

    2016-04-01

    The selection coefficient, s, quantifies the strength of selection acting on a genetic variant. Despite this parameter's central importance to population genetic models, until recently we have known relatively little about the value of s in natural populations. With the development of molecular genetic techniques in the late 20th century and the sequencing technologies that followed, biologists are now able to identify genetic variants and directly relate them to organismal fitness. We reviewed the literature for published estimates of natural selection acting at the genetic level and found over 3000 estimates of selection coefficients from 79 studies. Selection coefficients were roughly exponentially distributed, suggesting that the impact of selection at the genetic level is generally weak but can occasionally be quite strong. We used both nonparametric statistics and formal random-effects meta-analysis to determine how selection varies across biological and methodological categories. Selection was stronger when measured over shorter timescales, with the mean magnitude of s greatest for studies that measured selection within a single generation. Our analyses found conflicting trends when considering how selection varies with the genetic scale (e.g., SNPs or haplotypes) at which it is measured, suggesting a need for further research. Besides these quantitative conclusions, we highlight key issues in the calculation, interpretation, and reporting of selection coefficients and provide recommendations for future research. © 2016 John Wiley & Sons Ltd.

  19. A social preference valuations set for EQ-5D health states in Flanders, Belgium.

    PubMed

    Cleemput, Irina

    2010-04-01

    This study aimed at deriving a preference valuation set for EQ-5D health states from the general Flemish public in Belgium. A EuroQol valuation instrument with 16 health states to be valued on a visual analogue scale was sent to a random sample of 2,754 adults. The initial response rate was 35%. Eventually, 548 (20%) respondents provided useable valuations for modeling. Valuations for 245 health states were modeled using a random effects model. The selection of the model was based on two criteria: health state valuations must be consistent, and the difference with the directly observed valuations must be small. A model including a value decrement if any health dimension of the EQ-5D is on the worst level was selected to construct the social health state valuation set. A comparison with health state valuations from other countries showed similarities, especially with those from New Zealand. The use of a single preference valuation set across different health economic evaluations within a country is highly preferable to increase their usability for policy makers. This study contributes to the standardization of outcome measurement in economic evaluations in Belgium.

  20. Summer and winter habitat suitability of Marco Polo argali in southeastern Tajikistan: A modeling approach.

    PubMed

    Salas, Eric Ariel L; Valdez, Raul; Michel, Stefan

    2017-11-01

    We modeled summer and winter habitat suitability of Marco Polo argali in the Pamir Mountains in southeastern Tajikistan using these statistical algorithms: Generalized Linear Model, Random Forest, Boosted Regression Tree, Maxent, and Multivariate Adaptive Regression Splines. Using sheep occurrence data collected from 2009 to 2015 and a set of selected habitat predictors, we produced summer and winter habitat suitability maps and determined the important habitat suitability predictors for both seasons. Our results demonstrated that argali selected proximity to riparian areas and greenness as the two most relevant variables for summer, and the degree of slope (gentler slopes between 0° to 20°) and Landsat temperature band for winter. The terrain roughness was also among the most important variables in summer and winter models. Aspect was only significant for winter habitat, with argali preferring south-facing mountain slopes. We evaluated various measures of model performance such as the Area Under the Curve (AUC) and the True Skill Statistic (TSS). Comparing the five algorithms, the AUC scored highest for Boosted Regression Tree in summer (AUC = 0.94) and winter model runs (AUC = 0.94). In contrast, Random Forest underperformed in both model runs.

  1. Issues affecting the motivation of nuclear medicine technologists in Kuwait.

    PubMed

    Ali, Layla; Abdelsalam, Amal; Muddei, Sara; Brindhaban, Ajit

    2013-01-01

    The demand for nuclear medicine technologists (NMTs) in Kuwait has increased, especially with the introduction of multimodality imaging systems. In order to increase the number of NMTs in the workforce and retain the existing NMTs, there should be a better way to motivate them. To find out how satisfied NMTs are and the factors that motivate them. An interview was conducted with 40 randomly selected NMTs to explore deep-seated emotions and attitudes that were related to motivation. Questions about the recognition NMTs receive from the general public, whether they are acknowledged as significant contributors to health services, ways to improve the standing of NMTs in society, and the clarity of the job description were included. A questionnaire survey was then conducted with 100 randomly selected NMTs. The questions were designed to elicit wider perspective of the information obtained from the interviews. The results show a need for attention in the Ministry of Health to NMTs for recognition, motivation, and improvement. Giving the NMTs their own identity and opportunities to be part of decision-making in the health team would influence more students to join nuclear medicine departments and give more self-confidence to the existing NMTs.

  2. The Coalescent Process in Models with Selection

    PubMed Central

    Kaplan, N. L.; Darden, T.; Hudson, R. R.

    1988-01-01

    Statistical properties of the process describing the genealogical history of a random sample of genes are obtained for a class of population genetics models with selection. For models with selection, in contrast to models without selection, the distribution of this process, the coalescent process, depends on the distribution of the frequencies of alleles in the ancestral generations. If the ancestral frequency process can be approximated by a diffusion, then the mean and the variance of the number of segregating sites due to selectively neutral mutations in random samples can be numerically calculated. The calculations are greatly simplified if the frequencies of the alleles are tightly regulated. If the mutation rates between alleles maintained by balancing selection are low, then the number of selectively neutral segregating sites in a random sample of genes is expected to substantially exceed the number predicted under a neutral model. PMID:3066685

  3. Specific collaborative group intervention for patients with medically unexplained symptoms in general practice: a cluster randomized controlled trial.

    PubMed

    Schaefert, R; Kaufmann, C; Wild, B; Schellberg, D; Boelter, R; Faber, R; Szecsenyi, J; Sauer, N; Guthrie, E; Herzog, W

    2013-01-01

    Patients with medically unexplained symptoms (MUS) are frequent in primary care and substantially impaired in their quality of life (QoL). Specific training of general practitioners (GPs) alone did not demonstrate sustained improvement at later follow-up in current reviews. We evaluated a collaborative group intervention. We conducted a cluster randomized controlled trial. Thirty-five GPs recruited 304 MUS patients (intervention group: 170; control group: 134). All GPs were trained in diagnosis and management of MUS (control condition). Eighteen randomly selected intervention GPs participated in training for a specific collaborative group intervention. They conducted 10 weekly group sessions and 2 booster meetings in their practices, together with a psychosomatic specialist. Six and 12 months after baseline, QoL was assessed with the Short-Form 36. The primary outcome was the physical composite score (PCS), and the secondary outcome was the mental composite score (MCS). At 12 months, intention-to-treat analyses showed a significant between-group effect for the MCS (p = 0.023) but not for the PCS (p = 0.674). This effect was preceded by a significant reduction of somatic symptom severity (15-item somatic symptom severity scale of the Patient Health Questionnaire, PHQ-15) at 6 months (p = 0.008) that lacked significance at 12 months (p = 0.078). As additional between-group effects at 12 months, per-protocol analyses showed less health anxiety (Whiteley-7; p = 0.038) and less psychosocial distress (PHQ; p = 0.024); GP visits were significantly (p = 0.042) reduced in the intervention group. Compared to pure GP training, collaborative group intervention achieved a progressive, clinically meaningful improvement in mental but not physical QoL. It could bridge gaps between general practice and mental health care. Copyright © 2012 S. Karger AG, Basel.

  4. Raloxifene as an Adjunctive Treatment for Postmenopausal Women With Schizophrenia: A 24-Week Double-Blind, Randomized, Parallel, Placebo-Controlled Trial

    PubMed Central

    Usall, Judith; Huerta-Ramos, Elena; Labad, Javier; Cobo, Jesús; Núñez, Christian; Creus, Marta; Parés, Gemma García; Cuadras, Daniel; Franco, José; Miquel, Eva; Reyes, Julio César; Roca, Mercedes

    2016-01-01

    The potential therapeutic utility of estrogens in schizophrenia is increasingly being recognized. Raloxifene, a selective estrogen receptor modulator, appears to act similarly to estrogens on dopamine and serotonin brain systems. One previous trial by our team found that raloxifene was useful to improve negative, positive, and general psychopathological symptoms, without having the negative side effects of estrogens. In this study, we assess the utility of raloxifene in treating negative and other psychotic symptoms in postmenopausal women with schizophrenia exhibiting prominent negative symptoms. This was a 24-week, randomized, parallel, double-blind, placebo-controlled study. Patients were recruited from the inpatient and outpatient departments of Parc Sanitari Sant Joan de Déu, Hospital Universitari Institut Pere Mata, and Corporació Sanitària Parc Taulí. Seventy postmenopausal women with schizophrenia (DSM-IV) were randomized to either adjunctive raloxifene (38 women) or adjunctive placebo (32 women). Psychopathological symptoms were assessed at baseline and at weeks 4, 12, and 24 with the Positive and Negative Syndrome Scale (PANSS) and the Scale for the Assessment of Negative Symptoms (SANS). The addition of raloxifene (60mg/d) to regular antipsychotic treatment significantly reduced negative (P = .027), general (P = .003), and total symptomatology (P = .005) measured with the PANSS during the 24-week trial, as compared to women receiving placebo. Also Alogia SANSS subscale improved more in the raloxifene (P = .048) than the placebo group. In conclusion, raloxifene improved negative and general psychopathological symptoms, compared with antipsychotic medication alone, in postmenopausal women with schizophrenia. These data replicate our previous results with a larger sample and a longer follow-up. Trial registration: NCT01573637. PMID:26591005

  5. Effects of Selected Meditative Asanas on Kinaesthetic Perception and Speed of Movement

    ERIC Educational Resources Information Center

    Singh, Kanwaljeet; Bal, Baljinder S.; Deol, Nishan S.

    2009-01-01

    Study aim: To assess the effects of selected meditative "asanas" on kinesthetic perception and movement speed. Material and methods: Thirty randomly selected male students aged 18-24 years volunteered to participate in the study. They were randomly assigned into two groups: A (medidative) and B (control). The Nelson's movement speed and…

  6. Model Selection with the Linear Mixed Model for Longitudinal Data

    ERIC Educational Resources Information Center

    Ryoo, Ji Hoon

    2011-01-01

    Model building or model selection with linear mixed models (LMMs) is complicated by the presence of both fixed effects and random effects. The fixed effects structure and random effects structure are codependent, so selection of one influences the other. Most presentations of LMM in psychology and education are based on a multilevel or…

  7. Random one-of-N selector

    DOEpatents

    Kronberg, J.W.

    1993-04-20

    An apparatus for selecting at random one item of N items on the average comprising counter and reset elements for counting repeatedly between zero and N, a number selected by the user, a circuit for activating and deactivating the counter, a comparator to determine if the counter stopped at a count of zero, an output to indicate an item has been selected when the count is zero or not selected if the count is not zero. Randomness is provided by having the counter cycle very often while varying the relatively longer duration between activation and deactivation of the count. The passive circuit components of the activating/deactivating circuit and those of the counter are selected for the sensitivity of their response to variations in temperature and other physical characteristics of the environment so that the response time of the circuitry varies. Additionally, the items themselves, which may be people, may vary in shape or the time they press a pushbutton, so that, for example, an ultrasonic beam broken by the item or person passing through it will add to the duration of the count and thus to the randomness of the selection.

  8. Random one-of-N selector

    DOEpatents

    Kronberg, James W.

    1993-01-01

    An apparatus for selecting at random one item of N items on the average comprising counter and reset elements for counting repeatedly between zero and N, a number selected by the user, a circuit for activating and deactivating the counter, a comparator to determine if the counter stopped at a count of zero, an output to indicate an item has been selected when the count is zero or not selected if the count is not zero. Randomness is provided by having the counter cycle very often while varying the relatively longer duration between activation and deactivation of the count. The passive circuit components of the activating/deactivating circuit and those of the counter are selected for the sensitivity of their response to variations in temperature and other physical characteristics of the environment so that the response time of the circuitry varies. Additionally, the items themselves, which may be people, may vary in shape or the time they press a pushbutton, so that, for example, an ultrasonic beam broken by the item or person passing through it will add to the duration of the count and thus to the randomness of the selection.

  9. GDPs' self-perceived confidence and anxiety in their clinical and communication skills used when screening for oral cancer: UK variations.

    PubMed

    Farrand, Paul; Clover, Henry; Hutchison, Iain L

    2003-07-01

    To compare anxieties of general dental practitioners (GDPs) across the UK in communicating with patients about oral cancer and confidence in clinical skills required to perform soft tissue screening for oral cancer. A questionnaire was sent to 2200 randomly selected GDPs from across the UK. Responses to the questionnaires were analysed using 95% confidence intervals. Dental practitioners in general practice within England, Northern Ireland, Scotland and Wales. The response rate varied between 57% in England and 65% in Northern Ireland. A high percentage of dental practitioners across all UK regions reported performing soft tissue examinations (range 78% to 88%). The number of soft tissue examinations per month varied between 129 (95% CI 109, 148) and 162 (95% CI 154, 170) indicating criteria when selecting patients for screening. Using a nine-point rating scale (1 = not at all, 9 = extremely), confidence in the clinical skills required during oral cancer screening was generally good (ratings varying between 5.4 and 6.7). With the exception of reporting positive findings to patients (rating 4.5 to 5.2), anxiety in communication skills used during oral cancer screening was generally low (ratings varying between 1.8 and 3.9). While concerns over generalizing the results exist, the situation with respect to the clinical and communication skills required by GDPs during oral cancer screening is generally encouraging. An area of concern is discussing positive findings with patients. This may be overcome by developing specialist courses on breaking bad news within undergraduate dental curricula and programmes of continuing professional development.

  10. Bayesian dynamic modeling of time series of dengue disease case counts.

    PubMed

    Martínez-Bello, Daniel Adyro; López-Quílez, Antonio; Torres-Prieto, Alexander

    2017-07-01

    The aim of this study is to model the association between weekly time series of dengue case counts and meteorological variables, in a high-incidence city of Colombia, applying Bayesian hierarchical dynamic generalized linear models over the period January 2008 to August 2015. Additionally, we evaluate the model's short-term performance for predicting dengue cases. The methodology shows dynamic Poisson log link models including constant or time-varying coefficients for the meteorological variables. Calendar effects were modeled using constant or first- or second-order random walk time-varying coefficients. The meteorological variables were modeled using constant coefficients and first-order random walk time-varying coefficients. We applied Markov Chain Monte Carlo simulations for parameter estimation, and deviance information criterion statistic (DIC) for model selection. We assessed the short-term predictive performance of the selected final model, at several time points within the study period using the mean absolute percentage error. The results showed the best model including first-order random walk time-varying coefficients for calendar trend and first-order random walk time-varying coefficients for the meteorological variables. Besides the computational challenges, interpreting the results implies a complete analysis of the time series of dengue with respect to the parameter estimates of the meteorological effects. We found small values of the mean absolute percentage errors at one or two weeks out-of-sample predictions for most prediction points, associated with low volatility periods in the dengue counts. We discuss the advantages and limitations of the dynamic Poisson models for studying the association between time series of dengue disease and meteorological variables. The key conclusion of the study is that dynamic Poisson models account for the dynamic nature of the variables involved in the modeling of time series of dengue disease, producing useful models for decision-making in public health.

  11. Population differentiation in Pacific salmon: local adaptation, genetic drift, or the environment?

    USGS Publications Warehouse

    Adkison, Milo D.

    1995-01-01

    Morphological, behavioral, and life-history differences between Pacific salmon (Oncorhynchus spp.) populations are commonly thought to reflect local adaptation, and it is likewise common to assume that salmon populations separated by small distances are locally adapted. Two alternatives to local adaptation exist: random genetic differentiation owing to genetic drift and founder events, and genetic homogeneity among populations, in which differences reflect differential trait expression in differing environments. Population genetics theory and simulations suggest that both alternatives are possible. With selectively neutral alleles, genetic drift can result in random differentiation despite many strays per generation. Even weak selection can prevent genetic drift in stable populations; however, founder effects can result in random differentiation despite selective pressures. Overlapping generations reduce the potential for random differentiation. Genetic homogeneity can occur despite differences in selective regimes when straying rates are high. In sum, localized differences in selection should not always result in local adaptation. Local adaptation is favored when population sizes are large and stable, selection is consistent over large areas, selective diffeentials are large, and straying rates are neither too high nor too low. Consideration of alternatives to local adaptation would improve both biological research and salmon conservation efforts.

  12. Evaluation of some random effects methodology applicable to bird ringing data

    USGS Publications Warehouse

    Burnham, K.P.; White, Gary C.

    2002-01-01

    Existing models for ring recovery and recapture data analysis treat temporal variations in annual survival probability (S) as fixed effects. Often there is no explainable structure to the temporal variation in S1,..., Sk; random effects can then be a useful model: Si = E(S) + ??i. Here, the temporal variation in survival probability is treated as random with average value E(??2) = ??2. This random effects model can now be fit in program MARK. Resultant inferences include point and interval estimation for process variation, ??2, estimation of E(S) and var (E??(S)) where the latter includes a component for ??2 as well as the traditional component for v??ar(S??\\S??). Furthermore, the random effects model leads to shrinkage estimates, Si, as improved (in mean square error) estimators of Si compared to the MLE, S??i, from the unrestricted time-effects model. Appropriate confidence intervals based on the Si are also provided. In addition, AIC has been generalized to random effects models. This paper presents results of a Monte Carlo evaluation of inference performance under the simple random effects model. Examined by simulation, under the simple one group Cormack-Jolly-Seber (CJS) model, are issues such as bias of ??s2, confidence interval coverage on ??2, coverage and mean square error comparisons for inference about Si based on shrinkage versus maximum likelihood estimators, and performance of AIC model selection over three models: Si ??? S (no effects), Si = E(S) + ??i (random effects), and S1,..., Sk (fixed effects). For the cases simulated, the random effects methods performed well and were uniformly better than fixed effects MLE for the Si.

  13. A survey to assess the provision of conscious sedation by general dental practitioners in the Republic of Ireland.

    PubMed

    Fisher, Veronica; Stassen, Leo F A; Nunn, June

    2011-01-01

    To quantify and qualify how conscious sedation was used in general dental practice before the introduction of formal sedation teaching in the Republic of Ireland. 1. To determine the extent of use of oral, inhalational and intravenous sedation; 2. to determine the training and experience of general dental practitioners providing conscious sedation; 3. to determine the perceived barriers to the practice of conscious sedation; and, 4. to gauge the level of interest in a postgraduate course in conscious sedation. Postal questionnaire sent to one general practitioner in seven, selected randomly from the General Dental Council register, in 2007. Seventy six percent of respondents agreed that the provision of conscious sedation in general dental practice is important. However, the current provision of inhalation and intravenous sedation by respondents is low in comparison to provision in the UK. The main barrier to the use of conscious sedation in general dental practice appears to be lack of availability of training. The data from this study indicated the need for postgraduate training in conscious sedation in Ireland and a need for increased awareness of the Dental Council Code of Practice on sedation.

  14. Physical therapists' perceptions of the roles of the physical therapist assistant.

    PubMed

    Robinson, A J; McCall, M; DePalma, M T; Clayton-Krasinski, D; Tingley, S; Simoncelli, S; Harnish, L

    1994-06-01

    This longitudinal study investigated physical therapists' perceptions of the roles of physical therapist assistants (PTAs). In 1986, a questionnaire describing 79 physical therapy activities was distributed to a random sample (n = 400) of physical therapists derived from the American Physical Therapy Association (APTA) membership. In 1992, a similar questionnaire was distributed to a representative sample (n = 400) of physical therapists derived from the APTA membership. Response rates were 53% and 55% in 1986 and 1992, respectively. Respondents indicated whether each activity was included in the documentation describing PTA roles. Results revealed considerable agreement between therapists' perceptions of PTA roles and those outlined by PTA practice guidelines, and these perceptions changed little over time. Discriminant analyses suggested that therapists' perceptions of PTA roles were, in general, not predicted by supervisory experience with PTAs, therapist experience, or content of entry-level professional education curricula. Generally, therapists' perceptions of PTA roles are consistent with published practice guidelines. Therapists' perceptions on selected activities, however, were incongruent with PTA practice guidelines, suggesting the potential for inefficient or inappropriate utilization of the PTA in the delivery of selected services.

  15. A comparison of a modified sequential oral sensory approach to an applied behavior-analytic approach in the treatment of food selectivity in children with autism spectrum disorder.

    PubMed

    Peterson, Kathryn M; Piazza, Cathleen C; Volkert, Valerie M

    2016-09-01

    Treatments of pediatric feeding disorders based on applied behavior analysis (ABA) have the most empirical support in the research literature (Volkert & Piazza, 2012); however, professionals often recommend, and caregivers often use, treatments that have limited empirical support. In the current investigation, we compared a modified sequential oral sensory approach (M-SOS; Benson, Parke, Gannon, & Muñoz, 2013) to an ABA approach for the treatment of the food selectivity of 6 children with autism. We randomly assigned 3 children to ABA and 3 children to M-SOS and compared the effects of treatment in a multiple baseline design across novel, healthy target foods. We used a multielement design to assess treatment generalization. Consumption of target foods increased for children who received ABA, but not for children who received M-SOS. We subsequently implemented ABA with the children for whom M-SOS was not effective and observed a potential treatment generalization effect during ABA when M-SOS preceded ABA. © 2016 Society for the Experimental Analysis of Behavior.

  16. [Drinking/smoking habits and knowledge regarding heavy drinking/ smoking as a risk factor of stroke among Japanese general population].

    PubMed

    Morimoto, Akiko; Miyamatsu, Naomi; Okamura, Tomonori; Nakayama, Hirohumi; Morinaga, Miho; Toyota, Akihiro; Suzuki, Kazuo; Hata, Takashi; Yamaguchi, Takenori

    2010-10-01

    We examined the knowledge regarding heavy drinking and smoking as risk factors of stroke according to drinking/smoking habits among randomly selected Japanese general population. The Japan Stroke Association and co-researchers have performed a large-scale educational intervention to improve knowledge concerning stroke from 2006 to 2008. Prior to above-mentioned intervention, we conducted mail-surveillance on knowledge about stroke in 11,306 randomly selected residents aged 40 to 74. We assessed the relationship between drinking/smoking habits and knowledge regarding heavy drinking and smoking as risk factors by using the chi-square test and multiple logistic regression analysis adjusting for age, sex, area, employment, living situation, history of stroke and other stroke related diseases, history of liver disease, family history of stroke and drinking (non-drinker / ex-drinker / occasional drinker / habitual drinker) / smoking habits (non-smoker / ex-smoker / current smoker). Total 5,540 subjects (49.0%) participated in this study. Ex-smokers and current smokers had better knowledge regarding smoking as a risk factor of stroke than non-smokers (odds ratio and 95% confidence intervals: 1.89, 1.55-2.31, 1.76, 1.45-2.12, respectively). There was no difference between habitual drinkers and non-drinkers in their knowledge, whereas current smokers had greater knowledge regarding smoking than nonsmokers. Accordingly, it is suggested that it will be necessary for habitual drinkers to be enlightened regarding heavy drinking as a risk factor of stroke and for current smokers to be provided with information regarding not only these risks but also the specific strategies for invoking behavioral changes.

  17. Determination of the optimal number of components in independent components analysis.

    PubMed

    Kassouf, Amine; Jouan-Rimbaud Bouveresse, Delphine; Rutledge, Douglas N

    2018-03-01

    Independent components analysis (ICA) may be considered as one of the most established blind source separation techniques for the treatment of complex data sets in analytical chemistry. Like other similar methods, the determination of the optimal number of latent variables, in this case, independent components (ICs), is a crucial step before any modeling. Therefore, validation methods are required in order to decide about the optimal number of ICs to be used in the computation of the final model. In this paper, three new validation methods are formally presented. The first one, called Random_ICA, is a generalization of the ICA_by_blocks method. Its specificity resides in the random way of splitting the initial data matrix into two blocks, and then repeating this procedure several times, giving a broader perspective for the selection of the optimal number of ICs. The second method, called KMO_ICA_Residuals is based on the computation of the Kaiser-Meyer-Olkin (KMO) index of the transposed residual matrices obtained after progressive extraction of ICs. The third method, called ICA_corr_y, helps to select the optimal number of ICs by computing the correlations between calculated proportions and known physico-chemical information about samples, generally concentrations, or between a source signal known to be present in the mixture and the signals extracted by ICA. These three methods were tested using varied simulated and experimental data sets and compared, when necessary, to ICA_by_blocks. Results were relevant and in line with expected ones, proving the reliability of the three proposed methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Intelligent dental identification system (IDIS) in forensic medicine.

    PubMed

    Chomdej, T; Pankaow, W; Choychumroon, S

    2006-04-20

    This study reports the design and development of the intelligent dental identification system (IDIS), including its efficiency and reliability. Five hundred patients were randomly selected from the Dental Department at Police General Hospital in Thailand to create a population of 3000 known subjects. From the original 500 patients, 100 were randomly selected to create a sample of 1000 unidentifiable subjects (400 subjects with completeness and possible alterations of dental information corresponding to natural occurrences and general dental treatments after the last clinical examination, such as missing teeth, dental caries, dental restorations, and dental prosthetics, 100 subjects with completeness and no alteration of dental information, 500 subjects with incompleteness and no alteration of dental information). Attempts were made to identify the unknown subjects utilizing IDIS. The use of IDIS advanced method resulted in consistent outstanding identification in the range of 82.61-100% with minimal error 0-1.19%. The results of this study indicate that IDIS can be used to support dental identification. It supports not only all types of dentitions: primary, mixed, and permanent but also for incomplete and altered dental information. IDIS is particularly useful in providing the huge quantity and redundancy of related documentation associated with forensic odontology. As a computerized system, IDIS can reduce the time required for identification and store dental digital images with many processing features. Furthermore, IDIS establishes enhancements of documental dental record with odontogram and identification codes, electrical dental record with dental database system, and identification methods and algorithms. IDIS was conceptualized based on the guidelines and standards of the American Board of Forensic Odontology (ABFO) and International Criminal Police Organization (INTERPOL).

  19. The impact of resource quality on the evolution of virulence in spatially heterogeneous environments.

    PubMed

    Su, Min; Boots, Mike

    2017-03-07

    Understanding the drivers of parasite evolution and in particular disease virulence remains a major focus of evolutionary theory. Here, we examine the role of resource quality and in particular spatial environmental heterogeneity in the distribution of these resources on the evolution of virulence. There may be direct effects of resources on host susceptibility and pathogenicity alongside effects on reproduction that indirectly impact host-parasite population dynamics. Therefore, we assume that high resource quality may lead to both increased host reproduction and/or increased disease resistance. In completely mixed populations there is no effect of resource quality on the outcome of disease evolution. However, when there are local interactions higher resource quality generally selects for higher virulence/transmission for both linear and saturating transmission-virulence trade-off assumptions. The exception is that in castrators (i.e., infected hosts have no reproduction), higher virulence is selected for both low and high resource qualities at mixed local and global infection. Heterogeneity in the distribution of environment resources only has an effect on the outcome in castrators where random distributions generally select for higher virulence. Overall, our results further underline the importance of considering spatial structure in order to understand evolutionary processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Image encryption using random sequence generated from generalized information domain

    NASA Astrophysics Data System (ADS)

    Xia-Yan, Zhang; Guo-Ji, Zhang; Xuan, Li; Ya-Zhou, Ren; Jie-Hua, Wu

    2016-05-01

    A novel image encryption method based on the random sequence generated from the generalized information domain and permutation-diffusion architecture is proposed. The random sequence is generated by reconstruction from the generalized information file and discrete trajectory extraction from the data stream. The trajectory address sequence is used to generate a P-box to shuffle the plain image while random sequences are treated as keystreams. A new factor called drift factor is employed to accelerate and enhance the performance of the random sequence generator. An initial value is introduced to make the encryption method an approximately one-time pad. Experimental results show that the random sequences pass the NIST statistical test with a high ratio and extensive analysis demonstrates that the new encryption scheme has superior security.

  1. Estimating the applicability of wound care randomized controlled trials to general wound-care populations by estimating the percentage of individuals excluded from a typical wound-care population in such trials.

    PubMed

    Carter, Marissa J; Fife, Caroline E; Walker, David; Thomson, Brett

    2009-07-01

    To determine the percentage of individuals that would be excluded from wound care randomized controlled trials (RCTs) as a surrogate for applicability to general populations. A representative sample of wound-care RCTs was selected from the literature in the past 10 years. Exclusion criteria from the trials were evaluated, and prevalence values for each excluded condition were obtained from a large wound-care population, as well as from the literature. The percentage of patients excluded on this basis was calculated. Seventeen RCTs testing "high-technology" wound-care products were evaluated. : Patients in the trials were treated for ulcers (venous, diabetic foot, and pressure ulcers). A percentage of patients in the study population were excluded for each RCT. More than 50% of the study population would have been excluded in 15 of the 17 RCTs. When less clinically relevant exclusion criteria were removed, 14 of 17 RCTs would still have excluded between 25% and 50% of the study population. The results raise serious questions regarding the applicability of these RCTs to wound-care populations.

  2. A General Method for Predicting Amino Acid Residues Experiencing Hydrogen Exchange

    PubMed Central

    Wang, Boshen; Perez-Rathke, Alan; Li, Renhao; Liang, Jie

    2018-01-01

    Information on protein hydrogen exchange can help delineate key regions involved in protein-protein interactions and provides important insight towards determining functional roles of genetic variants and their possible mechanisms in disease processes. Previous studies have shown that the degree of hydrogen exchange is affected by hydrogen bond formations, solvent accessibility, proximity to other residues, and experimental conditions. However, a general predictive method for identifying residues capable of hydrogen exchange transferable to a broad set of proteins is lacking. We have developed a machine learning method based on random forest that can predict whether a residue experiences hydrogen exchange. Using data from the Start2Fold database, which contains information on 13,306 residues (3,790 of which experience hydrogen exchange and 9,516 which do not exchange), our method achieves good performance. Specifically, we achieve an overall out-of-bag (OOB) error, an unbiased estimate of the test set error, of 20.3 percent. Using a randomly selected test data set consisting of 500 residues experiencing hydrogen exchange and 500 which do not, our method achieves an accuracy of 0.79, a recall of 0.74, a precision of 0.82, and an F1 score of 0.78.

  3. Dietary approaches to stop hypertension diet and obesity: A cross-sectional study of Iranian children and adolescents.

    PubMed

    Golpour-Hamedani, Sahar; Mohammadifard, Noushin; Khosravi, Alireza; Feizi, Awat; Safavi, Sayyed Morteza

    2017-01-01

    Few studies have investigated the effects of dietary approaches to stop hypertension (DASH) diet on obesity in children. The present study was conducted to examine adherence to the DASH diet in relation to obesity in children and adolescents, Isfahan, Iran. A cross-sectional study was carried out among 456 children aged 11-18 years who were selected by random cluster sampling method. Dietary intakes were assessed using a validated Food Frequency Questionnaire (FFQ). The DASH score was constructed based on food items emphasized or minimized in the DASH diet. Anthropometric measurements were conducted based on standard protocols. General and abdominal obesity were defined based on body mass index ≥ 95th percentiles and waist: height ratio of more than 0.5, respectively. Higher adherence to DASH diet was inversely associated with general obesity (odds ratioT1 vs. T3 3.34, 95% confidence interval 1.28-8.75); however, after controlling for confounding factors, this association disappeared. Furthermore, higher adherence to DASH diet was negatively associated with central obesity in children, but the relation was not statistically significant. We concluded that there was an inverse nonsignificant association between adherence to DASH diet and general obesity indices after adjustment for potential confounders. Further, well-designed randomized clinical trial studies are suggested to find out the effect of DASH diet on obesity obviously.

  4. A Robust and Versatile Method of Combinatorial Chemical Synthesis of Gene Libraries via Hierarchical Assembly of Partially Randomized Modules

    PubMed Central

    Popova, Blagovesta; Schubert, Steffen; Bulla, Ingo; Buchwald, Daniela; Kramer, Wilfried

    2015-01-01

    A major challenge in gene library generation is to guarantee a large functional size and diversity that significantly increases the chances of selecting different functional protein variants. The use of trinucleotides mixtures for controlled randomization results in superior library diversity and offers the ability to specify the type and distribution of the amino acids at each position. Here we describe the generation of a high diversity gene library using tHisF of the hyperthermophile Thermotoga maritima as a scaffold. Combining various rational criteria with contingency, we targeted 26 selected codons of the thisF gene sequence for randomization at a controlled level. We have developed a novel method of creating full-length gene libraries by combinatorial assembly of smaller sub-libraries. Full-length libraries of high diversity can easily be assembled on demand from smaller and much less diverse sub-libraries, which circumvent the notoriously troublesome long-term archivation and repeated proliferation of high diversity ensembles of phages or plasmids. We developed a generally applicable software tool for sequence analysis of mutated gene sequences that provides efficient assistance for analysis of library diversity. Finally, practical utility of the library was demonstrated in principle by assessment of the conformational stability of library members and isolating protein variants with HisF activity from it. Our approach integrates a number of features of nucleic acids synthetic chemistry, biochemistry and molecular genetics to a coherent, flexible and robust method of combinatorial gene synthesis. PMID:26355961

  5. A Robust and Versatile Method of Combinatorial Chemical Synthesis of Gene Libraries via Hierarchical Assembly of Partially Randomized Modules.

    PubMed

    Popova, Blagovesta; Schubert, Steffen; Bulla, Ingo; Buchwald, Daniela; Kramer, Wilfried

    2015-01-01

    A major challenge in gene library generation is to guarantee a large functional size and diversity that significantly increases the chances of selecting different functional protein variants. The use of trinucleotides mixtures for controlled randomization results in superior library diversity and offers the ability to specify the type and distribution of the amino acids at each position. Here we describe the generation of a high diversity gene library using tHisF of the hyperthermophile Thermotoga maritima as a scaffold. Combining various rational criteria with contingency, we targeted 26 selected codons of the thisF gene sequence for randomization at a controlled level. We have developed a novel method of creating full-length gene libraries by combinatorial assembly of smaller sub-libraries. Full-length libraries of high diversity can easily be assembled on demand from smaller and much less diverse sub-libraries, which circumvent the notoriously troublesome long-term archivation and repeated proliferation of high diversity ensembles of phages or plasmids. We developed a generally applicable software tool for sequence analysis of mutated gene sequences that provides efficient assistance for analysis of library diversity. Finally, practical utility of the library was demonstrated in principle by assessment of the conformational stability of library members and isolating protein variants with HisF activity from it. Our approach integrates a number of features of nucleic acids synthetic chemistry, biochemistry and molecular genetics to a coherent, flexible and robust method of combinatorial gene synthesis.

  6. Complex growing networks with intrinsic vertex fitness

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bedogne, C.; Rodgers, G. J.

    2006-10-15

    One of the major questions in complex network research is to identify the range of mechanisms by which a complex network can self organize into a scale-free state. In this paper we investigate the interplay between a fitness linking mechanism and both random and preferential attachment. In our models, each vertex is assigned a fitness x, drawn from a probability distribution {rho}(x). In Model A, at each time step a vertex is added and joined to an existing vertex, selected at random, with probability p and an edge is introduced between vertices with fitnesses x and y, with a ratemore » f(x,y), with probability 1-p. Model B differs from Model A in that, with probability p, edges are added with preferential attachment rather than randomly. The analysis of Model A shows that, for every fixed fitness x, the network's degree distribution decays exponentially. In Model B we recover instead a power-law degree distribution whose exponent depends only on p, and we show how this result can be generalized. The properties of a number of particular networks are examined.« less

  7. Quality of life among untreated sleep apnea patients compared with the general population and changes after treatment with positive airway pressure.

    PubMed

    Bjornsdottir, Erla; Keenan, Brendan T; Eysteinsdottir, Bjorg; Arnardottir, Erna Sif; Janson, Christer; Gislason, Thorarinn; Sigurdsson, Jon Fridrik; Kuna, Samuel T; Pack, Allan I; Benediktsdottir, Bryndis

    2015-06-01

    Obstructive sleep apnea leads to recurrent arousals from sleep, oxygen desaturations, daytime sleepiness and fatigue. This can have an adverse impact on quality of life. The aims of this study were to compare: (i) quality of life between the general population and untreated patients with obstructive sleep apnea; and (ii) changes of quality of life among patients with obstructive sleep apnea after 2 years of positive airway pressure treatment between adherent patients and non-users. Propensity score methodologies were used in order to minimize selection bias and strengthen causal inferences. The enrolled obstructive sleep apnea subjects (n = 822) were newly diagnosed with moderate to severe obstructive sleep apnea who were starting positive airway pressure treatment, and the general population subjects (n = 742) were randomly selected Icelanders. The Short Form 12 was used to measure quality of life. Untreated patients with obstructive sleep apnea had a worse quality of life when compared with the general population. This effect remained significant after using propensity scores to select samples, balanced with regard to age, body mass index, gender, smoking, diabetes, hypertension and cardiovascular disease. We did not find significant overall differences between full and non-users of positive airway pressure in improvement of quality of life from baseline to follow-up. However, there was a trend towards more improvement in physical quality of life for positive airway pressure-adherent patients, and the most obese subjects improved their physical quality of life more. The results suggest that co-morbidities of obstructive sleep apnea, such as obesity, insomnia and daytime sleepiness, have a great effect on life qualities and need to be taken into account and addressed with additional interventions. © 2014 European Sleep Research Society.

  8. First experience with multiple mini interview for medical school admission in Brazil: Does it work in a different cultural scenario?

    PubMed

    Daniel-Filho, Durval Anibal; Pires, Elda Maria Stafuzza Gonçalves; Paes, Angela Tavares; Troster, Eduardo Juan; Silva, Simone Cristina Azevedo B S; Granato, Mariana Fachini; Couto, Thomaz Bittencourt; Barreto, Joyce Kelly Silva; Campos, Alexandre Holthausen; Monte, Julio C Martins; Schvartsman, Claudio

    2017-10-01

    Evaluation of non-cognitive skills never has been used in Brazil. This study aims to evaluate Multiple Mini Interviews (MMI) in the admission process of a School of Medicine in São Paulo, Brazil. The population of the study comprised 240 applicants summoned for the interviews, and 96 raters. MMI contributed to 25% of the applicants' final grade. Eight scenarios were created with the aim of evaluating different non-cognitive skills, each one had two raters. At the end of the interviews, the applicants and raters described their impressions about MMI. The reliability of the MMI was analyzed using the Theory of Generalization and Many-Facet Rasch Model (MFRM). The G-study showed that the general reliability of the process was satisfactory (coefficient G = 0.743). The MMI grades were not affected by the raters' profile, time of interview (p = 0.715), and randomization group (p = 0.353). The Rasch analysis showed that there was no misfitting effects or inconsistent stations or raters. A significant majority of the applicants (98%) and all the raters believed MMIs were important in selecting students with a more adequate profile to study medicine. The general reliability of the selection process was excellent, and it was fully accepted by the applicants and raters.

  9. 40 CFR 761.355 - Third level of sample selection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...

  10. 40 CFR 761.355 - Third level of sample selection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...

  11. 40 CFR 761.355 - Third level of sample selection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...

  12. 40 CFR 761.355 - Third level of sample selection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...

  13. 40 CFR 761.355 - Third level of sample selection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of sample selection further reduces the size of the subsample to 100 grams which is suitable for the... procedures in § 761.353 of this part into 100 gram portions. (b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate...

  14. Influence of stochastic geometric imperfections on the load-carrying behaviour of thin-walled structures using constrained random fields

    NASA Astrophysics Data System (ADS)

    Lauterbach, S.; Fina, M.; Wagner, W.

    2018-04-01

    Since structural engineering requires highly developed and optimized structures, the thickness dependency is one of the most controversially debated topics. This paper deals with stability analysis of lightweight thin structures combined with arbitrary geometrical imperfections. Generally known design guidelines only consider imperfections for simple shapes and loading, whereas for complex structures the lower-bound design philosophy still holds. Herein, uncertainties are considered with an empirical knockdown factor representing a lower bound of existing measurements. To fully understand and predict expected bearable loads, numerical investigations are essential, including geometrical imperfections. These are implemented into a stand-alone program code with a stochastic approach to compute random fields as geometric imperfections that are applied to nodes of the finite element mesh of selected structural examples. The stochastic approach uses the Karhunen-Loève expansion for the random field discretization. For this approach, the so-called correlation length l_c controls the random field in a powerful way. This parameter has a major influence on the buckling shape, and also on the stability load. First, the impact of the correlation length is studied for simple structures. Second, since most structures for engineering devices are more complex and combined structures, these are intensively discussed with the focus on constrained random fields for e.g. flange-web-intersections. Specific constraints for those random fields are pointed out with regard to the finite element model. Further, geometrical imperfections vanish where the structure is supported.

  15. Peculiarities of the statistics of spectrally selected fluorescence radiation in laser-pumped dye-doped random media

    NASA Astrophysics Data System (ADS)

    Yuvchenko, S. A.; Ushakova, E. V.; Pavlova, M. V.; Alonova, M. V.; Zimnyakov, D. A.

    2018-04-01

    We consider the practical realization of a new optical probe method of the random media which is defined as the reference-free path length interferometry with the intensity moments analysis. A peculiarity in the statistics of the spectrally selected fluorescence radiation in laser-pumped dye-doped random medium is discussed. Previously established correlations between the second- and the third-order moments of the intensity fluctuations in the random interference patterns, the coherence function of the probe radiation, and the path difference probability density for the interfering partial waves in the medium are confirmed. The correlations were verified using the statistical analysis of the spectrally selected fluorescence radiation emitted by a laser-pumped dye-doped random medium. Water solution of Rhodamine 6G was applied as the doping fluorescent agent for the ensembles of the densely packed silica grains, which were pumped by the 532 nm radiation of a solid state laser. The spectrum of the mean path length for a random medium was reconstructed.

  16. Assessment of healthcare professionals' knowledge about warfarin-vitamin K drug-nutrient interactions.

    PubMed

    Couris, R R; Tataronis, G R; Dallal, G E; Blumberg, J B; Dwyer, J T

    2000-08-01

    Dietary vitamin K can interact with oral anticoagulant drugs and interfere with their therapeutic safety and efficacy. Therefore, knowledge about drug-nutrient interactions involving vitamin K possessed by physicians, pharmacists, dietitians and nurses practicing anticoagulant therapy was assessed. Healthcare practitioners were surveyed using a 30-question, 98-item questionnaire on the most common and/or important food interactions with warfarin, drug interactions with warfarin and general drug-nutrient interactions involving vitamin K. The study sample included 160 randomly selected healthcare providers (40 physicians, pharmacists, dietitians and nurses) from 10 hospitals with 200 to 1000 beds from six Massachusetts regions. Random selection was conducted from a pool of selected healthcare providers practicing anticoagulant therapy who counsel patients receiving warfarin. All surveys were completed within three months of the start of the study, and all participants provided usable data for statistical analysis. The mean scores (+/- SD) on the overall test were 72.5+/-9.0 for pharmacists, 62.51+/-10.6 for physicians, 56.9+/-8.8 for dietitians and 50.2+/-9.3 for nurses, with 100 being a perfect score. Pharmacists scored significantly higher in the area of drug interactions (75.9+/-11.3, p<0.05). Dietitians scored higher in the area of food interactions (73.0+/-10.3). No significant differences between physicians and pharmacists were evident on general drug-nutrient interactions. While over 87% of the healthcare professionals correctly identified some common foods containing large amounts of vitamin K, such as broccoli and spinach, fewer than 25% were able to identify others such as pea soup, coleslaw and dill pickles. Although the healthcare professionals surveyed in this study appear to have demonstrated some proficiency in their respective areas of expertise, they exhibited less knowledge in others. Therefore, additional training and integration of knowledge and expertise about drug-nutrient interactions among healthcare professionals are essential to provide appropriate patient counseling and optimal therapeutic outcomes.

  17. Results from six generations of selection for intramuscular fat in Duroc swine using real-time ultrasound. II. Genetic parameters and trends.

    PubMed

    Schwab, C R; Baas, T J; Stalder, K J

    2010-01-01

    Design of breeding programs requires knowledge of variance components that exist for traits included in specific breeding goals and the genetic relationships that exist among traits of economic importance. A study was conducted to evaluate direct and correlated genetic responses to selection for intramuscular fat (IMF) and to estimate genetic parameters for economically important traits in Duroc swine. Forty gilts were purchased from US breeders and randomly mated for 2 generations to boars available in regional boar studs to develop a base population of 56 litters. Littermate pairs of gilts from this population were randomly assigned to a select line (SL) or control line (CL) and mated to the same boar to establish genetic ties between lines. In the SL, the top 10 boars and 75 gilts were selected based on IMF EBV obtained from a bivariate animal model that included IMF evaluated on the carcass and IMF predicted via ultrasound. One boar from each sire family and 50 to 60 gilts representing all sire families were randomly selected to maintain the CL. Carcass and ultrasound IMF were both moderately heritable (0.31 and 0.38, respectively). Moderate to high genetic relationships were estimated among carcass backfat and meat quality measures of IMF, Instron tenderness, and objective loin muscle color. Based on estimates obtained in this study, more desirable genetic merit for pH is associated with greater genetic value for loin color, tenderness, and sensory characteristics. Intramuscular fat measures obtained on the carcass and predicted using ultrasound technology were highly correlated (r(g) = 0.86 from a 12-trait analysis; r(g) = 0.90 from a 5-trait analysis). Estimated genetic relationships among IMF measures and other traits evaluated were generally consistent. Intramuscular fat measures were also genetically associated with Instron tenderness and flavor score in a desirable direction. Direct genetic response in IMF measures observed in the SL corresponded to a significant decrease in EBV for carcass loin muscle area (-0.90 cm(2) per generation) and an increase in carcass backfat EBV (0.98 mm per generation). Selection for IMF has led to more desirable EBV for objective tenderness and has had an adverse effect on additive genetic merit for objective loin color.

  18. Design of the Blood Pressure Goals in Dialysis pilot study.

    PubMed

    Gul, Ambreen; Miskulin, Dana; Gassman, Jennifer; Harford, Antonia; Horowitz, Bruce; Chen, Joline; Paine, Susan; Bedrick, Edward; Kusek, John W; Unruh, Mark; Zager, Philip

    2014-02-01

    Cardiovascular disease (CVD) is markedly increased among hemodialysis (HD) patients. Optimizing blood pressure (BP) among HD patients may present an important opportunity to reduce the disparity in CVD rates between HD patients and the general population. The optimal target predialysis systolic BP (SBP) among HD patients is unknown. Current international guidelines, calling for a predialysis SBP < 140 mm Hg, are based on the opinion and extrapolation from the general population. Existing randomized controlled trials (RCTs) were small and did not include prespecified BP targets. The authors described the design of the Blood Pressure in Dialysis (BID) Study, a pilot, multicenter RCT where HD patients are randomized to either a target-standardized predialysis SBP of 110 to 140 mm Hg or 155 to 165 mm Hg. This is the first study to randomize HD patients to 2 different SBP targets. Primary outcomes are feasibility and safety. Feasibility parameters include recruitment and retention rates, adherence with prescribed BP measurements and achievement and maintenance of selected BP targets. Safety parameters include rates of hypotension and other adverse and serious adverse events. The authors obtained preliminary data on changes in left ventricular mass, aortic pulse wave velocity, vascular access thromboses and health-related quality of life across study arms, which may be the secondary outcomes in the full-scale study. The data acquired in the pilot RCT will determine the feasibility and safety and inform the design of a full-scale trial, powered for hard outcomes, which may require 2000 participants.

  19. Strength and Jump Biomechanics of Elite and Recreational Female Youth Soccer Players

    PubMed Central

    Chrisman, Sara P.; O'Kane, John W.; Polissar, Nayak L.; Tencer, Allan F.; Mack, Christopher D.; Levy, Marni R.; Schiff, Melissa A.

    2012-01-01

    Context Most researchers investigating soccer injuries have studied elite athletes because they have greater athletic-exposure hours than other athletes, but most youth participate at the recreational level. If risk factors for injury vary by soccer level, then recommendations generated using research with elite youth soccer players might not generalize to recreational players. Objective To examine injury risk factors of strength and jump biomechanics by soccer level in female youth athletes and to determine whether research recommendations based on elite youth athletes could be generalized to recreational players. Design Cross-sectional study. Setting Seattle Youth Soccer Association. Patients or Other Participants Female soccer players (N = 92) aged 11 to 14 years were recruited from 4 randomly selected elite (n = 50; age = 12.5 years, 95% confidence interval [95% CI]) = 12.3, 12.8 years; height = 157.8 cm, 95% CI = 155.2, 160.3 cm; mass = 49.9 kg, 95% CI = 47.3, 52.6 kg) and 4 randomly selected recreational (n = 42; age = 13.2 years, 95% CI = 13.0, 13.5 years; height = 161.1 cm, 95% CI = 159.2, 163.1 cm; mass = 50.6 kg, 95% CI = 48.3, 53.0 kg) soccer teams. Main Outcome Measure(s) Players completed a questionnaire about demographics, history of previous injury, and soccer experience. Physical therapists used dynamometry to measure hip strength (abduction, adduction, extension, flexion) and knee strength (flexion, extension) and Sportsmetrics to measure vertical jump height and jump biomechanics. We compared all measurements by soccer level using linear regression to adjust for age and mass. Results Elite players were similar to recreational players in all measures of hip and knee strength, vertical jump height, and normalized knee separation (a valgus estimate generated using Sportsmetrics). Conclusions Female elite youth players and recreational players had similar lower extremity strength and jump biomechanics. This suggests that recommendations generated from research with elite youth soccer players could be generalized to recreational players. PMID:23182007

  20. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair.

    PubMed

    Chang, Zhiwei; Halle, Bertil

    2013-10-14

    In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water (1)H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft-tissue contrast in clinical magnetic resonance imaging.

  1. A meta-analysis of lesser prairie-chicken nesting and brood-rearing habitats: implications for habitat management

    USGS Publications Warehouse

    Hagen, Christian A.; Grisham, Blake A.; Boal, Clint W.; Haukos, David A.

    2013-01-01

    The distribution and range of lesser prairie-chicken (Tympanuchus pallidicinctus) has been reduced by >90% since European settlement of the Great Plains of North America. Currently, lesser prairie-chickens occupy 3 general vegetation communities: sand sagebrush (Artemisia filifolia), sand shinnery oak (Quercus havardii), and mixed-grass prairies juxtaposed with Conservation Reserve Program grasslands. As a candidate for protection under the Endangered Species Act, there is a need for a synthesis that characterizes habitat structure rangewide. Thus, we conducted a meta-analysis of vegetation characteristics at nest sites and brood habitats to determine whether there was an overall effect (Hedges' d) of habitat selection and to estimate average (95% CI) habitat characteristics at use sites. We estimated effect sizes (di) from the difference between use (nests and brood sites) and random sampling sites for each study (n = 14), and derived an overall effect size (d++). There was a general effect for habitat selection as evidenced by low levels of variation in effect sizes across studies and regions. There was a small to medium effect (d++) = 0.20-0.82) of selection for greater vertical structure (visual obstruction) by nesting females in both vegetation communities, and selection against bare ground (d++ = 0.20-0.58). Females with broods exhibited less selectivity for habitat components except for vertical structure. The variation of d++ was greater during nesting than brooding periods, signifying a seasonal shift in habitat use, and perhaps a greater range of tolerance for brood-rearing habitat. The overall estimates of vegetation cover were consistent with those provided in management guidelines for the species.

  2. Selecting the Best: Evolutionary Engineering of Chemical Production in Microbes.

    PubMed

    Shepelin, Denis; Hansen, Anne Sofie Lærke; Lennen, Rebecca; Luo, Hao; Herrgård, Markus J

    2018-05-11

    Microbial cell factories have proven to be an economical means of production for many bulk, specialty, and fine chemical products. However, we still lack both a holistic understanding of organism physiology and the ability to predictively tune enzyme activities in vivo, thus slowing down rational engineering of industrially relevant strains. An alternative concept to rational engineering is to use evolution as the driving force to select for desired changes, an approach often described as evolutionary engineering. In evolutionary engineering, in vivo selections for a desired phenotype are combined with either generation of spontaneous mutations or some form of targeted or random mutagenesis. Evolutionary engineering has been used to successfully engineer easily selectable phenotypes, such as utilization of a suboptimal nutrient source or tolerance to inhibitory substrates or products. In this review, we focus primarily on a more challenging problem-the use of evolutionary engineering for improving the production of chemicals in microbes directly. We describe recent developments in evolutionary engineering strategies, in general, and discuss, in detail, case studies where production of a chemical has been successfully achieved through evolutionary engineering by coupling production to cellular growth.

  3. Variable selection in subdistribution hazard frailty models with competing risks data

    PubMed Central

    Do Ha, Il; Lee, Minjung; Oh, Seungyoung; Jeong, Jong-Hyeon; Sylvester, Richard; Lee, Youngjo

    2014-01-01

    The proportional subdistribution hazards model (i.e. Fine-Gray model) has been widely used for analyzing univariate competing risks data. Recently, this model has been extended to clustered competing risks data via frailty. To the best of our knowledge, however, there has been no literature on variable selection method for such competing risks frailty models. In this paper, we propose a simple but unified procedure via a penalized h-likelihood (HL) for variable selection of fixed effects in a general class of subdistribution hazard frailty models, in which random effects may be shared or correlated. We consider three penalty functions (LASSO, SCAD and HL) in our variable selection procedure. We show that the proposed method can be easily implemented using a slight modification to existing h-likelihood estimation approaches. Numerical studies demonstrate that the proposed procedure using the HL penalty performs well, providing a higher probability of choosing the true model than LASSO and SCAD methods without losing prediction accuracy. The usefulness of the new method is illustrated using two actual data sets from multi-center clinical trials. PMID:25042872

  4. Improving the self-efficacy of teachers in schools: results of health promotion program.

    PubMed

    Farokhzadian, Jamileh; Sabzi, Amirreza; Mangolian Shahrbabaki, Parvin

    2018-06-12

    Background In order to effectively facilitate behavior change, it is essential to conduct health promotion programs on self-efficacy. Given the importance of the role of teachers in fostering the next generation, it appears that the promotion of self-efficacy in them can greatly contribute to the health of the community. The present study aimed to evaluate the impact of a health promotion training workshop on self-efficacy for health practices and also, on general self-efficacy of teachers in schools. Methods This study was a quasi-experimental study, in which 120 teachers were selected by random sampling and randomly divided into two equal intervention and control groups (60 in each group). A health promotion training workshop was conducted for the intervention group. Data were collected by a three-section questionnaire (demographic, self-rated ability for health practices scale and general self-efficacy) before and 1 month after the training intervention. Results The self-efficacy scores for health practices and general self-efficacy were not significantly different between the intervention and control groups before the intervention (p > 0.05). However, participants in the intervention group reported higher scores on both the self-efficacy for health practices (t = 4.05, p = 0.001) and general self-efficacy (t = 2.92, p = 0.004) compared to those in the control group one month after the intervention. Conclusion The health promotion training program had improving effects on the self-efficacy for health practices and general self-efficacy. This program was potentially a valid community health nursing intervention that can be presented and evaluated in various community settings.

  5. Advanced reliability methods for structural evaluation

    NASA Technical Reports Server (NTRS)

    Wirsching, P. H.; Wu, Y.-T.

    1985-01-01

    Fast probability integration (FPI) methods, which can yield approximate solutions to such general structural reliability problems as the computation of the probabilities of complicated functions of random variables, are known to require one-tenth the computer time of Monte Carlo methods for a probability level of 0.001; lower probabilities yield even more dramatic differences. A strategy is presented in which a computer routine is run k times with selected perturbed values of the variables to obtain k solutions for a response variable Y. An approximating polynomial is fit to the k 'data' sets, and FPI methods are employed for this explicit form.

  6. Metastatic Ewing's Sarcoma: Revisiting the “Evidence on the Fence”

    PubMed Central

    Khanna, Nehal; Pandey, Avinash; Bajpai, Jyoti

    2017-01-01

    Metastatic Ewing's sarcoma is a challenging disease for oncology care providers with wide spectrum of disease at presentation, widely varying approach to the treatment and varied outcomes. The paucity of randomized evidence is a barrier in developing a consensus. This perspective provides the evidence ”for and against” the benefit of aggressive approach including local and systemic therapy in patients presenting with metastatic Ewing's sarcoma and provide general recommendations so as to help select patients who will benefit with definitive intent treatment and also, avoid aggressive approach in patients with dismal outcome. PMID:28900327

  7. THE SELECTION OF A NATIONAL RANDOM SAMPLE OF TEACHERS FOR EXPERIMENTAL CURRICULUM EVALUATION.

    ERIC Educational Resources Information Center

    WELCH, WAYNE W.; AND OTHERS

    MEMBERS OF THE EVALUATION SECTION OF HARVARD PROJECT PHYSICS, DESCRIBING WHAT IS SAID TO BE THE FIRST ATTEMPT TO SELECT A NATIONAL RANDOM SAMPLE OF (HIGH SCHOOL PHYSICS) TEACHERS, LIST THE STEPS AS (1) PURCHASE OF A LIST OF PHYSICS TEACHERS FROM THE NATIONAL SCIENCE TEACHERS ASSOCIATION (MOST COMPLETE AVAILABLE), (2) SELECTION OF 136 NAMES BY A…

  8. Statistical models for estimating daily streamflow in Michigan

    USGS Publications Warehouse

    Holtschlag, D.J.; Salehi, Habib

    1992-01-01

    Statistical models for estimating daily streamflow were analyzed for 25 pairs of streamflow-gaging stations in Michigan. Stations were paired by randomly choosing a station operated in 1989 at which 10 or more years of continuous flow data had been collected and at which flow is virtually unregulated; a nearby station was chosen where flow characteristics are similar. Streamflow data from the 25 randomly selected stations were used as the response variables; streamflow data at the nearby stations were used to generate a set of explanatory variables. Ordinary-least squares regression (OLSR) equations, autoregressive integrated moving-average (ARIMA) equations, and transfer function-noise (TFN) equations were developed to estimate the log transform of flow for the 25 randomly selected stations. The precision of each type of equation was evaluated on the basis of the standard deviation of the estimation errors. OLSR equations produce one set of estimation errors; ARIMA and TFN models each produce l sets of estimation errors corresponding to the forecast lead. The lead-l forecast is the estimate of flow l days ahead of the most recent streamflow used as a response variable in the estimation. In this analysis, the standard deviation of lead l ARIMA and TFN forecast errors were generally lower than the standard deviation of OLSR errors for l < 2 days and l < 9 days, respectively. Composite estimates were computed as a weighted average of forecasts based on TFN equations and backcasts (forecasts of the reverse-ordered series) based on ARIMA equations. The standard deviation of composite errors varied throughout the length of the estimation interval and generally was at maximum near the center of the interval. For comparison with OLSR errors, the mean standard deviation of composite errors were computed for intervals of length 1 to 40 days. The mean standard deviation of length-l composite errors were generally less than the standard deviation of the OLSR errors for l < 32 days. In addition, the composite estimates ensure a gradual transition between periods of estimated and measured flows. Model performance among stations of differing model error magnitudes were compared by computing ratios of the mean standard deviation of the length l composite errors to the standard deviation of OLSR errors. The mean error ratio for the set of 25 selected stations was less than 1 for intervals l < 32 days. Considering the frequency characteristics of the length of intervals of estimated record in Michigan, the effective mean error ratio for intervals < 30 days was 0.52. Thus, for intervals of estimation of 1 month or less, the error of the composite estimate is substantially lower than error of the OLSR estimate.

  9. On the Wigner law in dilute random matrices

    NASA Astrophysics Data System (ADS)

    Khorunzhy, A.; Rodgers, G. J.

    1998-12-01

    We consider ensembles of N × N symmetric matrices whose entries are weakly dependent random variables. We show that random dilution can change the limiting eigenvalue distribution of such matrices. We prove that under general and natural conditions the normalised eigenvalue counting function coincides with the semicircle (Wigner) distribution in the limit N → ∞. This can be explained by the observation that dilution (or more generally, random modulation) eliminates the weak dependence (or correlations) between random matrix entries. It also supports our earlier conjecture that the Wigner distribution is stable to random dilution and modulation.

  10. Unbiased feature selection in learning random forests for high-dimensional data.

    PubMed

    Nguyen, Thanh-Tung; Huang, Joshua Zhexue; Nguyen, Thuy Thi

    2015-01-01

    Random forests (RFs) have been widely used as a powerful classification method. However, with the randomization in both bagging samples and feature selection, the trees in the forest tend to select uninformative features for node splitting. This makes RFs have poor accuracy when working with high-dimensional data. Besides that, RFs have bias in the feature selection process where multivalued features are favored. Aiming at debiasing feature selection in RFs, we propose a new RF algorithm, called xRF, to select good features in learning RFs for high-dimensional data. We first remove the uninformative features using p-value assessment, and the subset of unbiased features is then selected based on some statistical measures. This feature subset is then partitioned into two subsets. A feature weighting sampling technique is used to sample features from these two subsets for building trees. This approach enables one to generate more accurate trees, while allowing one to reduce dimensionality and the amount of data needed for learning RFs. An extensive set of experiments has been conducted on 47 high-dimensional real-world datasets including image datasets. The experimental results have shown that RFs with the proposed approach outperformed the existing random forests in increasing the accuracy and the AUC measures.

  11. Regional or general anesthesia for fast-track hip and knee replacement - what is the evidence?

    PubMed Central

    Kehlet, Henrik; Aasvang, Eske Kvanner

    2015-01-01

    Regional anesthesia for knee and hip arthroplasty may have favorable outcome effects compared with general anesthesia by effectively blocking afferent input, providing initial postoperative analgesia, reducing endocrine metabolic responses, and providing sympathetic blockade with reduced bleeding and less risk of thromboembolic complications but with undesirable effects on lower limb motor and urinary bladder function. Old randomized studies supported the use of regional anesthesia with fewer postoperative pulmonary and thromboembolic complications, and this has been supported by recent large non-randomized epidemiological database cohort studies. In contrast, the data from newer randomized trials are conflicting, and recent studies using modern general anesthetic techniques may potentially support the use of general versus spinal anesthesia. In summary, the lack of properly designed large randomized controlled trials comparing modern general anesthesia and spinal anesthesia for knee and hip arthroplasty prevents final recommendations and calls for prospective detailed studies in this clinically important field. PMID:26918127

  12. Applications of random forest feature selection for fine-scale genetic population assignment.

    PubMed

    Sylvester, Emma V A; Bentzen, Paul; Bradbury, Ian R; Clément, Marie; Pearce, Jon; Horne, John; Beiko, Robert G

    2018-02-01

    Genetic population assignment used to inform wildlife management and conservation efforts requires panels of highly informative genetic markers and sensitive assignment tests. We explored the utility of machine-learning algorithms (random forest, regularized random forest and guided regularized random forest) compared with F ST ranking for selection of single nucleotide polymorphisms (SNP) for fine-scale population assignment. We applied these methods to an unpublished SNP data set for Atlantic salmon ( Salmo salar ) and a published SNP data set for Alaskan Chinook salmon ( Oncorhynchus tshawytscha ). In each species, we identified the minimum panel size required to obtain a self-assignment accuracy of at least 90% using each method to create panels of 50-700 markers Panels of SNPs identified using random forest-based methods performed up to 7.8 and 11.2 percentage points better than F ST -selected panels of similar size for the Atlantic salmon and Chinook salmon data, respectively. Self-assignment accuracy ≥90% was obtained with panels of 670 and 384 SNPs for each data set, respectively, a level of accuracy never reached for these species using F ST -selected panels. Our results demonstrate a role for machine-learning approaches in marker selection across large genomic data sets to improve assignment for management and conservation of exploited populations.

  13. High-Tg Polynorbornene-Based Block and Random Copolymers for Butanol Pervaporation Membranes

    NASA Astrophysics Data System (ADS)

    Register, Richard A.; Kim, Dong-Gyun; Takigawa, Tamami; Kashino, Tomomasa; Burtovyy, Oleksandr; Bell, Andrew

    Vinyl addition polymers of substituted norbornene (NB) monomers possess desirably high glass transition temperatures (Tg); however, until very recently, the lack of an applicable living polymerization chemistry has precluded the synthesis of such polymers with controlled architecture, or copolymers with controlled sequence distribution. We have recently synthesized block and random copolymers of NB monomers bearing hydroxyhexafluoroisopropyl and n-butyl substituents (HFANB and BuNB) via living vinyl addition polymerization with Pd-based catalysts. Both series of polymers were cast into the selective skin layers of thin film composite (TFC) membranes, and these organophilic membranes investigated for the isolation of n-butanol from dilute aqueous solution (model fermentation broth) via pervaporation. The block copolymers show well-defined microphase-separated morphologies, both in bulk and as the selective skin layers on TFC membranes, while the random copolymers are homogeneous. Both block and random vinyl addition copolymers are effective as n-butanol pervaporation membranes, with the block copolymers showing a better flux-selectivity balance. While polyHFANB has much higher permeability and n-butanol selectivity than polyBuNB, incorporating BuNB units into the polymer (in either a block or random sequence) limits the swelling of the polyHFANB and thereby improves the n-butanol pervaporation selectivity.

  14. Predicting the continuum between corridors and barriers to animal movements using Step Selection Functions and Randomized Shortest Paths.

    PubMed

    Panzacchi, Manuela; Van Moorter, Bram; Strand, Olav; Saerens, Marco; Kivimäki, Ilkka; St Clair, Colleen C; Herfindal, Ivar; Boitani, Luigi

    2016-01-01

    The loss, fragmentation and degradation of habitat everywhere on Earth prompts increasing attention to identifying landscape features that support animal movement (corridors) or impedes it (barriers). Most algorithms used to predict corridors assume that animals move through preferred habitat either optimally (e.g. least cost path) or as random walkers (e.g. current models), but neither extreme is realistic. We propose that corridors and barriers are two sides of the same coin and that animals experience landscapes as spatiotemporally dynamic corridor-barrier continua connecting (separating) functional areas where individuals fulfil specific ecological processes. Based on this conceptual framework, we propose a novel methodological approach that uses high-resolution individual-based movement data to predict corridor-barrier continua with increased realism. Our approach consists of two innovations. First, we use step selection functions (SSF) to predict friction maps quantifying corridor-barrier continua for tactical steps between consecutive locations. Secondly, we introduce to movement ecology the randomized shortest path algorithm (RSP) which operates on friction maps to predict the corridor-barrier continuum for strategic movements between functional areas. By modulating the parameter Ѳ, which controls the trade-off between exploration and optimal exploitation of the environment, RSP bridges the gap between algorithms assuming optimal movements (when Ѳ approaches infinity, RSP is equivalent to LCP) or random walk (when Ѳ → 0, RSP → current models). Using this approach, we identify migration corridors for GPS-monitored wild reindeer (Rangifer t. tarandus) in Norway. We demonstrate that reindeer movement is best predicted by an intermediate value of Ѳ, indicative of a movement trade-off between optimization and exploration. Model calibration allows identification of a corridor-barrier continuum that closely fits empirical data and demonstrates that RSP outperforms models that assume either optimality or random walk. The proposed approach models the multiscale cognitive maps by which animals likely navigate real landscapes and generalizes the most common algorithms for identifying corridors. Because suboptimal, but non-random, movement strategies are likely widespread, our approach has the potential to predict more realistic corridor-barrier continua for a wide range of species. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  15. Cumulative Evidence of Randomized Controlled and Observational Studies on Catheter-Related Infection Risk of Central Venous Catheter Insertion Site in ICU Patients: A Pairwise and Network Meta-Analysis.

    PubMed

    Arvaniti, Kostoula; Lathyris, Dimitrios; Blot, Stijn; Apostolidou-Kiouti, Fani; Koulenti, Despoina; Haidich, Anna-Bettina

    2017-04-01

    Selection of central venous catheter insertion site in ICU patients could help reduce catheter-related infections. Although subclavian was considered the most appropriate site, its preferential use in ICU patients is not generalized and questioned by contradicted meta-analysis results. In addition, conflicting data exist on alternative site selection whenever subclavian is contraindicated. To compare catheter-related bloodstream infection and colonization risk between the three sites (subclavian, internal jugular, and femoral) in adult ICU patients. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled trials, CINAHL, and ClinicalTrials.gov. Eligible studies were randomized controlled trials and observational ones. Extracted data were analyzed by pairwise and network meta-analysis. Twenty studies were included; 11 were observational, seven were randomized controlled trials for other outcomes, and two were randomized controlled trials for sites. We evaluated 18,554 central venous catheters: 9,331 from observational studies, 5,482 from randomized controlled trials for other outcomes, and 3,741 from randomized controlled trials for sites. Colonization risk was higher for internal jugular (relative risk, 2.25 [95% CI, 1.84-2.75]; I = 0%) and femoral (relative risk, 2.92 [95% CI, 2.11-4.04]; I = 24%), compared with subclavian. Catheter-related bloodstream infection risk was comparable for internal jugular and subclavian, higher for femoral than subclavian (relative risk, 2.44 [95% CI, 1.25-4.75]; I = 61%), and lower for internal jugular than femoral (relative risk, 0.55 [95% CI, 0.34-0.89]; I = 61%). When observational studies that did not control for baseline characteristics were excluded, catheter-related bloodstream infection risk was comparable between the sites. In ICU patients, internal jugular and subclavian may, similarly, decrease catheter-related bloodstream infection risk, when compared with femoral. Subclavian could be suggested as the most appropriate site, whenever colonization risk is considered and not, otherwise, contraindicated. Current evidence on catheter-related bloodstream infection femoral risk, compared with the other sites, is inconclusive.

  16. Neutrality and evolvability of designed protein sequences

    NASA Astrophysics Data System (ADS)

    Bhattacherjee, Arnab; Biswas, Parbati

    2010-07-01

    The effect of foldability on protein’s evolvability is analyzed by a two-prong approach consisting of a self-consistent mean-field theory and Monte Carlo simulations. Theory and simulation models representing protein sequences with binary patterning of amino acid residues compatible with a particular foldability criteria are used. This generalized foldability criterion is derived using the high temperature cumulant expansion approximating the free energy of folding. The effect of cumulative point mutations on these designed proteins is studied under neutral condition. The robustness, protein’s ability to tolerate random point mutations is determined with a selective pressure of stability (ΔΔG) for the theory designed sequences, which are found to be more robust than that of Monte Carlo and mean-field-biased Monte Carlo generated sequences. The results show that this foldability criterion selects viable protein sequences more effectively compared to the Monte Carlo method, which has a marked effect on how the selective pressure shapes the evolutionary sequence space. These observations may impact de novo sequence design and its applications in protein engineering.

  17. Aloe vera herbal dentifrices for plaque and gingivitis control: a systematic review.

    PubMed

    Dhingra, K

    2014-04-01

    To evaluate the effectiveness of aloe vera containing herbal dentifrices in improving plaque control and gingival health. A manual and electronic literature (MEDLINE and Cochrane Central Register of Controlled Trials) search was performed up to July 2012, for randomized controlled trials presenting clinical, microbiological, immunological, and patient-centered data for the efficacy of aloe vera herbal dentifrices for controlling plaque and gingival inflammation in patients with gingivitis. From 79 titles and abstracts, eight full-text articles were screened and finally two randomized controlled trials were selected. These randomized controlled trials reported that aloe vera dentifrices were similar in efficacy to control dentifrices in effectively reducing plaque and gingival inflammation in gingivitis patients based on the assessment of clinical, microbiological, and patient-centered treatment outcomes. However, many important details (composition and characteristics of aloe vera and control dentifrices along with appropriate randomization, blinding, and outcomes assessed) were lacking in these trials, and therefore, the quality of reporting and methods was generally flawed with high risk of bias. Even though there are some promising results, the clinical effectiveness of aloe vera herbal dentifrices is not sufficiently defined at present and warrants further investigations based on reporting guidelines of herbal CONSORT statement. © 2013 John Wiley & Sons A/S.

  18. Robust portfolio selection based on asymmetric measures of variability of stock returns

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Tan, Shaohua

    2009-10-01

    This paper addresses a new uncertainty set--interval random uncertainty set for robust optimization. The form of interval random uncertainty set makes it suitable for capturing the downside and upside deviations of real-world data. These deviation measures capture distributional asymmetry and lead to better optimization results. We also apply our interval random chance-constrained programming to robust mean-variance portfolio selection under interval random uncertainty sets in the elements of mean vector and covariance matrix. Numerical experiments with real market data indicate that our approach results in better portfolio performance.

  19. The relationship between general health and coping style with the perceived stress in primigravida healthy pregnant women: using the PATH model.

    PubMed

    Shamsaei, Farshid; Maleki, Azam; Shobeiri, Fatemeh; Soltani, Farzaneh; Ahmadi, Fazlollah; Roshanaei, Ghodratollah

    2018-02-05

    The aim of this study was to analyze relationships among general health, coping style, and perceived stress in healthy primigravida pregnant women. A cross-sectional study was conducted at public health clinics in Hamadan city, Iran between July and December 2015. In total, 380 pregnant women were selected through stratified random sampling. Data were collected using the Revised Prenatal Coping Inventory and General Health Questionnaire. Perceived stress was assessed through an interview comprised of open-ended questions. The final PATH model fit well; general health (β = 0.02) as well as anxiety and sleep disorders (β = 0.03) were slightly directly associated with perceived stress, and only planning-preparation was related to perceived stress through general health (β = 0.09). The findings enhance the knowledge gained from previous perinatal stress research. General health status was directly related to stress, and coping style was indirectly related to stress. Coping styles may mediate the relationship between general health status and perceived stress, suggesting that midwives should attempt to improve the general health of women to reduce stress and its consequences during pregnancy by teaching patients appropriate coping styles. Further studies on the effect of coping style interventions on stress are warranted.

  20. Detection of Parent-of-Origin Effects Using General Pedigree Data

    PubMed Central

    Zhou, Ji-Yuan; Ding, Jie; Fung, Wing K.; Lin, Shili

    2010-01-01

    Genomic imprinting is an important epigenetic factor in complex traits study, which has generally been examined by testing for parent-of-origin effects of alleles. For a diallelic marker locus, the parental-asymmetry test (PAT) based on case-parents trios and its extensions to incomplete nuclear families (1-PAT and C-PAT) are simple and powerful for detecting parent-of-origin effects. However, these methods are suitable only for nuclear families and thus are not amenable to general pedigree data. Use of data from extended pedigrees, if available, may lead to more powerful methods than randomly selecting one two-generation nuclear family from each pedigree. In this study, we extend PAT to accommodate general pedigree data by proposing the pedigree PAT (PPAT) statistic, which uses all informative family trios from pedigrees. To fully utilize pedigrees with some missing genotypes, we further develop the Monte Carlo (MC) PPAT (MCPPAT) statistic based on MC sampling and estimation. Extensive simulations were carried out to evaluate the performance of the proposed methods. Under the assumption that the pedigrees and their associated affection patterns are randomly drawn from a population of pedigrees with at least one affected offspring, we demonstrated that MCPPAT is a valid test for parent-of-origin effects in the presence of association. Further, MCPPAT is much more powerful compared to PAT for trios or even PPAT for all informative family trios from the same pedigrees if there is missing data. Application of the proposed methods to a rheumatoid arthritis dataset further demonstrates the advantage of MCPPAT. PMID:19676055

  1. Large deviation approach to the generalized random energy model

    NASA Astrophysics Data System (ADS)

    Dorlas, T. C.; Dukes, W. M. B.

    2002-05-01

    The generalized random energy model is a generalization of the random energy model introduced by Derrida to mimic the ultrametric structure of the Parisi solution of the Sherrington-Kirkpatrick model of a spin glass. It was solved exactly in two special cases by Derrida and Gardner. A complete solution for the thermodynamics in the general case was given by Capocaccia et al. Here we use large deviation theory to analyse the model in a very straightforward way. We also show that the variational expression for the free energy can be evaluated easily using the Cauchy-Schwarz inequality.

  2. Preferential selection based on degree difference in the spatial prisoner's dilemma games

    NASA Astrophysics Data System (ADS)

    Huang, Changwei; Dai, Qionglin; Cheng, Hongyan; Li, Haihong

    2017-10-01

    Strategy evolution in spatial evolutionary games is generally implemented through imitation processes between individuals. In most previous studies, it is assumed that individuals pick up one of their neighbors randomly to learn from. However, by considering the heterogeneity of individuals' influence in the real society, preferential selection is more realistic. Here, we introduce a preferential selection mechanism based on degree difference into spatial prisoner's dilemma games on Erdös-Rényi networks and Barabási-Albert scale-free networks and investigate the effects of the preferential selection on cooperation. The results show that, when the individuals prefer to choose the neighbors who have small degree difference with themselves to imitate, cooperation is hurt by the preferential selection. In contrast, when the individuals prefer to choose those large degree difference neighbors to learn from, there exists optimal preference strength resulting in the maximal cooperation level no matter what the network structure is. In addition, we investigate the robustness of the results against variations of the noise, the average degree and the size of network in the model, and find that the qualitative features of the results are unchanged.

  3. Adaptive consensus of scale-free multi-agent system by randomly selecting links

    NASA Astrophysics Data System (ADS)

    Mou, Jinping; Ge, Huafeng

    2016-06-01

    This paper investigates an adaptive consensus problem for distributed scale-free multi-agent systems (SFMASs) by randomly selecting links, where the degree of each node follows a power-law distribution. The randomly selecting links are based on the assumption that every agent decides to select links among its neighbours according to the received data with a certain probability. Accordingly, a novel consensus protocol with the range of the received data is developed, and each node updates its state according to the protocol. By the iterative method and Cauchy inequality, the theoretical analysis shows that all errors among agents converge to zero, and in the meanwhile, several criteria of consensus are obtained. One numerical example shows the reliability of the proposed methods.

  4. Unbiased split variable selection for random survival forests using maximally selected rank statistics.

    PubMed

    Wright, Marvin N; Dankowski, Theresa; Ziegler, Andreas

    2017-04-15

    The most popular approach for analyzing survival data is the Cox regression model. The Cox model may, however, be misspecified, and its proportionality assumption may not always be fulfilled. An alternative approach for survival prediction is random forests for survival outcomes. The standard split criterion for random survival forests is the log-rank test statistic, which favors splitting variables with many possible split points. Conditional inference forests avoid this split variable selection bias. However, linear rank statistics are utilized by default in conditional inference forests to select the optimal splitting variable, which cannot detect non-linear effects in the independent variables. An alternative is to use maximally selected rank statistics for the split point selection. As in conditional inference forests, splitting variables are compared on the p-value scale. However, instead of the conditional Monte-Carlo approach used in conditional inference forests, p-value approximations are employed. We describe several p-value approximations and the implementation of the proposed random forest approach. A simulation study demonstrates that unbiased split variable selection is possible. However, there is a trade-off between unbiased split variable selection and runtime. In benchmark studies of prediction performance on simulated and real datasets, the new method performs better than random survival forests if informative dichotomous variables are combined with uninformative variables with more categories and better than conditional inference forests if non-linear covariate effects are included. In a runtime comparison, the method proves to be computationally faster than both alternatives, if a simple p-value approximation is used. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Moving a randomized clinical trial into an observational cohort.

    PubMed

    Goodman, Phyllis J; Hartline, Jo Ann; Tangen, Catherine M; Crowley, John J; Minasian, Lori M; Klein, Eric A; Cook, Elise D; Darke, Amy K; Arnold, Kathryn B; Anderson, Karen; Yee, Monica; Meyskens, Frank L; Baker, Laurence H

    2013-02-01

    The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double-blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute (NCI) and conducted by the Southwest Oncology Group (SWOG). A total of 35,533 men were assigned randomly to one of the four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, and placebo + placebo). The independent Data and Safety Monitoring Committee (DSMC) recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort. A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-Up (CFU) study. The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada, and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants. At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of 31 December 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site institutional review boards (IRBs). However, from this cohort, we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher grade cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved. The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository, and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas. Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up.

  6. Moving a Randomized Clinical Trial into an Observational Cohort

    PubMed Central

    Goodman, Phyllis J.; Hartline, Jo Ann; Tangen, Catherine M.; Crowley, John J.; Minasian, Lori M.; Klein, Eric A.; Cook, Elise D.; Darke, Amy K.; Arnold, Kathryn B.; Anderson, Karen; Yee, Monica; Meyskens, Frank L.; Baker, Laurence H.

    2013-01-01

    Background The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double blind, placebo-controlled prostate cancer prevention study funded by the National Cancer Institute and conducted by SWOG (Southwest Oncology Group). A total of 35,533 men were assigned randomly to one of four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, placebo + placebo. The independent Data and Safety Monitoring Committee recommended the discontinuation of study supplements because of the lack of efficacy for risk reduction and because futility analyses demonstrated no possibility of benefit of the supplements to the anticipated degree (25% reduction in prostate cancer incidence) with additional follow-up. Study leadership agreed that the randomized trial should be terminated but believed that the cohort should be maintained and followed as the additional follow-up would contribute important information to the understanding of the biologic consequences of the intervention. Since the participants no longer needed to be seen in person to assess acute toxicities or to be given study supplements, it was determined that the most efficient and cost-effective way to follow them was via a central coordinated effort. Purpose A number of changes were necessary at the local Study Sites and SELECT Statistical Center to transition to following participants via a Central Coordinating Center. We describe the transition process from a randomized clinical trial to the observational Centralized Follow-up (CFU) study. Methods The process of transitioning SELECT, implemented at more than 400 Study Sites across the United States, Canada and Puerto Rico, entailed many critical decisions and actions including updates to online documents such as the SELECT Workbench and Study Manual, a protocol amendment, reorganization of the Statistical Center, creation of a Transition Committee, development of materials for SELECT Study Sites, development of procedures to close Study Sites, and revision of data collection procedures and the process by which to contact participants. Results At the time of the publication of the primary SELECT results in December 2008, there were 32,569 men alive and currently active in the trial. As of December 31, 2011, 17,761 participants had been registered to the CFU study. This number is less than had been anticipated due to unforeseen difficulties with local Study Site IRBs. However, from this cohort we estimate that an additional 580 prostate cancer cases and 215 Gleason 7 or higher cancers will be identified. Over 109,000 individual items have been mailed to participants. Active SELECT ancillary studies have continued. The substantial SELECT biorepository is available to researchers; requests to use the specimens are reviewed for feasibility and scientific merit. As of April 2012, 12 proposals had been approved. Limitations The accrual goal of the follow-up study was not met, limiting our power to address the study objectives satisfactorily. The CFU study is also dependent on a number of factors including continued funding, continued interest of investigators in the biorepository and the continued contribution of the participants. Our experience may be less pertinent to investigators who wish to follow participants in a treatment trial or participants in prevention trials in other medical areas. Conclusions Extended follow-up of participants in prevention research is important to study the long-term effects of the interventions, such as those used in SELECT. The approach taken by SELECT investigators was to continue to follow participants centrally via an annual questionnaire and with a web-based option. The participants enrolled in the CFU study represent a large, well-characterized, generally healthy cohort. The CFU has enabled us to collect additional prostate and other cancer endpoints and longer follow-up on the almost 18,000 participants enrolled. The utility of the extensive biorepository that was developed during the course of the SELECT is enhanced by longer follow-up. PMID:23064404

  7. A generalized model via random walks for information filtering

    NASA Astrophysics Data System (ADS)

    Ren, Zhuo-Ming; Kong, Yixiu; Shang, Ming-Sheng; Zhang, Yi-Cheng

    2016-08-01

    There could exist a simple general mechanism lurking beneath collaborative filtering and interdisciplinary physics approaches which have been successfully applied to online E-commerce platforms. Motivated by this idea, we propose a generalized model employing the dynamics of the random walk in the bipartite networks. Taking into account the degree information, the proposed generalized model could deduce the collaborative filtering, interdisciplinary physics approaches and even the enormous expansion of them. Furthermore, we analyze the generalized model with single and hybrid of degree information on the process of random walk in bipartite networks, and propose a possible strategy by using the hybrid degree information for different popular objects to toward promising precision of the recommendation.

  8. Encouraging the installation of rollover protective structures in New York State: the design of a social marketing intervention.

    PubMed

    Sorensen, Julie A; May, John; Ostby-Malling, Ronne; Lehmen, Tom; Strand, John; Stenlund, Hans; Weinehall, Lars; Einehall, Lars W; Emmelin, Maria

    2008-11-01

    Increasing the percentage of rollover protective structure (ROPS) equipped tractors has been the focus of many agricultural safety campaigns. Traditionally efforts have attempted to persuade farmers through education or community awareness interventions. These efforts have lead to marginal change. In response, a social marketing approach was tested as a means for increasing interest in ROPS retrofitting in New York. An initial phone survey was conducted with a random sample of New York farmers to identify a potential target population. Following target selection, in-depth interviews were conducted to isolate barriers and motivators to retrofitting. This information was used to develop message prototypes which were tested in small focus group discussions. Selected and revised messages, as well as various other incentives developed in response to feedback from interviews, were then tested in a prospective, quasi-randomized controlled trial. Small crop and livestock farms were selected as the intervention target since they represent 86% of New York farms with none or only one ROPS protected tractor. Barriers to retrofitting which were identified in interviews were: 1) constant exposures normalize risk, 2) risk is modeled by significant others and 3) safety in general and retrofitting in particular requires too much time and money. The piloting of ROPS incentives led to a marked increase in ROPS sales in New York. Social Marketing provides a promising framework for the design of agricultural injury prevention programs. The potential implications for other health initiatives seeking to promote behaviour change are also discussed.

  9. Development of Peritoneal Tumor-Targeting Vector by In Vivo Screening with a Random Peptide-Displaying Adenovirus Library

    PubMed Central

    Yoshida, Kimiko; Goto, Naoko; Ohnami, Shumpei; Aoki, Kazunori

    2012-01-01

    The targeting of gene transfer at the cell-entry level is one of the most attractive challenges in vector development. However, attempts to redirect adenovirus vectors to alternative receptors by engineering the capsid-coding region have shown limited success, because the proper targeting ligands on the cells of interest are generally unknown. To overcome this limitation, we have constructed a random peptide library displayed on the adenoviral fiber knob, and have successfully selected targeted vectors by screening the library on cancer cell lines in vitro. The infection of targeted vectors was considered to be mediated by specific receptors on target cells. However, the expression levels and kinds of cell surface receptors may be substantially different between in vitro culture and in vivo tumor tissue. Here, we screened the peptide display-adenovirus library in the peritoneal dissemination model of AsPC-1 pancreatic cancer cells. The vector displaying a selected peptide (PFWSGAV) showed higher infectivity in the AsPC-1 peritoneal tumors but not in organs and other peritoneal tumors as compared with a non-targeted vector. Furthermore, the infectivity of the PFWSGAV-displaying vector for AsPC-1 peritoneal tumors was significantly higher than that of a vector displaying a peptide selected by in vitro screening, indicating the usefulness of in vivo screening in exploring the targeting vectors. This vector-screening system can facilitate the development of targeted adenovirus vectors for a variety of applications in medicine. PMID:23029088

  10. Sex differences in fluctuating asymmetry of body traits in chewing lice Docophorulus coarctatus (Phthiraptera: Ischnocera).

    PubMed

    Tryjanowski, Piotr; Adamski, Zbigniew

    2007-10-01

    Fluctuating asymmetry (FA) that reflects randomly directed deviations from bilateral symmetry has been shown to increase in organisms exposed to environmental and/or genetic stress. We studied fluctuating asymmetry in head and prothorax of chewing lice Docophorulus coarctatus, a parasite of the great grey shrike Lanius excubitor, to investigate associations between parasite body size and fluctuating asymmetry. Samples of ten individual lice (five females, five males) were randomly collected for measurements from 32 shrikes. Relative FA (scaled to trait size) was estimated for head and prothorax. Sex and trait differences in FA were very distinct (all differences significant at P<0.001). However, relative FA of head was not a predictor to relative FA of prothorax in either sex. Moreover, relative FA measurements of females and males from the same host were not significantly correlated, contrary to expectation if hosts imposed similar selection pressures on parasites of the two sexes. Relative FA of a trait was negatively related to its size, except for the relationship between relative FA of prothorax and prothorax in females. Differences in FA between traits may be explained by time when host condition affects louse developmental biology, with the head developing in a very short time during larval and nymph stages. The sex difference in asymmetry was probably related to different selection pressures by hosts on the sexes of the parasite, with females generally being under more intense selection.

  11. Estimating the efficacy of Alcoholics Anonymous without self-selection bias: An instrumental variables re-analysis of randomized clinical trials

    PubMed Central

    Humphreys, Keith; Blodgett, Janet C.; Wagner, Todd H.

    2014-01-01

    Background Observational studies of Alcoholics Anonymous’ (AA) effectiveness are vulnerable to self-selection bias because individuals choose whether or not to attend AA. The present study therefore employed an innovative statistical technique to derive a selection bias-free estimate of AA’s impact. Methods Six datasets from 5 National Institutes of Health-funded randomized trials (one with two independent parallel arms) of AA facilitation interventions were analyzed using instrumental variables models. Alcohol dependent individuals in one of the datasets (n = 774) were analyzed separately from the rest of sample (n = 1582 individuals pooled from 5 datasets) because of heterogeneity in sample parameters. Randomization itself was used as the instrumental variable. Results Randomization was a good instrument in both samples, effectively predicting increased AA attendance that could not be attributed to self-selection. In five of the six data sets, which were pooled for analysis, increased AA attendance that was attributable to randomization (i.e., free of self-selection bias) was effective at increasing days of abstinence at 3-month (B = .38, p = .001) and 15-month (B = 0.42, p = .04) follow-up. However, in the remaining dataset, in which pre-existing AA attendance was much higher, further increases in AA involvement caused by the randomly assigned facilitation intervention did not affect drinking outcome. Conclusions For most individuals seeking help for alcohol problems, increasing AA attendance leads to short and long term decreases in alcohol consumption that cannot be attributed to self-selection. However, for populations with high pre-existing AA involvement, further increases in AA attendance may have little impact. PMID:25421504

  12. Estimating the efficacy of Alcoholics Anonymous without self-selection bias: an instrumental variables re-analysis of randomized clinical trials.

    PubMed

    Humphreys, Keith; Blodgett, Janet C; Wagner, Todd H

    2014-11-01

    Observational studies of Alcoholics Anonymous' (AA) effectiveness are vulnerable to self-selection bias because individuals choose whether or not to attend AA. The present study, therefore, employed an innovative statistical technique to derive a selection bias-free estimate of AA's impact. Six data sets from 5 National Institutes of Health-funded randomized trials (1 with 2 independent parallel arms) of AA facilitation interventions were analyzed using instrumental variables models. Alcohol-dependent individuals in one of the data sets (n = 774) were analyzed separately from the rest of sample (n = 1,582 individuals pooled from 5 data sets) because of heterogeneity in sample parameters. Randomization itself was used as the instrumental variable. Randomization was a good instrument in both samples, effectively predicting increased AA attendance that could not be attributed to self-selection. In 5 of the 6 data sets, which were pooled for analysis, increased AA attendance that was attributable to randomization (i.e., free of self-selection bias) was effective at increasing days of abstinence at 3-month (B = 0.38, p = 0.001) and 15-month (B = 0.42, p = 0.04) follow-up. However, in the remaining data set, in which preexisting AA attendance was much higher, further increases in AA involvement caused by the randomly assigned facilitation intervention did not affect drinking outcome. For most individuals seeking help for alcohol problems, increasing AA attendance leads to short- and long-term decreases in alcohol consumption that cannot be attributed to self-selection. However, for populations with high preexisting AA involvement, further increases in AA attendance may have little impact. Copyright © 2014 by the Research Society on Alcoholism.

  13. Evidence Synthesis in Harm Assessment of Medicines Using the Example of Rosiglitazone and Myocardial Infarction.

    PubMed

    Rietbergen, Charlotte; Stefansdottir, Gudrun; Leufkens, Hubert G; Knol, Mirjam J; De Bruin, Marie L; Klugkist, Irene

    2017-01-01

    The current system of harm assessment of medicines has been criticized for relying on intuitive expert judgment. There is a call for more quantitative approaches and transparency in decision-making. Illustrated with the case of cardiovascular safety concerns for rosiglitazone, we aimed to explore a structured procedure for the collection, quality assessment, and statistical modeling of safety data from observational and randomized studies. We distinguished five stages in the synthesis process. In Stage I, the general research question, population and outcome, and general inclusion and exclusion criteria are defined and a systematic search is performed. Stage II focusses on the identification of sub-questions examined in the included studies and the classification of the studies into the different categories of sub-questions. In Stage III, the quality of the identified studies is assessed. Coding and data extraction are performed in Stage IV. Finally, meta-analyses on the study results per sub-question are performed in Stage V. A Pubmed search identified 30 randomized and 14 observational studies meeting our search criteria. From these studies, we identified 4 higher level sub-questions and 4 lower level sub-questions. We were able to categorize 29 individual treatment comparisons into one or more of the sub-question categories, and selected study duration as an important covariate. We extracted covariate, outcome, and sample size information at the treatment arm level of the studies. We extracted absolute numbers of myocardial infarctions from the randomized study, and adjusted risk estimates with 95% confidence intervals from the observational studies. Overall, few events were observed in the randomized studies that were frequently of relatively short duration. The large observational studies provided more information since these were often of longer duration. A Bayesian random effects meta-analysis on these data showed no significant increase in risk of rosiglitazone for any of the sub-questions. The proposed procedure can be of additional value for drug safety assessment because it provides a stepwise approach that guides the decision-making in increasing process transparency. The procedure allows for the inclusion of results from both randomized an observational studies, which is especially relevant for this type of research.

  14. Extensively Parameterized Mutation-Selection Models Reliably Capture Site-Specific Selective Constraint.

    PubMed

    Spielman, Stephanie J; Wilke, Claus O

    2016-11-01

    The mutation-selection model of coding sequence evolution has received renewed attention for its use in estimating site-specific amino acid propensities and selection coefficient distributions. Two computationally tractable mutation-selection inference frameworks have been introduced: One framework employs a fixed-effects, highly parameterized maximum likelihood approach, whereas the other employs a random-effects Bayesian Dirichlet Process approach. While both implementations follow the same model, they appear to make distinct predictions about the distribution of selection coefficients. The fixed-effects framework estimates a large proportion of highly deleterious substitutions, whereas the random-effects framework estimates that all substitutions are either nearly neutral or weakly deleterious. It remains unknown, however, how accurately each method infers evolutionary constraints at individual sites. Indeed, selection coefficient distributions pool all site-specific inferences, thereby obscuring a precise assessment of site-specific estimates. Therefore, in this study, we use a simulation-based strategy to determine how accurately each approach recapitulates the selective constraint at individual sites. We find that the fixed-effects approach, despite its extensive parameterization, consistently and accurately estimates site-specific evolutionary constraint. By contrast, the random-effects Bayesian approach systematically underestimates the strength of natural selection, particularly for slowly evolving sites. We also find that, despite the strong differences between their inferred selection coefficient distributions, the fixed- and random-effects approaches yield surprisingly similar inferences of site-specific selective constraint. We conclude that the fixed-effects mutation-selection framework provides the more reliable software platform for model application and future development. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. The reduction of occupational stress among elderly lawyers: the creation of a functional niche.

    PubMed

    Meltzer, M W

    1981-01-01

    The question of how older lawyers function in the context of what is generally a high stress occupation is examined from data drawn from a random stratified sample of 130 members of the legal profession. It is shown that elderly lawyers are able to reduce work stress (largely deriving from volume, responsibility, clients, and trials) by control over the quantity and focus of their work, as well as through client selection. Elderly lawyers are able to create a relatively stress free work role, which is in fact a functional niche for them within the profession. The result is high job satisfaction and low rates of retirement among elderly practitioners. Two factors: work role compensation and work role autonomy, are isolated from the legal data and proposed as important variables in a general theory of retirement behavior.

  16. Collaboration between general practitioners and occupational physicians: a comparison of the results of two national surveys in France.

    PubMed

    Verger, Pierre; Ménard, Colette; Richard, Jean-Baptiste; Demortière, Gérard; Beck, François

    2014-02-01

    To study the perceptions that general practitioners (GPs) and occupational physicians (OPs) have of GPs' role in occupational health and their willingness to work together to prevent the exclusion of patients with disabilities from the workplace. Cross-sectional telephone survey of two randomly selected national samples of GPs and OPs was conducted. The majority of GPs and OPs are in favor of cooperation, especially to prevent exclusion from the workplace. However, some GPs lack trust in OPs' independence, an attitude associated negatively with the practice of GP referral to OPs to anticipate disability-related problems likely to occur when returning to work after a prolonged sick leave. There are some barriers to cooperation, on the part of both OPs and GPs. Initiatives are needed to encourage cooperation between these two types of physicians.

  17. Evaluation of generalized degrees of freedom for sparse estimation by replica method

    NASA Astrophysics Data System (ADS)

    Sakata, A.

    2016-12-01

    We develop a method to evaluate the generalized degrees of freedom (GDF) for linear regression with sparse regularization. The GDF is a key factor in model selection, and thus its evaluation is useful in many modelling applications. An analytical expression for the GDF is derived using the replica method in the large-system-size limit with random Gaussian predictors. The resulting formula has a universal form that is independent of the type of regularization, providing us with a simple interpretation. Within the framework of replica symmetric (RS) analysis, GDF has a physical meaning as the effective fraction of non-zero components. The validity of our method in the RS phase is supported by the consistency of our results with previous mathematical results. The analytical results in the RS phase are calculated numerically using the belief propagation algorithm.

  18. Random walk in generalized quantum theory

    NASA Astrophysics Data System (ADS)

    Martin, Xavier; O'Connor, Denjoe; Sorkin, Rafael D.

    2005-01-01

    One can view quantum mechanics as a generalization of classical probability theory that provides for pairwise interference among alternatives. Adopting this perspective, we “quantize” the classical random walk by finding, subject to a certain condition of “strong positivity”, the most general Markovian, translationally invariant “decoherence functional” with nearest neighbor transitions.

  19. Evolving artificial metalloenzymes via random mutagenesis

    NASA Astrophysics Data System (ADS)

    Yang, Hao; Swartz, Alan M.; Park, Hyun June; Srivastava, Poonam; Ellis-Guardiola, Ken; Upp, David M.; Lee, Gihoon; Belsare, Ketaki; Gu, Yifan; Zhang, Chen; Moellering, Raymond E.; Lewis, Jared C.

    2018-03-01

    Random mutagenesis has the potential to optimize the efficiency and selectivity of protein catalysts without requiring detailed knowledge of protein structure; however, introducing synthetic metal cofactors complicates the expression and screening of enzyme libraries, and activity arising from free cofactor must be eliminated. Here we report an efficient platform to create and screen libraries of artificial metalloenzymes (ArMs) via random mutagenesis, which we use to evolve highly selective dirhodium cyclopropanases. Error-prone PCR and combinatorial codon mutagenesis enabled multiplexed analysis of random mutations, including at sites distal to the putative ArM active site that are difficult to identify using targeted mutagenesis approaches. Variants that exhibited significantly improved selectivity for each of the cyclopropane product enantiomers were identified, and higher activity than previously reported ArM cyclopropanases obtained via targeted mutagenesis was also observed. This improved selectivity carried over to other dirhodium-catalysed transformations, including N-H, S-H and Si-H insertion, demonstrating that ArMs evolved for one reaction can serve as starting points to evolve catalysts for others.

  20. Effect of systematic review of medication by general practitioner on drug consumption among nursing-home residents.

    PubMed

    Khunti, K; Kinsella, B

    2000-09-01

    nursing-home patients usually have many medical problems and often take many drugs. They are therefore at risk from drug side effects and interactions. to evaluate the impact of a visit by a general practitioner and a comprehensive repeat prescribing review on the consumption of inappropriate drugs in nursing homes. two general practitioners made one comprehensive visit to four randomly selected nursing homes. In each home we discussed all patients in detail with a senior member of staff. We reviewed the prescribing record of each patient and stopped items if we considered them inappropriately prescribed or unnecessary. repeat prescriptions were altered in 65% of patients: 51% had an item stopped and 26% had an item changed to a cheaper alternative or the dose reduced. There was a reduction in the mean number of repeat prescriptions prescribed. a single visit by a general practitioner to a nursing home and a comprehensive repeat prescribing review can lead to a reduction in the number of items prescribed and to substantial savings for the health service. Further rigorous, cost-effectiveness studies are needed.

  1. The influence of an academic representative on prescribing by general practitioners.

    PubMed Central

    Newton-Syms, F A; Dawson, P H; Cooke, J; Feely, M; Booth, T G; Jerwood, D; Calvert, R T

    1992-01-01

    1. The effect of providing information about medicines by a short 'sales' interview between individual general practitioners and an 'academic representative' on prescribing was investigated. 2. The promotional campaign was designed to encourage a rational approach to prescribing of non-steroidal anti-inflammatory agents in an intervention group of 101 general practitioners selected at random from the Leeds Family Practitioner Committee (FPC). The remaining general practitioners in the Leeds FPC acted as a reference group. 3. The prescribing data for each group for 5 months immediately prior to and 5 months following intervention were compared. 4. Intervention produced a significant increase (P less than 0.005) in the prescribing cost of ibuprofen, the non-steroidal promoted as first choice agent, which was sustained for at least 5 months. 5. Prescribing of the second choice agent, piroxicam, decreased in the reference group but not in the intervention group. 6. There was a decrease in the average prescribing cost of pounds 6.60 per doctor per month in the intervention group compared with the reference group. PMID:1540493

  2. Fast Principal-Component Analysis Reveals Convergent Evolution of ADH1B in Europe and East Asia

    PubMed Central

    Galinsky, Kevin J.; Bhatia, Gaurav; Loh, Po-Ru; Georgiev, Stoyan; Mukherjee, Sayan; Patterson, Nick J.; Price, Alkes L.

    2016-01-01

    Searching for genetic variants with unusual differentiation between subpopulations is an established approach for identifying signals of natural selection. However, existing methods generally require discrete subpopulations. We introduce a method that infers selection using principal components (PCs) by identifying variants whose differentiation along top PCs is significantly greater than the null distribution of genetic drift. To enable the application of this method to large datasets, we developed the FastPCA software, which employs recent advances in random matrix theory to accurately approximate top PCs while reducing time and memory cost from quadratic to linear in the number of individuals, a computational improvement of many orders of magnitude. We apply FastPCA to a cohort of 54,734 European Americans, identifying 5 distinct subpopulations spanning the top 4 PCs. Using the PC-based test for natural selection, we replicate previously known selected loci and identify three new genome-wide significant signals of selection, including selection in Europeans at ADH1B. The coding variant rs1229984∗T has previously been associated to a decreased risk of alcoholism and shown to be under selection in East Asians; we show that it is a rare example of independent evolution on two continents. We also detect selection signals at IGFBP3 and IGH, which have also previously been associated to human disease. PMID:26924531

  3. What keeps Melbourne GPs satisfied in their jobs?

    PubMed

    Walker, Kate Anne; Pirotta, Marie

    2007-10-01

    Workforce shortages make it important to promote job satisfaction and career longevity in general practitioners. We aimed to investigate strategies that maintain and improve Melbourne (Victoria) GP job satisfaction. A postal survey of a random selection of The Royal Australian College of General Practitioners vocationally recognised GPs (N=860). Open ended answers were coded according to themes and compared between genders. Thirty-eight percent of surveyed GPs responded. The mean satisfaction score was 50 out of 70 (SD 9). Women GPs were more satisfied than men with life-work balance (p<0.01). Most frequently nominated themes for satisfaction were job variety, longitudinal patient relationships, belief in the value of the work and intellectual stimulation. Strategies to improve GP satisfaction were increased pay, reduced paperwork, and improved administrative systems. General practitioners were satisfied with their jobs due to the intrinsic qualities of their work and workplace. Decreasing the administrative burden, increasing remuneration and improving practice supports may improve metropolitan GP job satisfaction.

  4. Investigating tiredness in Australian general practice. Do pathology tests help in diagnosis?

    PubMed

    Gialamas, Angela; Beilby, Justin J; Pratt, Nicole L; Henning, Rhys; Marley, John E; Roddick, John F

    2003-08-01

    Tiredness is a common presentation in general practice for which pathology tests are commonly ordered. Our aim was to study their utilisation for tiredness. We examined an integrated database which contains the medical records for 58,139 patients and their 696,518 associated general practitioner encounters. Three hundred and forty-two patients and their 1652 associated encounters were randomly selected out of 12,291 patients and their 26,748 associated encounters that had mentioned tiredness (or a synonym). One hundred and eighty-one patients (53%) had at least one pathology test ordered at any time in their episode of care. Patients over 60 years of age, patients who consulted their GP more than once and patients without comorbidity were more likely to have a pathology test ordered. Only 12 patients (3%) had a significant clinical diagnosis based on an abnormal pathology test. Pathology testing for patients presenting with tiredness is high. Most tests do not yield a significant clinical diagnosis.

  5. Musculoskeletal symptoms as related to ergonomic factors in Iranian hand-woven carpet industry and general guidelines for workstation design.

    PubMed

    Choobineh, Alireza; Lahmi, Mohammadali; Shahnavaz, Houshang; Jazani, Reza Khani; Hosseini, Mostafa

    2004-01-01

    Carpet weaving is a high risk occupation for developing musculoskeletal disorders (MSDs). The objectives of the present study, which was carried out in the Iranian hand-woven carpet industry, were determination of the prevalence of MSD symptoms, identification of major factors associated with MSD symptoms and development of guidelines for workstation design. 1,439 randomly selected weavers participated in this study. A questionnaire was used to collect data on MSD symptoms. The results revealed that the prevalence rates for symptoms in different body regions were high as compared to the general Iranian population (for neck, back and large joints, p <.0001). The results of multivariate analyses showed that major ergonomic factors associated with musculoskeletal symptoms were loom type, working posture, daily working time and seat type. Based on the results, some general guidelines for designing weaving workstations were developed. A prototype test showed that the new workstation was acceptable for subject tests and that it improved working posture.

  6. Refernce Conditions for Streams in the Grand Prairie Natural Division of Illinois

    NASA Astrophysics Data System (ADS)

    Sangunett, B.; Dewalt, R.

    2005-05-01

    As part of the Critical Trends Assessment Program (CTAP) of the Illinois Department of Natural Resources (IDNR), 12 potential reference quality stream sites in the Grand Prairie Natural Division were evaluated in May 2004. This agriculturally dominated region, located in east central Illinois, is the most highly modified in the state. The quality of these sites was assessed using a modified Hilsenhoff Biotic Index and species richness of Ephemeroptera, Plecoptera, and Trichoptera (EPT) insect orders and a 12 parameter Habitat Quality Index (HQI). Illinois EPA high quality fish stations, Illinois Natural History Survey insect collection data, and best professional knowledge were used to choose which streams to evaluate. For analysis, reference quality streams were compared to 37 randomly selected meandering streams and 26 randomly selected channelized streams which were assessed by CTAP between 1997 and 2001. The results showed that the reference streams exceeded both taxa richness and habitat quality of randomly selected streams in the region. Both random meandering sites and reference quality sites increased in taxa richness and HQI as stream width increased. Randomly selected channelized streams had about the same taxa richness and HQI regardless of width.

  7. Methods and analysis of realizing randomized grouping.

    PubMed

    Hu, Liang-Ping; Bao, Xiao-Lei; Wang, Qi

    2011-07-01

    Randomization is one of the four basic principles of research design. The meaning of randomization includes two aspects: one is to randomly select samples from the population, which is known as random sampling; the other is to randomly group all the samples, which is called randomized grouping. Randomized grouping can be subdivided into three categories: completely, stratified and dynamically randomized grouping. This article mainly introduces the steps of complete randomization, the definition of dynamic randomization and the realization of random sampling and grouping by SAS software.

  8. An active learning representative subset selection method using net analyte signal.

    PubMed

    He, Zhonghai; Ma, Zhenhe; Luan, Jingmin; Cai, Xi

    2018-05-05

    To guarantee accurate predictions, representative samples are needed when building a calibration model for spectroscopic measurements. However, in general, it is not known whether a sample is representative prior to measuring its concentration, which is both time-consuming and expensive. In this paper, a method to determine whether a sample should be selected into a calibration set is presented. The selection is based on the difference of Euclidean norm of net analyte signal (NAS) vector between the candidate and existing samples. First, the concentrations and spectra of a group of samples are used to compute the projection matrix, NAS vector, and scalar values. Next, the NAS vectors of candidate samples are computed by multiplying projection matrix with spectra of samples. Scalar value of NAS is obtained by norm computation. The distance between the candidate set and the selected set is computed, and samples with the largest distance are added to selected set sequentially. Last, the concentration of the analyte is measured such that the sample can be used as a calibration sample. Using a validation test, it is shown that the presented method is more efficient than random selection. As a result, the amount of time and money spent on reference measurements is greatly reduced. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Differential evolution enhanced with multiobjective sorting-based mutation operators.

    PubMed

    Wang, Jiahai; Liao, Jianjun; Zhou, Ying; Cai, Yiqiao

    2014-12-01

    Differential evolution (DE) is a simple and powerful population-based evolutionary algorithm. The salient feature of DE lies in its mutation mechanism. Generally, the parents in the mutation operator of DE are randomly selected from the population. Hence, all vectors are equally likely to be selected as parents without selective pressure at all. Additionally, the diversity information is always ignored. In order to fully exploit the fitness and diversity information of the population, this paper presents a DE framework with multiobjective sorting-based mutation operator. In the proposed mutation operator, individuals in the current population are firstly sorted according to their fitness and diversity contribution by nondominated sorting. Then parents in the mutation operators are proportionally selected according to their rankings based on fitness and diversity, thus, the promising individuals with better fitness and diversity have more opportunity to be selected as parents. Since fitness and diversity information is simultaneously considered for parent selection, a good balance between exploration and exploitation can be achieved. The proposed operator is applied to original DE algorithms, as well as several advanced DE variants. Experimental results on 48 benchmark functions and 12 real-world application problems show that the proposed operator is an effective approach to enhance the performance of most DE algorithms studied.

  10. An active learning representative subset selection method using net analyte signal

    NASA Astrophysics Data System (ADS)

    He, Zhonghai; Ma, Zhenhe; Luan, Jingmin; Cai, Xi

    2018-05-01

    To guarantee accurate predictions, representative samples are needed when building a calibration model for spectroscopic measurements. However, in general, it is not known whether a sample is representative prior to measuring its concentration, which is both time-consuming and expensive. In this paper, a method to determine whether a sample should be selected into a calibration set is presented. The selection is based on the difference of Euclidean norm of net analyte signal (NAS) vector between the candidate and existing samples. First, the concentrations and spectra of a group of samples are used to compute the projection matrix, NAS vector, and scalar values. Next, the NAS vectors of candidate samples are computed by multiplying projection matrix with spectra of samples. Scalar value of NAS is obtained by norm computation. The distance between the candidate set and the selected set is computed, and samples with the largest distance are added to selected set sequentially. Last, the concentration of the analyte is measured such that the sample can be used as a calibration sample. Using a validation test, it is shown that the presented method is more efficient than random selection. As a result, the amount of time and money spent on reference measurements is greatly reduced.

  11. Different views of dentists and general medical practitioners on dental care for patients with diabetes mellitus and coronary heart diseases: results of a questionnaire-based survey in a district of Germany.

    PubMed

    Ziebolz, Dirk; Reiss, Lucie; Schmalz, Gerhard; Krause, Felix; Haak, Rainer; Mausberg, Rainer F

    2018-06-01

    The aim of this questionnaire-based study was to evaluate the views of dentists (Ds) and general medical practitioners (GPs) on different aspects of dental care for patients with diabetes mellitus (DM) or coronary heart disease (CHD). Reliable and comparable questionnaires for Ds and GPs, with 23 questions, were sent to 1,000 randomly selected Ds and 1,000 randomly selected GPs. Questions were asked about patients with DM or CHD regarding their dental care and potentially related issues (e.g. antibiotic prophylaxis). The responses received within 12 weeks were evaluated and statistically analysed using chi-square and Mann-Whitney U tests (P < 0.05). The response rate was 39% (n = 391) for Ds and 18% (n = 181) for GPs. Both groups stated that they used the medical history as well as patient interviews to assess patients. However, only 55% of Ds assumed correct identification of every at-risk patient compared with 100% of GPs (P < 0.01). Furthermore, Ds speculated that they inform their patients more often about their at-risk status than do GPs (P < 0.01). Neither Ds nor GPs appeared to be confident in their knowledge about adequate antibiotic prophylaxis. Interdisciplinary collaboration was considered insufficient, although Ds had a higher rate of regular collaboration (68% for Ds vs. 40% for GPs; P < 0.01). Ds and GPs have differing views on dental care of patients with DM or CHD, and Ds showed more interest in this issue. These results might partially explain the insufficient collaboration between Ds and GPs. © 2017 FDI World Dental Federation.

  12. The Incidence, Nature and Consequences of Adverse Events in Iranian Hospitals.

    PubMed

    Akbari Sari, Ali; Doshmangir, Leila; Torabi, Fereshteh; Rashidian, Arash; Sedaghat, Mojtaba; Ghomi, Robabeh; Prasopa-Plaizier, Nittita

    2015-12-01

    Adverse events are relatively common in healthcare, leading to extensive harm to patients and a significant drain on healthcare resources. Identifying the extent, nature and consequences of adverse events is an important step in preventing adverse events and their consequences which is the subject of this study. This is a retrospective review of medical records randomly selected from patients admitted to 4 general hospitals, staying more than 24 hours and discharged between April and September 2012. We randomly selected 1200 records and completed the record review for 1162 of these records. Standard forms (RF1 and RF2) were used to review medical records in two stages by nurses and medical doctors. Eighty-five (7.3%) of the 1162 records had an adverse event during the admission; and in 43 (3.7%) of the 1162 records, the patient was admitted to the hospital due to an adverse event that occurred before the admission. Therefore, a total of 128 (11.0%) adverse events occurred in 126 (10.9) records as two patients had more than one adverse event. Forty-four (34.3%) of these 128 adverse events were considered preventable. This study confirms that adverse events, particularly adverse drug reactions, post-operative infections, bedsore and hospital acquired infections are common and potentially preventable sources of harm to patients in Iranian hospitals.

  13. Unraveling the non-senescence phenomenon in Hydra.

    PubMed

    Dańko, Maciej J; Kozłowski, Jan; Schaible, Ralf

    2015-10-07

    Unlike other metazoans, Hydra does not experience the distinctive rise in mortality with age known as senescence, which results from an increasing imbalance between cell damage and cell repair. We propose that the Hydra controls damage accumulation mainly through damage-dependent cell selection and cell sloughing. We examine our hypothesis with a model that combines cellular damage with stem cell renewal, differentiation, and elimination. The Hydra individual can be seen as a large single pool of three types of stem cells with some features of differentiated cells. This large stem cell community prevents "cellular damage drift," which is inevitable in complex conglomerate (differentiated) metazoans with numerous and generally isolated pools of stem cells. The process of cellular damage drift is based on changes in the distribution of damage among cells due to random events, and is thus similar to Muller's ratchet in asexual populations. Events in the model that are sources of randomness include budding, cellular death, and cellular damage and repair. Our results suggest that non-senescence is possible only in simple Hydra-like organisms which have a high proportion and number of stem cells, continuous cell divisions, an effective cell selection mechanism, and stem cells with the ability to undertake some roles of differentiated cells. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Replication of High Fetal Alcohol Spectrum Disorders Prevalence Rates, Child Characteristics, and Maternal Risk Factors in a Second Sample of Rural Communities in South Africa.

    PubMed

    May, Philip A; De Vries, Marlene M; Marais, Anna-Susan; Kalberg, Wendy O; Buckley, David; Adnams, Colleen M; Hasken, Julie M; Tabachnick, Barbara; Robinson, Luther K; Manning, Melanie A; Bezuidenhout, Heidre; Adam, Margaret P; Jones, Kenneth L; Seedat, Soraya; Parry, Charles D H; Hoyme, H Eugene

    2017-05-12

    Background : Prevalence and characteristics of fetal alcohol syndrome (FAS) and total fetal alcohol spectrum disorders (FASD) were studied in a second sample of three South African rural communities to assess change. Methods : Active case ascertainment focused on children with height, weight and/or head circumference ≤25th centile and randomly-selected children. Final diagnoses were based on dysmorphology, neurobehavioral scores, and maternal risk interviews. Results : Cardinal facial features, head circumference, and total dysmorphology scores differentiated specific FASD diagnostic categories in a somewhat linear fashion but all FASD traits were significantly worse than those of randomly-selected controls. Neurodevelopmental delays were significantly worse for children with FASD than controls. Binge alcohol use was clearly documented as the proximal maternal risk factor for FASD, and significant distal risk factors were: low body mass, education, and income; high gravidity, parity, and age at birth of the index child. FAS rates continue to extremely high in these communities at 9-129 per 1000 children. Total FASD affect 196-276 per 1000 or 20-28% of the children in these communities. Conclusions : Very high rates of FASD persist in these general populations where regular, heavy drinking, often in a binge fashion, co-occurs with low socioeconomic conditions.

  15. Prevalence of cardiovascular risk factors amongst traders in an urban market in Lagos, Nigeria.

    PubMed

    Odugbemi, T O; Onajole, A T; Osibogun, A O

    2012-03-01

    A descriptive cross-sectional study was carried out to determine the prevalence of cardiovascular risk factors amongst traders in an urban market in Lagos State. Tejuosho market, one of the large popular markets was selected from a list of markets that met the inclusion criteria of being major markets dealing in general goods using a simple random sampling technique by balloting. Four hundred (400) traders were selected using a systematic random sampling. Each trader was interviewed with a well-structured questionnaire and had blood pressure and anthropometric measurements (height, weight and body mass index). Female traders made up (74.3%) 297 of the total population. The mean age was 45.48+11.88 and 42.29+10.96 years for males and females respectively. Majority 239 (59.8%) fell within the age range of 35 - 55 years. The cardiovascular risk factors identified and their prevalence rates were hypertension (34.8%), physical inactivity (92%), previously diagnosed diabetes mellitus (0.8%), risky alcohol consumption (1%), cigarette smoking (0.3%) in females and (17.5%) in males, obesity (12.3%) and overweight (39.9%). The study recommended that any health promoting, preventive or intervention programme for this population would have to be worked into their market activities if it is to make an impact.

  16. An approximate generalized linear model with random effects for informative missing data.

    PubMed

    Follmann, D; Wu, M

    1995-03-01

    This paper develops a class of models to deal with missing data from longitudinal studies. We assume that separate models for the primary response and missingness (e.g., number of missed visits) are linked by a common random parameter. Such models have been developed in the econometrics (Heckman, 1979, Econometrica 47, 153-161) and biostatistics (Wu and Carroll, 1988, Biometrics 44, 175-188) literature for a Gaussian primary response. We allow the primary response, conditional on the random parameter, to follow a generalized linear model and approximate the generalized linear model by conditioning on the data that describes missingness. The resultant approximation is a mixed generalized linear model with possibly heterogeneous random effects. An example is given to illustrate the approximate approach, and simulations are performed to critique the adequacy of the approximation for repeated binary data.

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

    PubMed

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

    2001-01-01

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

  18. Informational masking and musical training

    NASA Astrophysics Data System (ADS)

    Oxenham, Andrew J.; Fligor, Brian J.; Mason, Christine R.; Kidd, Gerald

    2003-09-01

    The relationship between musical training and informational masking was studied for 24 young adult listeners with normal hearing. The listeners were divided into two groups based on musical training. In one group, the listeners had little or no musical training; the other group was comprised of highly trained, currently active musicians. The hypothesis was that musicians may be less susceptible to informational masking, which is thought to reflect central, rather than peripheral, limitations on the processing of sound. Masked thresholds were measured in two conditions, similar to those used by Kidd et al. [J. Acoust. Soc. Am. 95, 3475-3480 (1994)]. In both conditions the signal was comprised of a series of repeated tone bursts at 1 kHz. The masker was comprised of a series of multitone bursts, gated with the signal. In one condition the frequencies of the masker were selected randomly for each burst; in the other condition the masker frequencies were selected randomly for the first burst of each interval and then remained constant throughout the interval. The difference in thresholds between the two conditions was taken as a measure of informational masking. Frequency selectivity, using the notched-noise method, was also estimated in the two groups. The results showed no difference in frequency selectivity between the two groups, but showed a large and significant difference in the amount of informational masking between musically trained and untrained listeners. This informational masking task, which requires no knowledge specific to musical training (such as note or interval names) and is generally not susceptible to systematic short- or medium-term training effects, may provide a basis for further studies of analytic listening abilities in different populations.

  19. Random Survival Forest in practice: a method for modelling complex metabolomics data in time to event analysis.

    PubMed

    Dietrich, Stefan; Floegel, Anna; Troll, Martina; Kühn, Tilman; Rathmann, Wolfgang; Peters, Anette; Sookthai, Disorn; von Bergen, Martin; Kaaks, Rudolf; Adamski, Jerzy; Prehn, Cornelia; Boeing, Heiner; Schulze, Matthias B; Illig, Thomas; Pischon, Tobias; Knüppel, Sven; Wang-Sattler, Rui; Drogan, Dagmar

    2016-10-01

    The application of metabolomics in prospective cohort studies is statistically challenging. Given the importance of appropriate statistical methods for selection of disease-associated metabolites in highly correlated complex data, we combined random survival forest (RSF) with an automated backward elimination procedure that addresses such issues. Our RSF approach was illustrated with data from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study, with concentrations of 127 serum metabolites as exposure variables and time to development of type 2 diabetes mellitus (T2D) as outcome variable. Out of this data set, Cox regression with a stepwise selection method was recently published. Replication of methodical comparison (RSF and Cox regression) was conducted in two independent cohorts. Finally, the R-code for implementing the metabolite selection procedure into the RSF-syntax is provided. The application of the RSF approach in EPIC-Potsdam resulted in the identification of 16 incident T2D-associated metabolites which slightly improved prediction of T2D when used in addition to traditional T2D risk factors and also when used together with classical biomarkers. The identified metabolites partly agreed with previous findings using Cox regression, though RSF selected a higher number of highly correlated metabolites. The RSF method appeared to be a promising approach for identification of disease-associated variables in complex data with time to event as outcome. The demonstrated RSF approach provides comparable findings as the generally used Cox regression, but also addresses the problem of multicollinearity and is suitable for high-dimensional data. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  20. Assessing the accuracy and stability of variable selection methods for random forest modeling in ecology

    EPA Science Inventory

    Random forest (RF) modeling has emerged as an important statistical learning method in ecology due to its exceptional predictive performance. However, for large and complex ecological datasets there is limited guidance on variable selection methods for RF modeling. Typically, e...

  1. Genetic improvement in mastitis resistance: comparison of selection criteria from cross-sectional and random regression sire models for somatic cell score.

    PubMed

    Odegård, J; Klemetsdal, G; Heringstad, B

    2005-04-01

    Several selection criteria for reducing incidence of mastitis were developed from a random regression sire model for test-day somatic cell score (SCS). For comparison, sire transmitting abilities were also predicted based on a cross-sectional model for lactation mean SCS. Only first-crop daughters were used in genetic evaluation of SCS, and the different selection criteria were compared based on their correlation with incidence of clinical mastitis in second-crop daughters (measured as mean daughter deviations). Selection criteria were predicted based on both complete and reduced first-crop daughter groups (261 or 65 daughters per sire, respectively). For complete daughter groups, predicted transmitting abilities at around 30 d in milk showed the best predictive ability for incidence of clinical mastitis, closely followed by average predicted transmitting abilities over the entire lactation. Both of these criteria were derived from the random regression model. These selection criteria improved accuracy of selection by approximately 2% relative to a cross-sectional model. However, for reduced daughter groups, the cross-sectional model yielded increased predictive ability compared with the selection criteria based on the random regression model. This result may be explained by the cross-sectional model being more robust, i.e., less sensitive to precision of (co)variance components estimates and effects of data structure.

  2. Design challenges in transdiagnostic psychotherapy research: Comparing Transdiagnostic Behavior Therapy (TBT) to existing evidence-based psychotherapy in veterans with affective disorders.

    PubMed

    Gros, Daniel F

    2015-07-01

    To address the limitations of disorder-specific approaches, newer transdiagnostic approaches to psychotherapy have been developed to provide a single treatment that is capable of addressing several, related disorders. However, the recruitment of multiple diagnoses presents many challenges to the traditional design of psychotherapy randomized controlled trials (RCTs). The goal of the manuscript is to present the challenges and rationale for designing a RCT for transdiagnostic treatment to inform and aid in the development of future investigations. A recently funded and ongoing RCT for Transdiagnostic Behavior Therapy (TBT) is used as an example to discuss the related design challenges. The TBT study involves the recruitment of 96 veteran participants with any of the following eight principal diagnoses: posttraumatic stress disorder, panic disorder, social anxiety disorder, obsessive compulsive disorder, generalized anxiety disorder, specific phobia, major depressive disorder, or persistent depressive disorder. Within the TBT study, participants will complete a semi-structured diagnostic interview and a series of transdiagnostic self-report measures to determine eligibility and assess baseline symptomatology. Qualifying participants will be randomized to TBT or control psychotherapy. Additional assessments will be completed at post-treatment and 6-month follow-up. Due to the transdiagnostic nature of the sample, adjustments to the recruitment and randomization procedures, selection of measures, selection of control psychotherapy, and analysis plan were required. These adjustments have implications to future trials on transdiagnostic psychotherapy protocols as well as future research in line with the transdiagnostic focus of the National Institute of Mental Health's Research Domain Criteria (RDoC) funding strategy. Published by Elsevier Inc.

  3. An Approach to Addressing Selection Bias in Survival Analysis

    PubMed Central

    Carlin, Caroline S.; Solid, Craig A.

    2014-01-01

    This work proposes a frailty model that accounts for non-random treatment assignment in survival analysis. Using Monte Carlo simulation, we found that estimated treatment parameters from our proposed endogenous selection survival model (esSurv) closely parallel the consistent two-stage residual inclusion (2SRI) results, while offering computational and interpretive advantages. The esSurv method greatly enhances computational speed relative to 2SRI by eliminating the need for bootstrapped standard errors, and generally results in smaller standard errors than those estimated by 2SRI. In addition, esSurv explicitly estimates the correlation of unobservable factors contributing to both treatment assignment and the outcome of interest, providing an interpretive advantage over the residual parameter estimate in the 2SRI method. Comparisons with commonly used propensity score methods and with a model that does not account for non-random treatment assignment show clear bias in these methods that is not mitigated by increased sample size. We illustrate using actual dialysis patient data comparing mortality of patients with mature arteriovenous grafts for venous access to mortality of patients with grafts placed but not yet ready for use at the initiation of dialysis. We find strong evidence of endogeneity (with estimate of correlation in unobserved factors ρ̂ = 0.55), and estimate a mature-graft hazard ratio of 0.197 in our proposed method, with a similar 0.173 hazard ratio using 2SRI. The 0.630 hazard ratio from a frailty model without a correction for the non-random nature of treatment assignment illustrates the importance of accounting for endogeneity. PMID:24845211

  4. Randomized controlled trials of simulation-based interventions in Emergency Medicine: a methodological review.

    PubMed

    Chauvin, Anthony; Truchot, Jennifer; Bafeta, Aida; Pateron, Dominique; Plaisance, Patrick; Yordanov, Youri

    2018-04-01

    The number of trials assessing Simulation-Based Medical Education (SBME) interventions has rapidly expanded. Many studies show that potential flaws in design, conduct and reporting of randomized controlled trials (RCTs) can bias their results. We conducted a methodological review of RCTs assessing a SBME in Emergency Medicine (EM) and examined their methodological characteristics. We searched MEDLINE via PubMed for RCT that assessed a simulation intervention in EM, published in 6 general and internal medicine and in the top 10 EM journals. The Cochrane Collaboration risk of Bias tool was used to assess risk of bias, intervention reporting was evaluated based on the "template for intervention description and replication" checklist, and methodological quality was evaluated by the Medical Education Research Study Quality Instrument. Reports selection and data extraction was done by 2 independents researchers. From 1394 RCTs screened, 68 trials assessed a SBME intervention. They represent one quarter of our sample. Cardiopulmonary resuscitation (CPR) is the most frequent topic (81%). Random sequence generation and allocation concealment were performed correctly in 66 and 49% of trials. Blinding of participants and assessors was performed correctly in 19 and 68%. Risk of attrition bias was low in three-quarters of the studies (n = 51). Risk of selective reporting bias was unclear in nearly all studies. The mean MERQSI score was of 13.4/18.4% of the reports provided a description allowing the intervention replication. Trials assessing simulation represent one quarter of RCTs in EM. Their quality remains unclear, and reproducing the interventions appears challenging due to reporting issues.

  5. The Effects of Total Physical Response by Storytelling and the Traditional Teaching Styles of a Foreign Language in a Selected High School

    ERIC Educational Resources Information Center

    Kariuki, Patrick N. K.; Bush, Elizabeth Danielle

    2008-01-01

    The purpose of this study was to examine the effects of Total Physical Response by Storytelling and the traditional teaching method on a foreign language in a selected high school. The sample consisted of 30 students who were randomly selected and randomly assigned to experimental and control group. The experimental group was taught using Total…

  6. Most Undirected Random Graphs Are Amplifiers of Selection for Birth-Death Dynamics, but Suppressors of Selection for Death-Birth Dynamics.

    PubMed

    Hindersin, Laura; Traulsen, Arne

    2015-11-01

    We analyze evolutionary dynamics on graphs, where the nodes represent individuals of a population. The links of a node describe which other individuals can be displaced by the offspring of the individual on that node. Amplifiers of selection are graphs for which the fixation probability is increased for advantageous mutants and decreased for disadvantageous mutants. A few examples of such amplifiers have been developed, but so far it is unclear how many such structures exist and how to construct them. Here, we show that almost any undirected random graph is an amplifier of selection for Birth-death updating, where an individual is selected to reproduce with probability proportional to its fitness and one of its neighbors is replaced by that offspring at random. If we instead focus on death-Birth updating, in which a random individual is removed and its neighbors compete for the empty spot, then the same ensemble of graphs consists of almost only suppressors of selection for which the fixation probability is decreased for advantageous mutants and increased for disadvantageous mutants. Thus, the impact of population structure on evolutionary dynamics is a subtle issue that will depend on seemingly minor details of the underlying evolutionary process.

  7. Using ArcMap, Google Earth, and Global Positioning Systems to select and locate random households in rural Haiti.

    PubMed

    Wampler, Peter J; Rediske, Richard R; Molla, Azizur R

    2013-01-18

    A remote sensing technique was developed which combines a Geographic Information System (GIS); Google Earth, and Microsoft Excel to identify home locations for a random sample of households in rural Haiti. The method was used to select homes for ethnographic and water quality research in a region of rural Haiti located within 9 km of a local hospital and source of health education in Deschapelles, Haiti. The technique does not require access to governmental records or ground based surveys to collect household location data and can be performed in a rapid, cost-effective manner. The random selection of households and the location of these households during field surveys were accomplished using GIS, Google Earth, Microsoft Excel, and handheld Garmin GPSmap 76CSx GPS units. Homes were identified and mapped in Google Earth, exported to ArcMap 10.0, and a random list of homes was generated using Microsoft Excel which was then loaded onto handheld GPS units for field location. The development and use of a remote sensing method was essential to the selection and location of random households. A total of 537 homes initially were mapped and a randomized subset of 96 was identified as potential survey locations. Over 96% of the homes mapped using Google Earth imagery were correctly identified as occupied dwellings. Only 3.6% of the occupants of mapped homes visited declined to be interviewed. 16.4% of the homes visited were not occupied at the time of the visit due to work away from the home or market days. A total of 55 households were located using this method during the 10 days of fieldwork in May and June of 2012. The method used to generate and field locate random homes for surveys and water sampling was an effective means of selecting random households in a rural environment lacking geolocation infrastructure. The success rate for locating households using a handheld GPS was excellent and only rarely was local knowledge required to identify and locate households. This method provides an important technique that can be applied to other developing countries where a randomized study design is needed but infrastructure is lacking to implement more traditional participant selection methods.

  8. Solving da Vinci stereopsis with depth-edge-selective V2 cells

    PubMed Central

    Assee, Andrew; Qian, Ning

    2007-01-01

    We propose a new model for da Vinci stereopsis based on a coarse-to-fine disparity-energy computation in V1 and disparity-boundary-selective units in V2. Unlike previous work, our model contains only binocular cells, relies on distributed representations of disparity, and has a simple V1-to-V2 feedforward structure. We demonstrate with random dot stereograms that the V2 stage of our model is able to determine the location and the eye-of-origin of monocularly occluded regions and improve disparity map computation. We also examine a few related issues. First, we argue that since monocular regions are binocularly defined, they cannot generally be detected by monocular cells. Second, we show that our coarse-to-fine V1 model for conventional stereopsis explains double matching in Panum’s limiting case. This provides computational support to the notion that the perceived depth of a monocular bar next to a binocular rectangle may not be da Vinci stereopsis per se (Gillam et al., 2003). Third, we demonstrate that some stimuli previously deemed invalid have simple, valid geometric interpretations. Our work suggests that studies of da Vinci stereopsis should focus on stimuli more general than the bar-and-rectangle type and that disparity-boundary-selective V2 cells may provide a simple physiological mechanism for da Vinci stereopsis. PMID:17698163

  9. Randomized trials published in Chinese or Western journals: comparative empirical analysis.

    PubMed

    Purgato, Marianna; Cipriani, Andrea; Barbui, Corrado

    2012-06-01

    A major concern to the inclusion in systematic reviews of studies originating in China and published in Chinese journals refers to the quality of study reporting. In this systematic survey of randomized trials, we compared the characteristics of studies published in Chinese journals with those of studies published in Western journals. We included 69 studies comparing citalopram with other antidepressant drugs in the treatment of major depression. Of these, 37 (54%) were published in Chinese journals. The standard of reporting was generally poor in both Western and Chinese studies. In some Chinese studies, the generation of the randomization sequence raised concern about their experimental nature, and in almost all included studies, the concealment of allocation was not properly described. Blinding was seldom adopted in Chinese studies, and the risk of sponsorship bias was uncertain because Chinese studies did not report any financial support. In most Western studies, outcome data were selectively and incompletely reported. Pooling together all trials revealed that citalopram was similarly effective in comparison with all other antidepressant drugs both in Western studies (standardized mean difference, -0.04; 95% confidence interval, -0.15 to 0.06) and in Chinese studies (standardized mean difference, -0.08, 95% confidence interval, -0.18 to 0.02). Randomized controlled trials published in Chinese journals represent most of the studies included in this review. This suggests that omitting to search biomedical databases originating from China would systematically exclude a relevant proportion of randomized trials published in Chinese journals, with a risk of random error or bias. The increasing inclusion of Chinese studies in systematic reviews reinforces the need to check the quality of randomized trials that are meta-analyzed.

  10. Kin groups and trait groups: population structure and epidemic disease selection.

    PubMed

    Fix, A G

    1984-10-01

    A Monte Carlo simulation based on the population structure of a small-scale human population, the Semai Senoi of Malaysia, has been developed to study the combined effects of group, kin, and individual selection. The population structure resembles D.S. Wilson's structured deme model in that local breeding populations (Semai settlements) are subdivided into trait groups (hamlets) that may be kin-structured and are not themselves demes. Additionally, settlement breeding populations are connected by two-dimensional stepping-stone migration approaching 30% per generation. Group and kin-structured group selection occur among hamlets the survivors of which then disperse to breed within the settlement population. Genetic drift is modeled by the process of hamlet formation; individual selection as a deterministic process, and stepping-stone migration as either random or kin-structured migrant groups. The mechanism for group selection is epidemics of infectious disease that can wipe out small hamlets particularly if most adults become sick and social life collapses. Genetic resistance to a disease is an individual attribute; however, hamlet groups with several resistant adults are less likely to disintegrate and experience high social mortality. A specific human gene, hemoglobin E, which confers resistance to malaria, is studied as an example of the process. The results of the simulations show that high genetic variance among hamlet groups may be generated by moderate degrees of kin-structuring. This strong microdifferentiation provides the potential for group selection. The effect of group selection in this case is rapid increase in gene frequencies among the total set of populations. In fact, group selection in concert with individual selection produced a faster rate of gene frequency increase among a set of 25 populations than the rate within a single unstructured population subject to deterministic individual selection. Such rapid evolution with plausible rates of extinction, individual selection, and migration and a population structure realistic in its general form, has implications for specific human polymorphisms such as hemoglobin variants and for the more general problem of the tempo of evolution as well.

  11. The role of color and attention-to-color in mirror-symmetry perception.

    PubMed

    Gheorghiu, Elena; Kingdom, Frederick A A; Remkes, Aaron; Li, Hyung-Chul O; Rainville, Stéphane

    2016-07-11

    The role of color in the visual perception of mirror-symmetry is controversial. Some reports support the existence of color-selective mirror-symmetry channels, others that mirror-symmetry perception is merely sensitive to color-correlations across the symmetry axis. Here we test between the two ideas. Stimuli consisted of colored Gaussian-blobs arranged either mirror-symmetrically or quasi-randomly. We used four arrangements: (1) 'segregated' - symmetric blobs were of one color, random blobs of the other color(s); (2) 'random-segregated' - as above but with the symmetric color randomly selected on each trial; (3) 'non-segregated' - symmetric blobs were of all colors in equal proportions, as were the random blobs; (4) 'anti-symmetric' - symmetric blobs were of opposite-color across the symmetry axis. We found: (a) near-chance levels for the anti-symmetric condition, suggesting that symmetry perception is sensitive to color-correlations across the symmetry axis; (b) similar performance for random-segregated and non-segregated conditions, giving no support to the idea that mirror-symmetry is color selective; (c) highest performance for the color-segregated condition, but only when the observer knew beforehand the symmetry color, suggesting that symmetry detection benefits from color-based attention. We conclude that mirror-symmetry detection mechanisms, while sensitive to color-correlations across the symmetry axis and subject to the benefits of attention-to-color, are not color selective.

  12. The role of color and attention-to-color in mirror-symmetry perception

    PubMed Central

    Gheorghiu, Elena; Kingdom, Frederick A. A.; Remkes, Aaron; Li, Hyung-Chul O.; Rainville, Stéphane

    2016-01-01

    The role of color in the visual perception of mirror-symmetry is controversial. Some reports support the existence of color-selective mirror-symmetry channels, others that mirror-symmetry perception is merely sensitive to color-correlations across the symmetry axis. Here we test between the two ideas. Stimuli consisted of colored Gaussian-blobs arranged either mirror-symmetrically or quasi-randomly. We used four arrangements: (1) ‘segregated’ – symmetric blobs were of one color, random blobs of the other color(s); (2) ‘random-segregated’ – as above but with the symmetric color randomly selected on each trial; (3) ‘non-segregated’ – symmetric blobs were of all colors in equal proportions, as were the random blobs; (4) ‘anti-symmetric’ – symmetric blobs were of opposite-color across the symmetry axis. We found: (a) near-chance levels for the anti-symmetric condition, suggesting that symmetry perception is sensitive to color-correlations across the symmetry axis; (b) similar performance for random-segregated and non-segregated conditions, giving no support to the idea that mirror-symmetry is color selective; (c) highest performance for the color-segregated condition, but only when the observer knew beforehand the symmetry color, suggesting that symmetry detection benefits from color-based attention. We conclude that mirror-symmetry detection mechanisms, while sensitive to color-correlations across the symmetry axis and subject to the benefits of attention-to-color, are not color selective. PMID:27404804

  13. Ensemble Feature Learning of Genomic Data Using Support Vector Machine

    PubMed Central

    Anaissi, Ali; Goyal, Madhu; Catchpoole, Daniel R.; Braytee, Ali; Kennedy, Paul J.

    2016-01-01

    The identification of a subset of genes having the ability to capture the necessary information to distinguish classes of patients is crucial in bioinformatics applications. Ensemble and bagging methods have been shown to work effectively in the process of gene selection and classification. Testament to that is random forest which combines random decision trees with bagging to improve overall feature selection and classification accuracy. Surprisingly, the adoption of these methods in support vector machines has only recently received attention but mostly on classification not gene selection. This paper introduces an ensemble SVM-Recursive Feature Elimination (ESVM-RFE) for gene selection that follows the concepts of ensemble and bagging used in random forest but adopts the backward elimination strategy which is the rationale of RFE algorithm. The rationale behind this is, building ensemble SVM models using randomly drawn bootstrap samples from the training set, will produce different feature rankings which will be subsequently aggregated as one feature ranking. As a result, the decision for elimination of features is based upon the ranking of multiple SVM models instead of choosing one particular model. Moreover, this approach will address the problem of imbalanced datasets by constructing a nearly balanced bootstrap sample. Our experiments show that ESVM-RFE for gene selection substantially increased the classification performance on five microarray datasets compared to state-of-the-art methods. Experiments on the childhood leukaemia dataset show that an average 9% better accuracy is achieved by ESVM-RFE over SVM-RFE, and 5% over random forest based approach. The selected genes by the ESVM-RFE algorithm were further explored with Singular Value Decomposition (SVD) which reveals significant clusters with the selected data. PMID:27304923

  14. Augmenting Microarray Data with Literature-Based Knowledge to Enhance Gene Regulatory Network Inference

    PubMed Central

    Kilicoglu, Halil; Shin, Dongwook; Rindflesch, Thomas C.

    2014-01-01

    Gene regulatory networks are a crucial aspect of systems biology in describing molecular mechanisms of the cell. Various computational models rely on random gene selection to infer such networks from microarray data. While incorporation of prior knowledge into data analysis has been deemed important, in practice, it has generally been limited to referencing genes in probe sets and using curated knowledge bases. We investigate the impact of augmenting microarray data with semantic relations automatically extracted from the literature, with the view that relations encoding gene/protein interactions eliminate the need for random selection of components in non-exhaustive approaches, producing a more accurate model of cellular behavior. A genetic algorithm is then used to optimize the strength of interactions using microarray data and an artificial neural network fitness function. The result is a directed and weighted network providing the individual contribution of each gene to its target. For testing, we used invasive ductile carcinoma of the breast to query the literature and a microarray set containing gene expression changes in these cells over several time points. Our model demonstrates significantly better fitness than the state-of-the-art model, which relies on an initial random selection of genes. Comparison to the component pathways of the KEGG Pathways in Cancer map reveals that the resulting networks contain both known and novel relationships. The p53 pathway results were manually validated in the literature. 60% of non-KEGG relationships were supported (74% for highly weighted interactions). The method was then applied to yeast data and our model again outperformed the comparison model. Our results demonstrate the advantage of combining gene interactions extracted from the literature in the form of semantic relations with microarray analysis in generating contribution-weighted gene regulatory networks. This methodology can make a significant contribution to understanding the complex interactions involved in cellular behavior and molecular physiology. PMID:24921649

  15. Augmenting microarray data with literature-based knowledge to enhance gene regulatory network inference.

    PubMed

    Chen, Guocai; Cairelli, Michael J; Kilicoglu, Halil; Shin, Dongwook; Rindflesch, Thomas C

    2014-06-01

    Gene regulatory networks are a crucial aspect of systems biology in describing molecular mechanisms of the cell. Various computational models rely on random gene selection to infer such networks from microarray data. While incorporation of prior knowledge into data analysis has been deemed important, in practice, it has generally been limited to referencing genes in probe sets and using curated knowledge bases. We investigate the impact of augmenting microarray data with semantic relations automatically extracted from the literature, with the view that relations encoding gene/protein interactions eliminate the need for random selection of components in non-exhaustive approaches, producing a more accurate model of cellular behavior. A genetic algorithm is then used to optimize the strength of interactions using microarray data and an artificial neural network fitness function. The result is a directed and weighted network providing the individual contribution of each gene to its target. For testing, we used invasive ductile carcinoma of the breast to query the literature and a microarray set containing gene expression changes in these cells over several time points. Our model demonstrates significantly better fitness than the state-of-the-art model, which relies on an initial random selection of genes. Comparison to the component pathways of the KEGG Pathways in Cancer map reveals that the resulting networks contain both known and novel relationships. The p53 pathway results were manually validated in the literature. 60% of non-KEGG relationships were supported (74% for highly weighted interactions). The method was then applied to yeast data and our model again outperformed the comparison model. Our results demonstrate the advantage of combining gene interactions extracted from the literature in the form of semantic relations with microarray analysis in generating contribution-weighted gene regulatory networks. This methodology can make a significant contribution to understanding the complex interactions involved in cellular behavior and molecular physiology.

  16. Vitamin-Fortified Snack Food May Lead Consumers to Make Poor Dietary Decisions.

    PubMed

    Verrill, Linda; Wood, Dallas; Cates, Sheryl; Lando, Amy; Zhang, Yuanting

    2017-03-01

    The US Food and Drug Administration's (FDA's) fortification policy discourages the fortification of certain foods, including sugars and snack foods such as cookies, candies, cakes, chips, and carbonated beverages, yet manufacturers sometimes add vitamins and minerals to snack foods. To assess whether vitamin-fortified snack foods affect consumers' information-seeking, purchase decisions, and product-related health perceptions. For this experimental study, participants were randomly assigned to study conditions to compare products that varied in product type, nutrition profile, and fortification and nutrient claim status. Data were collected via an online consumer panel. US adults aged 18 years and older were randomly selected from Research Now's e-panel online household panel. Data were collected during fall 2014 (N=5,076). Participants were randomly assigned to one of 24 conditions: two products (vegetable chip/potato chip), two nutrition profiles (healthier/less healthy), two fortification scenarios (not fortified/fortified), and three nutrient claim conditions (two no claim/one with claim). The design was not balanced; claims were not shown on products that were not vitamin fortified. Outcome measures were information-seeking (viewed the Nutrition Facts label), purchase decisions, perception of product healthfulness, and correct selection of product with the healthier nutrient profile. Logistic regression was used to test all models. Analyses was adjusted for general label use, consumes product, health status, age, sex, level of education, presence of children in the household, and race/ethnicity. When the snack food carried a nutrient claim for vitamin fortification, participants were 1) less likely to look for nutrition information on the Nutrition Facts label, 2) more likely to select the product for purchase, 3) more likely to perceive the product as healthier, and 4) less likely to correctly choose the healthier product. Snack foods that have been vitamin-fortified may cause consumers to make poor dietary decisions. Copyright © 2017 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  17. Exercise Training and Recreational Activities to Promote Executive Functions in Chronic Stroke: A Proof-of-Concept Study

    PubMed Central

    Liu-Ambrose, Teresa; Eng, Janice J

    2015-01-01

    Background Stroke survivors represent a target population in need of intervention strategies to promote cognitive function and prevent dementia. Both exercise and recreational activities are promising strategies. We assessed the effect of a six-month exercise and recreation program on executive functions in adults with chronic stroke. Methods A six-month ancillary study within a multi-centre randomized trial. Twenty-eight chronic stroke survivors (i.e., ≥ 12 months since an index stroke) were randomized to one of two experimental groups: intervention (INT; n=12) or delayed intervention (D-INT; n=16). Participants of the INT group received a six-month community-based structured program that included two sessions of exercise training and one session of recreation and leisure activities per week. Participants of the D-INT group received usual care. The primary outcome measure was the Stroop Test, a cognitive test of selective attention and conflict resolution. Secondary cognitive measures included set shifting and working memory. Mood, functional capacity, and general balance and mobility were additional secondary outcome measures. Results Compared with the D-INT group, the INT group significantly improved selective attention and conflict resolution (p=0.02), working memory (p=0.04), and functional capacity (p=0.02) at the end of the six-month intervention period. Improved selective attention and conflict resolution was significantly associated with functional capacity at six months (r=0.39; p=0.04). Conclusions This is the first randomized study to demonstrate that an exercise and recreation program can significantly benefit executive functions in community-dwelling chronic stroke survivors who are mildly cognitively impaired – a population at high-risk for dementia and functional decline. Thus, clinicians should consider prescribing exercise and recreational activities in the cognitive rehabilitation of chronic stroke survivors. Clinical Trial Registration http://clinicaltrials.gov. Unique identifier: NCT01085240. PMID:25440324

  18. Randomization Methods in Emergency Setting Trials: A Descriptive Review

    ERIC Educational Resources Information Center

    Corbett, Mark Stephen; Moe-Byrne, Thirimon; Oddie, Sam; McGuire, William

    2016-01-01

    Background: Quasi-randomization might expedite recruitment into trials in emergency care settings but may also introduce selection bias. Methods: We searched the Cochrane Library and other databases for systematic reviews of interventions in emergency medicine or urgent care settings. We assessed selection bias (baseline imbalances) in prognostic…

  19. Middle Level Practices in European International and Department of Defense Schools.

    ERIC Educational Resources Information Center

    Waggoner, V. Christine; McEwin, C. Kenneth

    1993-01-01

    Discusses results of a 1989-90 survey of 70 randomly selected international schools and 70 randomly selected Department of Defense Schools in Europe. Programs and practices surveyed included enrollments, grade organization, curriculum and instructional plans, core subjects, grouping patterns, exploratory courses, advisory programs, and scheduling.…

  20. Variable selection with random forest: Balancing stability, performance, and interpretation in ecological and environmental modeling

    EPA Science Inventory

    Random forest (RF) is popular in ecological and environmental modeling, in part, because of its insensitivity to correlated predictors and resistance to overfitting. Although variable selection has been proposed to improve both performance and interpretation of RF models, it is u...

  1. Hebbian Learning in a Random Network Captures Selectivity Properties of the Prefrontal Cortex.

    PubMed

    Lindsay, Grace W; Rigotti, Mattia; Warden, Melissa R; Miller, Earl K; Fusi, Stefano

    2017-11-08

    Complex cognitive behaviors, such as context-switching and rule-following, are thought to be supported by the prefrontal cortex (PFC). Neural activity in the PFC must thus be specialized to specific tasks while retaining flexibility. Nonlinear "mixed" selectivity is an important neurophysiological trait for enabling complex and context-dependent behaviors. Here we investigate (1) the extent to which the PFC exhibits computationally relevant properties, such as mixed selectivity, and (2) how such properties could arise via circuit mechanisms. We show that PFC cells recorded from male and female rhesus macaques during a complex task show a moderate level of specialization and structure that is not replicated by a model wherein cells receive random feedforward inputs. While random connectivity can be effective at generating mixed selectivity, the data show significantly more mixed selectivity than predicted by a model with otherwise matched parameters. A simple Hebbian learning rule applied to the random connectivity, however, increases mixed selectivity and enables the model to match the data more accurately. To explain how learning achieves this, we provide analysis along with a clear geometric interpretation of the impact of learning on selectivity. After learning, the model also matches the data on measures of noise, response density, clustering, and the distribution of selectivities. Of two styles of Hebbian learning tested, the simpler and more biologically plausible option better matches the data. These modeling results provide clues about how neural properties important for cognition can arise in a circuit and make clear experimental predictions regarding how various measures of selectivity would evolve during animal training. SIGNIFICANCE STATEMENT The prefrontal cortex is a brain region believed to support the ability of animals to engage in complex behavior. How neurons in this area respond to stimuli-and in particular, to combinations of stimuli ("mixed selectivity")-is a topic of interest. Even though models with random feedforward connectivity are capable of creating computationally relevant mixed selectivity, such a model does not match the levels of mixed selectivity seen in the data analyzed in this study. Adding simple Hebbian learning to the model increases mixed selectivity to the correct level and makes the model match the data on several other relevant measures. This study thus offers predictions on how mixed selectivity and other properties evolve with training. Copyright © 2017 the authors 0270-6474/17/3711021-16$15.00/0.

  2. The relationship between blood viscosity and blood pressure in a random sample of the population aged 55 to 74 years.

    PubMed

    Fowkes, F G; Lowe, G D; Rumley, A; Lennie, S E; Smith, F B; Donnan, P T

    1993-05-01

    Blood viscosity is elevated in hypertensive subjects, but the association of viscosity with arterial blood pressure in the general population, and the influence of social, lifestyle and disease characteristics on this association, are not established. In the Edinburgh Artery Study, 1592 men and women aged 55-74 years selected randomly from the general population attended a university clinic. A fasting blood sample was taken for the measurement of blood viscosity and its major determinants (haematocrit, plasma viscosity and fibrinogen). Systolic pressure was related univariately to blood viscosity (P < 0.001), plasma viscosity (P < 0.001) and plasma fibrinogen (P < 0.01), but the association with fibrinogen did not persist after adjusting for body mass index. Diastolic pressure was related univariately to blood viscosity (P < 0.001) and plasma viscosity (P < 0.001) and haematocrit (P < 0.001) but not to fibrinogen. The only difference between the sexes was that the association between blood viscosity and systolic pressure was confined to males. Blood viscosity was associated equally with systolic and diastolic pressures in males, and remained independently related on multivariate analysis adjusting for age, sex, body mass index, social class, smoking, alcohol intake, exercise, angina, HDL and non-HDL cholesterol, diabetes mellitus, plasma viscosity, fibrinogen, and haematocrit.

  3. Calibration of Discrete Random Walk (DRW) Model via G.I Taylor's Dispersion Theory

    NASA Astrophysics Data System (ADS)

    Javaherchi, Teymour; Aliseda, Alberto

    2012-11-01

    Prediction of particle dispersion in turbulent flows is still an important challenge with many applications to environmental, as well as industrial, fluid mechanics. Several models of dispersion have been developed to predict particle trajectories and their relative velocities, in combination with a RANS-based simulation of the background flow. The interaction of the particles with the velocity fluctuations at different turbulent scales represents a significant difficulty in generalizing the models to the wide range of flows where they are used. We focus our attention on the Discrete Random Walk (DRW) model applied to flow in a channel, particularly to the selection of eddies lifetimes as realizations of a Poisson distribution with a mean value proportional to κ / ɛ . We present a general method to determine the constant of this proportionality by matching the DRW model dispersion predictions for fluid element and particle dispersion to G.I Taylor's classical dispersion theory. This model parameter is critical to the magnitude of predicted dispersion. A case study of its influence on sedimentation of suspended particles in a tidal channel with an array of Marine Hydrokinetic (MHK) turbines highlights the dependency of results on this time scale parameter. Support from US DOE through the Northwest National Marine Renewable Energy Center, a UW-OSU partnership.

  4. The Impact of Thai Family Matters on Parent/Adolescent Sexual Risk Communication Attitudes and Behaviors

    PubMed Central

    CUPP, PAMELA K.; ATWOOD, KATHARINE A.; BYRNES, HILARY F.; MILLER, BRENDA A.; FONGKAEW, WARUNEE; CHAMRATRITHIRONG, APHICHAT; RHUCHAROENPORNPANICH, ORRATAI; ROSATI, MICHAEL J.; CHOOKHARE, WARUNEE

    2014-01-01

    This article reports on a combined family-based substance abuse and HIV prevention intervention targeting families with children ages 13-14 in Bangkok, Thailand. Families (n=340) were randomly and proportionally selected from seven districts in Bangkok with half randomly assigned to an experimental or control condition. Families in the intervention condition were exposed to five interactive booklets about adolescent substance use and risky sexual behavior. Trained health educators followed up by phone to encourage completion of each booklet. Primary outcomes reported in this paper include whether the intervention increased the frequency of parent/child communication in general or about sexual risk taking in particular as well as whether the intervention reduced discomfort discussing sexual issues. We also tested to see if booklet completion was associated with communication outcomes at the 6-month follow-up. Multivariate findings indicate that the intervention significantly affected the frequency of general parent/child communication based on child reports. The intervention marginally affected frequency of parent/child communication about sexual issues based on parent reports. Booklet completion was associated with reduced discomfort discussing sex and was marginally associated with frequency of parent/child discussion of sex based on parent reports only. These findings indicate that a family-based program can have an impact on communication patterns. PMID:24094085

  5. From assessment to improvement of elderly care in general practice using decision support to increase adherence to ACOVE quality indicators: study protocol for randomized control trial

    PubMed Central

    2014-01-01

    Background Previous efforts such as Assessing Care of Vulnerable Elders (ACOVE) provide quality indicators for assessing the care of elderly patients, but thus far little has been done to leverage this knowledge to improve care for these patients. We describe a clinical decision support system to improve general practitioner (GP) adherence to ACOVE quality indicators and a protocol for investigating impact on GPs’ adherence to the rules. Design We propose two randomized controlled trials among a group of Dutch GP teams on adherence to ACOVE quality indicators. In both trials a clinical decision support system provides un-intrusive feedback appearing as a color-coded, dynamically updated, list of items needing attention. The first trial pertains to real-time automatically verifiable rules. The second trial concerns non-automatically verifiable rules (adherence cannot be established by the clinical decision support system itself, but the GPs report whether they will adhere to the rules). In both trials we will randomize teams of GPs caring for the same patients into two groups, A and B. For the automatically verifiable rules, group A GPs receive support only for a specific inter-related subset of rules, and group B GPs receive support only for the remainder of the rules. For non-automatically verifiable rules, group A GPs receive feedback framed as actions with positive consequences, and group B GPs receive feedback framed as inaction with negative consequences. GPs indicate whether they adhere to non-automatically verifiable rules. In both trials, the main outcome measure is mean adherence, automatically derived or self-reported, to the rules. Discussion We relied on active end-user involvement in selecting the rules to support, and on a model for providing feedback displayed as color-coded real-time messages concerning the patient visiting the GP at that time, without interrupting the GP’s workflow with pop-ups. While these aspects are believed to increase clinical decision support system acceptance and its impact on adherence to the selected clinical rules, systems with these properties have not yet been evaluated. Trial registration Controlled Trials NTR3566 PMID:24642339

  6. Potentially Inappropriate Prescribing to Older Patients: Criteria, Prevalence and an Intervention to Reduce it: The Prescription Peer Academic Detailing (Rx-PAD) Study - A Cluster-Randomized, Educational Intervention in Norwegian General Practice.

    PubMed

    Rognstad, Sture; Brekke, Mette; Gjelstad, Svein; Straand, Jørund; Fetveit, Arne

    2018-05-12

    Potentially Inappropriate Prescriptions (PIP) is drug treatment, which in general, at the group level for a median/mean patient, can be considered unfavorable meaning that the risks commonly may outweigh the benefits. This MiniReview reports and discusses the main findings in a large cluster-randomized educational intervention in Norwegian general practice, aimed at reducing the prevalence of PIPs to patients ≥ 70 years (The Rx-PAD study). Targets for the intervention were general practitioners (GPs) in continuing medical education (CME) groups receiving educational outreach visits (i.e., peer academic detailing). A Delphi consensus process, with a panel of medical experts was undertaken to elaborate a list of explicit criteria defining PIPs for patients ≥ 70 years in general practice. Agreement was achieved for 36 explicit PIP criteria, the so-called Norwegian General Practice (NorGeP) criteria. Using a selection (n = 24) of these criteria during a one-year baseline period on the prescribing practice of 454 GPs (i.e., those enrolled to participate in the intervention trial), we found a prevalence rate of 24.7 PIPs per 100 patients ≥70 years per year. In the Rx-PAD study, 449 GPs completed an educational intervention (96.6% of the included GPs), 250 in the intervention group and 199 in the control arm. Following the intervention, PIPs were reduced by 13% (95% CI 8.6 - 17.3), and the number of patients who were no longer exposed to one or more PIPs was reduced by 1173 (8.1%). The GPs who responded most strongly to the educational intervention were the oldest GPs (57-68 years) and these were the GPs with the highest prevalence of PIPs at baseline before the intervention. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Comparison of Address-based Sampling and Random-digit Dialing Methods for Recruiting Young Men as Controls in a Case-Control Study of Testicular Cancer Susceptibility

    PubMed Central

    Clagett, Bartholt; Nathanson, Katherine L.; Ciosek, Stephanie L.; McDermoth, Monique; Vaughn, David J.; Mitra, Nandita; Weiss, Andrew; Martonik, Rachel; Kanetsky, Peter A.

    2013-01-01

    Random-digit dialing (RDD) using landline telephone numbers is the historical gold standard for control recruitment in population-based epidemiologic research. However, increasing cell-phone usage and diminishing response rates suggest that the effectiveness of RDD in recruiting a random sample of the general population, particularly for younger target populations, is decreasing. In this study, we compared landline RDD with alternative methods of control recruitment, including RDD using cell-phone numbers and address-based sampling (ABS), to recruit primarily white men aged 18–55 years into a study of testicular cancer susceptibility conducted in the Philadelphia, Pennsylvania, metropolitan area between 2009 and 2012. With few exceptions, eligible and enrolled controls recruited by means of RDD and ABS were similar with regard to characteristics for which data were collected on the screening survey. While we find ABS to be a comparably effective method of recruiting young males compared with landline RDD, we acknowledge the potential impact that selection bias may have had on our results because of poor overall response rates, which ranged from 11.4% for landline RDD to 1.7% for ABS. PMID:24008901

  8. Clinical and microbiologic effects of commercially available dentifrice containing aloe vera: a randomized controlled clinical trial.

    PubMed

    Pradeep, A R; Agarwal, Esha; Naik, Savitha B

    2012-06-01

    Certain plants used in folk medicine serve as a source of therapeutic agents that have antimicrobial and other multipotential effects. This prospective, randomized, placebo, and positively controlled clinical trial was designed to evaluate the clinical and microbiologic effects of a commercially available dentifrice containing aloe vera on the reduction of plaque and gingival inflammation in patients with gingivitis. Ninety patients diagnosed with chronic generalized gingivitis were selected and randomly divided into three groups: group 1, placebo toothpaste; group 2, toothpaste containing aloe vera; and group 3, toothpaste with polymer and fluoride containing triclosan. Clinical evaluation was undertaken using a gingival index, plaque was assessed using a modification of the Quigley-Hein index, and microbiologic counts were assessed at baseline, 6 weeks, 12 weeks, and 24 weeks. A subjective evaluation was also undertaken by questionnaire. Toothpaste containing aloe vera showed significant improvement in gingival and plaque index scores as well as microbiologic counts compared with placebo dentifrice. These improvements were comparable to those achieved with toothpaste containing triclosan. Toothpaste containing aloe vera may be a useful herbal formulation for chemical plaque control agents and improvement in plaque and gingival status.

  9. Generalizing Evidence From Randomized Clinical Trials to Target Populations

    PubMed Central

    Cole, Stephen R.; Stuart, Elizabeth A.

    2010-01-01

    Properly planned and conducted randomized clinical trials remain susceptible to a lack of external validity. The authors illustrate a model-based method to standardize observed trial results to a specified target population using a seminal human immunodeficiency virus (HIV) treatment trial, and they provide Monte Carlo simulation evidence supporting the method. The example trial enrolled 1,156 HIV-infected adult men and women in the United States in 1996, randomly assigned 577 to a highly active antiretroviral therapy and 579 to a largely ineffective combination therapy, and followed participants for 52 weeks. The target population was US people infected with HIV in 2006, as estimated by the Centers for Disease Control and Prevention. Results from the trial apply, albeit muted by 12%, to the target population, under the assumption that the authors have measured and correctly modeled the determinants of selection that reflect heterogeneity in the treatment effect. In simulations with a heterogeneous treatment effect, a conventional intent-to-treat estimate was biased with poor confidence limit coverage, but the proposed estimate was largely unbiased with appropriate confidence limit coverage. The proposed method standardizes observed trial results to a specified target population and thereby provides information regarding the generalizability of trial results. PMID:20547574

  10. Analysis of landslide hazard area in Ludian earthquake based on Random Forests

    NASA Astrophysics Data System (ADS)

    Xie, J.-C.; Liu, R.; Li, H.-W.; Lai, Z.-L.

    2015-04-01

    With the development of machine learning theory, more and more algorithms are evaluated for seismic landslides. After the Ludian earthquake, the research team combine with the special geological structure in Ludian area and the seismic filed exploration results, selecting SLOPE(PODU); River distance(HL); Fault distance(DC); Seismic Intensity(LD) and Digital Elevation Model(DEM), the normalized difference vegetation index(NDVI) which based on remote sensing images as evaluation factors. But the relationships among these factors are fuzzy, there also exists heavy noise and high-dimensional, we introduce the random forest algorithm to tolerate these difficulties and get the evaluation result of Ludian landslide areas, in order to verify the accuracy of the result, using the ROC graphs for the result evaluation standard, AUC covers an area of 0.918, meanwhile, the random forest's generalization error rate decreases with the increase of the classification tree to the ideal 0.08 by using Out Of Bag(OOB) Estimation. Studying the final landslides inversion results, paper comes to a statistical conclusion that near 80% of the whole landslides and dilapidations are in areas with high susceptibility and moderate susceptibility, showing the forecast results are reasonable and adopted.

  11. Monitoring of Leuconostoc mesenteroides DRC starter in fermented vegetable by random integration of chloramphenicol acetyltransferase gene.

    PubMed

    Eom, Hyun-Ju; Park, Joong Min; Seo, Min Jae; Kim, Myoung-Dong; Han, Nam Soo

    2008-09-01

    In 2004, Leuconostoc mesenteroides DRC was first used as a starter culture for achieving higher organoleptic effects in Korean kimchi manufacture. For a better understanding of starter growth in a mixed culture system, and for predicting starter predominance in kimchi, a monitoring system for the starter was established. The chloramphenicol resistance marker gene (cat) was randomly integrated into chromosomal DNA of L. mesenteroides DRC using a viral transposon and transposase. The DRC mutant, tDRC2, had a similar growth pattern to the host strain, with no major alteration in phenotypic characteristics. The mutant strain was inoculated into real kimchi, and monitoring of the starter population was successfully achieved. The overall predominance of Leuconostoc in kimchi inoculated with DRC followed the general growth pattern of this genus during kimchi fermentation. Our results also demonstrate the competitive ability of the DRC starter against Leuconostoc from natural flora, maintaining its predominance above 88% during the whole fermentation period. Based on this experiment, the random gene integration method using a transposon was shown to be of utility in transferring any commercial starter into a selectable and monitorable strain for simulation purposes.

  12. Reliability of N-terminal proBNP assay in diagnosis of left ventricular systolic dysfunction within representative and high risk populations.

    PubMed

    Hobbs, F D R; Davis, R C; Roalfe, A K; Hare, R; Davies, M K

    2004-08-01

    To determine the performance of a new NT-proBNP assay in comparison with brain natriuretic peptide (BNP) in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populations. Blood samples were taken prospectively in the community from 591 randomly sampled individuals over the age of 45 years, stratified for age and socioeconomic status and divided into four cohorts (general population; clinically diagnosed heart failure; patients on diuretics; and patients deemed at high risk of heart failure). Definite heart failure (left ventricular ejection fraction (LVEF) < 40%) was identified in 33 people. Samples were handled as though in routine clinical practice. The laboratories undertaking the assays were blinded. Using NT-proBNP to diagnose LVEF < 40% in the general population, a level of > 40 pmol/l had 80% sensitivity, 73% specificity, 5% positive predictive value (PPV), 100% negative predictive value (NPV), and an area under the receiver-operator characteristic curve (AUC) of 76% (95% confidence interval (CI) 46% to 100%). For BNP to diagnose LVSD, a cut off level of > 33 pmol/l had 80% sensitivity, 88% specificity, 10% PPV, 100% NPV, and AUC of 88% (95% CI 75% to 100%). Similar NPVs were found for patients randomly screened from the three other populations. Both NT-proBNP and BNP have value in diagnosing LVSD in a community setting, with similar sensitivities and specificities. Using a high cut off for positivity will confirm the diagnosis of LVSD but will miss cases. At lower cut off values, positive results will require cardiac imaging to confirm LVSD.

  13. Effect of a toothpaste containing triclosan, cetylpyridinium chloride, and essential oils on gingival status in schoolchildren: a randomized clinical pilot study.

    PubMed

    Cagetti, Maria Grazia; Strohmenger, Laura; Basile, Valentina; Abati, Silvio; Mastroberardino, Stefano; Campus, Guglielmo

    2015-05-01

    This randomized double-blind in vivo pilot study has evaluated the effects of a toothpaste containing fluoride (control) versus toothpaste containing fluoride, triclosan, cetylpyridinium chloride and essential oils (experimental) in controlling supragingival dental plaque and bleeding on probing in a sample of healthy schoolchildren. In total, 48 children (8 to 10 years) were selected and randomly divided into two groups (experimental and control), using the two different toothpastes twice a day for 2 minutes each for a 4-week period. The investigation included an evaluation of plaque quantity, using the Turesky modified Quigley-Hein method, and bleeding on probing that was recorded dichotomously. The unit of analysis was set at the gingival site level. Plaque Index and bleeding on probing were analyzed using distribution tables and chi-square test. A generalized estimating equation was used to estimate the parameters of a generalized linear model with a possible unknown correlation between outcomes. In total, 40 schoolchildren completed the trial. Considering each group separately, a statistically significant difference in plaque scores was recorded for both treatments (z-test = 9.23, P < .01 for the experimental toothpaste; and z-test = 7.47, P < .01 for the control toothpaste). Nevertheless, the effect over time was higher for the experimental toothpaste than for the control one (3.38 vs 1.96). No statistically significant results were observed regarding bleeding on probing. The 4-week use of the experimental toothpaste seems to produce higher plaque reduction compared to fluoridated toothpaste without other antibacterial ingredients. This finding has to be confirmed in a larger study.

  14. Achieving involvement: process outcomes from a cluster randomized trial of shared decision making skill development and use of risk communication aids in general practice.

    PubMed

    Elwyn, G; Edwards, A; Hood, K; Robling, M; Atwell, C; Russell, I; Wensing, M; Grol, R

    2004-08-01

    A consulting method known as 'shared decision making' (SDM) has been described and operationalized in terms of several 'competences'. One of these competences concerns the discussion of the risks and benefits of treatment or care options-'risk communication'. Few data exist on clinicians' ability to acquire skills and implement the competences of SDM or risk communication in consultations with patients. The aims of this study were to evaluate the effects of skill development workshops for SDM and the use of risk communication aids on the process of consultations. A cluster randomized trial with crossover was carried out with the participation of 20 recently qualified GPs in urban and rural general practices in Gwent, South Wales. A total of 747 patients with known atrial fibrillation, prostatism, menorrhagia or menopausal symptoms were invited to a consultation to review their condition or treatments. Half the consultations were randomly selected for audio-taping, of which 352 patients attended and were audio-taped successfully. After baseline, participating doctors were randomized to receive training in (i) SDM skills or (ii) the use of simple risk communication aids, using simulated patients. The alternative training was then provided for the final study phase. Patients were allocated randomly to a consultation during baseline or intervention 1 (SDM or risk communication aids) or intervention 2 phases. A randomly selected half of the consultations were audio-taped from each phase. Raters (independent, trained and blinded to study phase) assessed the audio-tapes using a validated scale to assess levels of patient involvement (OPTION: observing patient involvement), and to analyse the nature of risk information discussed. Clinicians completed questionnaires after each consultation, assessing perceived clinician-patient agreement and level of patient involvement in decisions. Multilevel modelling was carried out with the OPTION score as the dependent variable, and rater, consultation and clinician levels of data, standardized by rater within clinician. Following each of the interventions, the clinicians significantly increased their involvement of patients in decision making (OPTION score increased by 10.6 following risk communication training [95% confidence interval (CI) 7.9 -13.3; P < 0.001] and by 12.9 after SDM skill development (95% CI 10 -15.8, P < 0.001), a moderate effect size. The level of involvement achieved by the risk communication aids was significantly increased by the subsequent introduction of the skill development workshops (7.7 increase in OPTION score, 95% CI 3.4-12; P < 0.001). The alternative sequence (skills followed by risk communication aids) did not achieve this effect. The use of most risk information formats increased after the provision of specific risk communication aids (P < 0.001). Clinicians using the risk communication tools perceived significantly higher patient and clinician agreement on treatment (P < 0.001), patient satisfaction with information (P < 0.01), clinician satisfaction with decision (P < 0.01) and general overall satisfaction with the consultation (P < 0.001) than those who were exposed to SDM skill development workshops. These clinicians were able to acquire the skills to implement SDM competences and to use risk communication aids. Each intervention provided independent effects. Further progress towards greater patient involvement in health care decision making is possible, and skill development in this area should be incorporated into postgraduate professional development programmes.

  15. On Probability Domains IV

    NASA Astrophysics Data System (ADS)

    Frič, Roman; Papčo, Martin

    2017-12-01

    Stressing a categorical approach, we continue our study of fuzzified domains of probability, in which classical random events are replaced by measurable fuzzy random events. In operational probability theory (S. Bugajski) classical random variables are replaced by statistical maps (generalized distribution maps induced by random variables) and in fuzzy probability theory (S. Gudder) the central role is played by observables (maps between probability domains). We show that to each of the two generalized probability theories there corresponds a suitable category and the two resulting categories are dually equivalent. Statistical maps and observables become morphisms. A statistical map can send a degenerated (pure) state to a non-degenerated one —a quantum phenomenon and, dually, an observable can map a crisp random event to a genuine fuzzy random event —a fuzzy phenomenon. The dual equivalence means that the operational probability theory and the fuzzy probability theory coincide and the resulting generalized probability theory has two dual aspects: quantum and fuzzy. We close with some notes on products and coproducts in the dual categories.

  16. Adaptive Electronic Camouflage Using Texture Synthesis

    DTIC Science & Technology

    2012-04-01

    algorithm begins by computing the GLCMs, GIN and GOUT , of the input image (e.g., image of local environment) and output image (randomly generated...respectively. The algorithm randomly selects a pixel from the output image and cycles its gray-level through all values. For each value, GOUT is updated...The value of the selected pixel is permanently changed to the gray-level value that minimizes the error between GIN and GOUT . Without selecting a

  17. Input Decimated Ensembles

    NASA Technical Reports Server (NTRS)

    Tumer, Kagan; Oza, Nikunj C.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    Using an ensemble of classifiers instead of a single classifier has been shown to improve generalization performance in many pattern recognition problems. However, the extent of such improvement depends greatly on the amount of correlation among the errors of the base classifiers. Therefore, reducing those correlations while keeping the classifiers' performance levels high is an important area of research. In this article, we explore input decimation (ID), a method which selects feature subsets for their ability to discriminate among the classes and uses them to decouple the base classifiers. We provide a summary of the theoretical benefits of correlation reduction, along with results of our method on two underwater sonar data sets, three benchmarks from the Probenl/UCI repositories, and two synthetic data sets. The results indicate that input decimated ensembles (IDEs) outperform ensembles whose base classifiers use all the input features; randomly selected subsets of features; and features created using principal components analysis, on a wide range of domains.

  18. Impact assessment and decontamination of pesticides from meat under different culinary processes.

    PubMed

    Sengupta, Dwaipayan; Aktar, Md Wasim; Alam, Samsul; Chowdhury, Ashim

    2010-10-01

    A total of 75 animals between 1.5 and 8 years old were randomly selected for the study. Of these, 57.8% were cross-bred animals and the rest were non-descript. Moreover, 61.8% of the animals under study were brought for slaughter from local sources and the rest from farm houses. Samples collected from five districts revealed contamination with traces of organochlorine pesticides (0.01-0.22 microg g(-1)) and organophosphorus pesticides (0.111-0.098 microg g(-1)). In general, all the raw meat samples possessed dichlorodiphenyltrichloroethane at the highest level. Contamination was highest in cow meat samples and lowest in chicken samples. No particular district-wise trend was obtained for the pesticides selected for analysis. Subsequent decontamination study revealed that cooking is the best option in reducing pesticide load in raw meat samples. Cooked chicken is the safest foodstuff for consumption.

  19. Selection of specific interactors from phage display library based on sea lamprey variable lymphocyte receptor sequences.

    PubMed

    Wezner-Ptasinska, Magdalena; Otlewski, Jacek

    2015-12-01

    Variable lymphocyte receptors (VLRs) are non-immunoglobulin components of adaptive immunity in jawless vertebrates. These proteins composed of leucine-rich repeat modules offer some advantages over antibodies in target binding and therefore are attractive candidates for biotechnological applications. In this paper we report the design and characterization of a phage display library based on a previously proposed dVLR scaffold containing six LRR modules [Wezner-Ptasinska et al., 2011]. Our library was designed based on a consensus approach in which the randomization scheme reflects the frequencies of amino acids naturally occurring in respective positions responsible for antigen recognition. We demonstrate general applicability of the scaffold by selecting dVLRs specific for lysozyme and S100A7 protein with KD values in the micromolar range. The dVLR library could be used as a convenient alternative to antibodies for effective isolation of high affinity binders.

  20. Visual evoked potentials and selective attention to points in space

    NASA Technical Reports Server (NTRS)

    Van Voorhis, S.; Hillyard, S. A.

    1977-01-01

    Visual evoked potentials (VEPs) were recorded to sequences of flashes delivered to the right and left visual fields while subjects responded promptly to designated stimuli in one field at a time (focused attention), in both fields at once (divided attention), or to neither field (passive). Three stimulus schedules were used: the first was a replication of a previous study (Eason, Harter, and White, 1969) where left- and right-field flashes were delivered quasi-independently, while in the other two the flashes were delivered to the two fields in random order (Bernoulli sequence). VEPs to attended-field stimuli were enhanced at both occipital (O2) and central (Cz) recording sites under all stimulus sequences, but different components were affected at the two scalp sites. It was suggested that the VEP at O2 may reflect modality-specific processing events, while the response at Cz, like its auditory homologue, may index more general aspects of selective attention.

  1. The mere exposure effect is differentially sensitive to different judgment tasks.

    PubMed

    Seamon, J G; McKenna, P A; Binder, N

    1998-03-01

    The mere exposure effect is the increase in positive affect that results from the repeated exposure to previously novel stimuli. We sought to determine if judgments other than affective preference could reliably produce a mere exposure effect for two-dimensional random shapes. In two experiments, we found that brighter and darker judgments did not differentiate target from distracter shapes, liking judgments led to target selection greater than chance, and disliking judgments led to distracter selection greater than chance. These results for brighter, darker, and liking judgments were obtained regardless of whether shape recognition was greater (Experiment 1) or not greater (Experiment 2) than chance. Effects of prior exposure to novel shapes were reliably observed only for affective judgment tasks. These results are inconsistent with general predictions made by the nonspecific activation hypothesis, but not the affective primacy or perceptual fluency hypotheses which were discussed in terms of cognitive neuroscience research. Copyright 1998 Academic Press.

  2. Hebbian Learning in a Random Network Captures Selectivity Properties of the Prefrontal Cortex

    PubMed Central

    Lindsay, Grace W.

    2017-01-01

    Complex cognitive behaviors, such as context-switching and rule-following, are thought to be supported by the prefrontal cortex (PFC). Neural activity in the PFC must thus be specialized to specific tasks while retaining flexibility. Nonlinear “mixed” selectivity is an important neurophysiological trait for enabling complex and context-dependent behaviors. Here we investigate (1) the extent to which the PFC exhibits computationally relevant properties, such as mixed selectivity, and (2) how such properties could arise via circuit mechanisms. We show that PFC cells recorded from male and female rhesus macaques during a complex task show a moderate level of specialization and structure that is not replicated by a model wherein cells receive random feedforward inputs. While random connectivity can be effective at generating mixed selectivity, the data show significantly more mixed selectivity than predicted by a model with otherwise matched parameters. A simple Hebbian learning rule applied to the random connectivity, however, increases mixed selectivity and enables the model to match the data more accurately. To explain how learning achieves this, we provide analysis along with a clear geometric interpretation of the impact of learning on selectivity. After learning, the model also matches the data on measures of noise, response density, clustering, and the distribution of selectivities. Of two styles of Hebbian learning tested, the simpler and more biologically plausible option better matches the data. These modeling results provide clues about how neural properties important for cognition can arise in a circuit and make clear experimental predictions regarding how various measures of selectivity would evolve during animal training. SIGNIFICANCE STATEMENT The prefrontal cortex is a brain region believed to support the ability of animals to engage in complex behavior. How neurons in this area respond to stimuli—and in particular, to combinations of stimuli (“mixed selectivity”)—is a topic of interest. Even though models with random feedforward connectivity are capable of creating computationally relevant mixed selectivity, such a model does not match the levels of mixed selectivity seen in the data analyzed in this study. Adding simple Hebbian learning to the model increases mixed selectivity to the correct level and makes the model match the data on several other relevant measures. This study thus offers predictions on how mixed selectivity and other properties evolve with training. PMID:28986463

  3. Unconventional therapies in asthma: an overview.

    PubMed

    Lewith, G T; Watkins, A D

    1996-11-01

    Acupuncture, homoeopathy, mind-body therapies, and nutritional, herbal, and environmental medicine have all been used in the management of patients with asthma. This paper reviews the evidence base for the use of these unconventional or complementary therapies. Although there is a paucity of large randomized, controlled trials in this area, there is sufficient evidence to suggest that many of these therapies can produce objective and subjective benefit in selected groups of patients. In view of the increasing popularity of complementary medicine among patients and general practitioners, there is now an urgent need for high-quality research to determine how, or whether, these therapies may be interwoven with the more orthodox treatments currently available.

  4. Human Centred Design Considerations for Connected Health Devices for the Older Adult

    PubMed Central

    Harte, Richard P.; Glynn, Liam G.; Broderick, Barry J.; Rodriguez-Molinero, Alejandro; Baker, Paul M. A.; McGuiness, Bernadette; O’Sullivan, Leonard; Diaz, Marta; Quinlan, Leo R.; ÓLaighin, Gearóid

    2014-01-01

    Connected health devices are generally designed for unsupervised use, by non-healthcare professionals, facilitating independent control of the individuals own healthcare. Older adults are major users of such devices and are a population significantly increasing in size. This group presents challenges due to the wide spectrum of capabilities and attitudes towards technology. The fit between capabilities of the user and demands of the device can be optimised in a process called Human Centred Design. Here we review examples of some connected health devices chosen by random selection, assess older adult known capabilities and attitudes and finally make analytical recommendations for design approaches and design specifications. PMID:25563225

  5. The Factors Associated with Suicide Ideation in Iranian Soldiers

    PubMed Central

    Majdian, Mohammad; Mirzamani, S. Mahmood

    2010-01-01

    Objective The study focuses on psychosocial variables related to suicide ideation in young soldiers. Method 1329 Soldiers were randomly selected from the Infantry Forces in different regions. All the soldiers were requested to complete the Beck Scale for Suicide Ideation (BSSI) as well as General Health Questionnaire (GHQ-28). Data were analyzed using correlation tests. Results The results revealed that psychological factors, negative family background, environmental and task-related problems, and sociodemographic problems were significantly associated with suicide ideation. Discussion Overall, suicide ideation could be prevented if soldiers with psychosocial problems were identified and the Army officials applied appropriate methods to solve these psychological problems. PMID:22952500

  6. Canine stage 1 periodontal disease: a latent pathology.

    PubMed

    Whyte, A; Bonastre, C; Monteagudo, L V; Les, F; Obon, J; Whyte, J; Tejedor, M T

    2014-07-01

    To evaluate the potential health issues associated with periodontal disease (PD) in dogs, 1004 teeth from 25 dogs were examined. The dogs were randomly selected, aged 2-14 years, and had at least 95% of their teeth at the first PD stage. Significant positive correlations between plaque grade (PG) and gum inflammation, gingival regression, periodontal pocket, age and serum alanine aminotransferase (ALT) activity were identified. In contrast, PG was negatively correlated to total platelet count. Altogether, these findings suggest that prevention and therapy at the first PD stages can have an important impact on the general health condition of dogs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. The Expected Sample Variance of Uncorrelated Random Variables with a Common Mean and Some Applications in Unbalanced Random Effects Models

    ERIC Educational Resources Information Center

    Vardeman, Stephen B.; Wendelberger, Joanne R.

    2005-01-01

    There is a little-known but very simple generalization of the standard result that for uncorrelated random variables with common mean [mu] and variance [sigma][superscript 2], the expected value of the sample variance is [sigma][superscript 2]. The generalization justifies the use of the usual standard error of the sample mean in possibly…

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

    PubMed

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

    2017-04-01

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

  9. How to Do Random Allocation (Randomization)

    PubMed Central

    Shin, Wonshik

    2014-01-01

    Purpose To explain the concept and procedure of random allocation as used in a randomized controlled study. Methods We explain the general concept of random allocation and demonstrate how to perform the procedure easily and how to report it in a paper. PMID:24605197

  10. RARtool: A MATLAB Software Package for Designing Response-Adaptive Randomized Clinical Trials with Time-to-Event Outcomes.

    PubMed

    Ryeznik, Yevgen; Sverdlov, Oleksandr; Wong, Weng Kee

    2015-08-01

    Response-adaptive randomization designs are becoming increasingly popular in clinical trial practice. In this paper, we present RARtool , a user interface software developed in MATLAB for designing response-adaptive randomized comparative clinical trials with censored time-to-event outcomes. The RARtool software can compute different types of optimal treatment allocation designs, and it can simulate response-adaptive randomization procedures targeting selected optimal allocations. Through simulations, an investigator can assess design characteristics under a variety of experimental scenarios and select the best procedure for practical implementation. We illustrate the utility of our RARtool software by redesigning a survival trial from the literature.

  11. Geriatric drug therapy and healthcare utilization in the United kingdom.

    PubMed

    Kennerfalk, Anita; Ruigómez, Ana; Wallander, Mari-Ann; Wilhelmsen, Lars; Johansson, Saga

    2002-05-01

    To describe the use of prescription drug therapy, especially polypharmacy, in an elderly general population; to relate that use to age, gender, and different types of healthcare utilization; and to investigate the influence of selection of different time windows on the result of the quantity as well as the categories of drugs used. Data on a sample of 5000 patients aged 65-90 years in 1996 were derived from the General Practice Research Database (GPRD). The population covered by GPRD is broadly representative of the UK population treated in general practice. Drug use was assessed using 2 time windows - current use of individual drugs on a random day (index date) and 1 month following the index date. Healthcare utilization was analyzed by use of information on visits to general practitioners (GPs), hospitalizations, and referrals to specialists. Women used more drugs than men; however, the prevalence of polypharmacy, defined as concomitant use of > or =5 drugs, was similar in both genders. The most frequently used therapeutic groups were cardiovascular, central nervous, and gastrointestinal system drugs. Almost 80% of both women and men visited a GP at least once a year. Overall, women used more ambulatory care services and men were hospitalized more often. Use of random date compared with 1-month period resulted in a significant underestimation of the amount of drugs used for acute conditions and, consequently, the risk of polypharmacy. The overall results confirm the findings in earlier studies suggesting that the GPRD might be a useful tool in further studies on prescription drug use among elderly persons. More information on the appropriateness of drug use is needed to prevent overuse as well as underuse of medications among the elderly.

  12. The Effect of CAI on Reading Achievement.

    ERIC Educational Resources Information Center

    Hardman, Regina

    A study determined whether computer assisted instruction (CAI) had an effect on students' reading achievement. Subjects were 21 randomly selected fourth-grade students at D. S. Wentworth Elementary School on the south side of Chicago in a low-income neighborhood who received a year's exposure to a CAI program, and 21 randomly selected students at…

  13. 78 FR 57033 - United States Standards for Condition of Food Containers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... containers during production. Stationary lot sampling is the process of randomly selecting sample units from.... * * * * * Stationary lot sampling. The process of randomly selecting sample units from a lot whose production has been... less than \\1/16\\-inch Stringy seal (excessive plastic threads showing at edge of seal 222 area...

  14. Access to Higher Education by the Luck of the Draw

    ERIC Educational Resources Information Center

    Stone, Peter

    2013-01-01

    Random selection is a fair way to break ties between applicants of equal merit seeking admission to institutions of higher education (with "merit" defined here in terms of the intrinsic contribution higher education would make to the applicant's life). Opponents of random selection commonly argue that differences in strength between…

  15. An Evaluation of Information Criteria Use for Correct Cross-Classified Random Effects Model Selection

    ERIC Educational Resources Information Center

    Beretvas, S. Natasha; Murphy, Daniel L.

    2013-01-01

    The authors assessed correct model identification rates of Akaike's information criterion (AIC), corrected criterion (AICC), consistent AIC (CAIC), Hannon and Quinn's information criterion (HQIC), and Bayesian information criterion (BIC) for selecting among cross-classified random effects models. Performance of default values for the 5…

  16. 1977 Survey of the American Professoriate. Technical Report.

    ERIC Educational Resources Information Center

    Ladd, Everett Carll, Jr.; And Others

    The development and data validation of the 1977 Ladd-Lipset national survey of the American professoriate are described. The respondents were selected from a random sample of colleges and universities and from a random sample of individual faculty members from the universities. The 158 institutions in the 1977 survey were selected from 2,406…

  17. Selection dynamic of Escherichia coli host in M13 combinatorial peptide phage display libraries.

    PubMed

    Zanconato, Stefano; Minervini, Giovanni; Poli, Irene; De Lucrezia, Davide

    2011-01-01

    Phage display relies on an iterative cycle of selection and amplification of random combinatorial libraries to enrich the initial population of those peptides that satisfy a priori chosen criteria. The effectiveness of any phage display protocol depends directly on library amino acid sequence diversity and the strength of the selection procedure. In this study we monitored the dynamics of the selective pressure exerted by the host organism on a random peptide library in the absence of any additional selection pressure. The results indicate that sequence censorship exerted by Escherichia coli dramatically reduces library diversity and can significantly impair phage display effectiveness.

  18. Fluorescence Excitation Spectroscopy for Phytoplankton Species Classification Using an All-Pairs Method: Characterization of a System with Unexpectedly Low Rank.

    PubMed

    Rekully, Cameron M; Faulkner, Stefan T; Lachenmyer, Eric M; Cunningham, Brady R; Shaw, Timothy J; Richardson, Tammi L; Myrick, Michael L

    2018-03-01

    An all-pairs method is used to analyze phytoplankton fluorescence excitation spectra. An initial set of nine phytoplankton species is analyzed in pairwise fashion to select two optical filter sets, and then the two filter sets are used to explore variations among a total of 31 species in a single-cell fluorescence imaging photometer. Results are presented in terms of pair analyses; we report that 411 of the 465 possible pairings of the larger group of 31 species can be distinguished using the initial nine-species-based selection of optical filters. A bootstrap analysis based on the larger data set shows that the distribution of possible pair separation results based on a randomly selected nine-species initial calibration set is strongly peaked in the 410-415 pair separation range, consistent with our experimental result. Further, the result for filter selection using all 31 species is also 411 pair separations; The set of phytoplankton fluorescence excitation spectra is intuitively high in rank due to the number and variety of pigments that contribute to the spectrum. However, the results in this report are consistent with an effective rank as determined by a variety of heuristic and statistical methods in the range of 2-3. These results are reviewed in consideration of how consistent the filter selections are from model to model for the data presented here. We discuss the common observation that rank is generally found to be relatively low even in many seemingly complex circumstances, so that it may be productive to assume a low rank from the beginning. If a low-rank hypothesis is valid, then relatively few samples are needed to explore an experimental space. Under very restricted circumstances for uniformly distributed samples, the minimum number for an initial analysis might be as low as 8-11 random samples for 1-3 factors.

  19. Day-roost tree selection by northern long-eared bats—What do non-roost tree comparisons and one year of data really tell us?

    USGS Publications Warehouse

    Silvis, Alexander; Ford, W. Mark; Britzke, Eric R.

    2015-01-01

    Bat day-roost selection often is described through comparisons of day-roosts with randomly selected, and assumed unused, trees. Relatively few studies, however, look at patterns of multi-year selection or compare day-roosts used across years. We explored day-roost selection using 2 years of roost selection data for female northern long-eared bats (Myotis septentrionalis) on the Fort Knox Military Reservation, Kentucky, USA. We compared characteristics of randomly selected non-roost trees and day-roosts using a multinomial logistic model and day-roost species selection using chi-squared tests. We found that factors differentiating day-roosts from non-roosts and day-roosts between years varied. Day-roosts differed from non-roosts in the first year of data in all measured factors, but only in size and decay stage in the second year. Between years, day-roosts differed in size and canopy position, but not decay stage. Day-roost species selection was non-random and did not differ between years. Although bats used multiple trees, our results suggest that there were additional unused trees that were suitable as roosts at any time. Day-roost selection pattern descriptions will be inadequate if based only on a single year of data, and inferences of roost selection based only on comparisons of roost to non-roosts should be limited.

  20. Day-roost tree selection by northern long-eared bats - What do non-roost tree comparisons and one year of data really tell us?

    USGS Publications Warehouse

    Silvis, Alexander; Ford, W. Mark; Britzke, Eric R.

    2015-01-01

    Bat day-roost selection often is described through comparisons of day-roosts with randomly selected, and assumed unused, trees. Relatively few studies, however, look at patterns of multi-year selection or compare day-roosts used across years. We explored day-roost selection using 2 years of roost selection data for female northern long-eared bats (Myotis septentrionalis) on the Fort Knox Military Reservation, Kentucky, USA. We compared characteristics of randomly selected non-roost trees and day-roosts using a multinomial logistic model and day-roost species selection using chi-squared tests. We found that factors differentiating day-roosts from non-roosts and day-roosts between years varied. Day-roosts differed from non-roosts in the first year of data in all measured factors, but only in size and decay stage in the second year. Between years, day-roosts differed in size and canopy position, but not decay stage. Day-roost species selection was non-random and did not differ between years. Although bats used multiple trees, our results suggest that there were additional unused trees that were suitable as roosts at any time. Day-roost selection pattern descriptions will be inadequate if based only on a single year of data, and inferences of roost selection based only on comparisons of roost to non-roosts should be limited.

  1. Raloxifene as an Adjunctive Treatment for Postmenopausal Women With Schizophrenia: A 24-Week Double-Blind, Randomized, Parallel, Placebo-Controlled Trial.

    PubMed

    Usall, Judith; Huerta-Ramos, Elena; Labad, Javier; Cobo, Jesús; Núñez, Christian; Creus, Marta; Parés, Gemma García; Cuadras, Daniel; Franco, José; Miquel, Eva; Reyes, Julio César; Roca, Mercedes

    2016-03-01

    The potential therapeutic utility of estrogens in schizophrenia is increasingly being recognized. Raloxifene, a selective estrogen receptor modulator, appears to act similarly to estrogens on dopamine and serotonin brain systems. One previous trial by our team found that raloxifene was useful to improve negative, positive, and general psychopathological symptoms, without having the negative side effects of estrogens. In this study, we assess the utility of raloxifene in treating negative and other psychotic symptoms in postmenopausal women with schizophrenia exhibiting prominent negative symptoms. This was a 24-week, randomized, parallel, double-blind, placebo-controlled study. Patients were recruited from the inpatient and outpatient departments of Parc Sanitari Sant Joan de Déu, Hospital Universitari Institut Pere Mata, and Corporació Sanitària Parc Taulí. Seventy postmenopausal women with schizophrenia (DSM-IV) were randomized to either adjunctive raloxifene (38 women) or adjunctive placebo (32 women). Psychopathological symptoms were assessed at baseline and at weeks 4, 12, and 24 with the Positive and Negative Syndrome Scale (PANSS) and the Scale for the Assessment of Negative Symptoms (SANS). The addition of raloxifene (60 mg/d) to regular antipsychotic treatment significantly reduced negative (P = .027), general (P = .003), and total symptomatology (P = .005) measured with the PANSS during the 24-week trial, as compared to women receiving placebo. Also Alogia SANSS subscale improved more in the raloxifene (P = .048) than the placebo group. In conclusion, raloxifene improved negative and general psychopathological symptoms, compared with antipsychotic medication alone, in postmenopausal women with schizophrenia. These data replicate our previous results with a larger sample and a longer follow-up. NCT01573637. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Efficacy and Safety of Vilazodone in Patients With Generalized Anxiety Disorder: A Randomized, Double-Blind, Placebo-Controlled, Flexible-Dose Trial.

    PubMed

    Durgam, Suresh; Gommoll, Carl; Forero, Giovanna; Nunez, Rene; Tang, Xiongwen; Mathews, Maju; Sheehan, David V

    2016-12-01

    To evaluate the efficacy, safety, and tolerability of vilazodone as an acute treatment for generalized anxiety disorder (GAD). Vilazodone is a selective serotonin reuptake inhibitor and 5-HT1A receptor partial agonist approved for the treatment of major depressive disorder in adults. This was a randomized, placebo-controlled, parallel-group, multicenter, flexible-dose study conducted from May 2013-March 2014. Adult patients (18-70 years, inclusive) who met DSM-IV-TR criteria for GAD were randomized (1:1) to placebo or vilazodone 20-40 mg/d for 8 weeks of double-blind treatment. Primary and secondary efficacy parameters were change from baseline to week 8 in the Hamilton Anxiety Rating Scale (HARS) total score and in the Sheehan Disability Scale (SDS) total score, respectively, analyzed using a mixed-effects model for repeated measures approach on a modified intent-to-treat population. Safety outcomes were summarized descriptively. Efficacy analyses were based on 400 patients (placebo = 200, vilazodone = 200); 76% completed the study (placebo = 81%, vilazodone = 71%). The least squares mean difference (95% CI) in total score change from baseline to week 8 was statistically significant for vilazodone versus placebo on the HARS (-2.20 [-3.72 to -0.68]; P = .0048) and on the SDS (-1.89 [-3.52 to -0.26]; P = .0236). Treatment-emergent adverse events reported in ≥ 5% of vilazodone patients and at least twice the rate of placebo were nausea, diarrhea, dizziness, fatigue, delayed ejaculation, and erectile dysfunction. Statistically significant differences in favor of vilazodone 20-40 mg/d versus placebo were seen on all measures of anxiety and functional impairment in patients with GAD. Vilazodone was generally well tolerated, and no new safety concerns were noted. ClinicalTrials.gov identifier: NCT01844115. © Copyright 2016 Physicians Postgraduate Press, Inc.

  3. Foundational errors in the Neutral and Nearly-Neutral theories of evolution in relation to the Synthetic Theory: is a new evolutionary paradigm necessary?

    PubMed

    Valenzuela, Carlos Y

    2013-01-01

    The Neutral Theory of Evolution (NTE) proposes mutation and random genetic drift as the most important evolutionary factors. The most conspicuous feature of evolution is the genomic stability during paleontological eras and lack of variation among taxa; 98% or more of nucleotide sites are monomorphic within a species. NTE explains this homology by random fixation of neutral bases and negative selection (purifying selection) that does not contribute either to evolution or polymorphisms. Purifying selection is insufficient to account for this evolutionary feature and the Nearly-Neutral Theory of Evolution (N-NTE) included negative selection with coefficients as low as mutation rate. These NTE and N-NTE propositions are thermodynamically (tendency to random distributions, second law), biotically (recurrent mutation), logically and mathematically (resilient equilibria instead of fixation by drift) untenable. Recurrent forward and backward mutation and random fluctuations of base frequencies alone in a site make life organization and fixations impossible. Drift is not a directional evolutionary factor, but a directional tendency of matter-energy processes (second law) which threatens the biotic organization. Drift cannot drive evolution. In a site, the mutation rates among bases and selection coefficients determine the resilient equilibrium frequency of bases that genetic drift cannot change. The expected neutral random interaction among nucleotides is zero; however, huge interactions and periodicities were found between bases of dinucleotides separated by 1, 2... and more than 1,000 sites. Every base is co-adapted with the whole genome. Neutralists found that neutral evolution is independent of population size (N); thus neutral evolution should be independent of drift, because drift effect is dependent upon N. Also, chromosome size and shape as well as protein size are far from random.

  4. Extended non-local games and monogamy-of-entanglement games.

    PubMed

    Johnston, Nathaniel; Mittal, Rajat; Russo, Vincent; Watrous, John

    2016-05-01

    We study a generalization of non-local games-which we call extended non-local games -in which the players, Alice and Bob, initially share a tripartite quantum state with the referee. In such games, the winning conditions for Alice and Bob may depend on the outcomes of measurements made by the referee, on its part of the shared quantum state, in addition to Alice and Bob's answers to randomly selected questions. Our study of this class of games was inspired by the monogamy-of-entanglement games introduced by Tomamichel, Fehr, Kaniewski and Wehner, which they also generalize. We prove that a natural extension of the Navascués-Pironio-Acín hierarchy of semidefinite programmes converges to the optimal commuting measurement value of extended non-local games, and we prove two extensions of results of Tomamichel et al.  concerning monogamy-of-entanglement games.

  5. Prescribing of psychotropic medication for nursing home residents with dementia: a general practitioner survey.

    PubMed

    Cousins, Justin M; Bereznicki, Luke Re; Cooling, Nick B; Peterson, Gregory M

    2017-01-01

    The aim of this study was to identify factors influencing the prescribing of psychotropic medication by general practitioners (GPs) to nursing home residents with dementia. GPs with experience in nursing homes were recruited through professional body newsletter advertising, while 1,000 randomly selected GPs from southeastern Australia were invited to participate, along with a targeted group of GPs in Tasmania. An anonymous survey was used to collect GPs' opinions. A lack of nursing staff and resources was cited as the major barrier to GPs recommending non-pharmacological techniques for behavioral and psychological symptoms of dementia (BPSD; cited by 55%; 78/141), and increasing staff levels at the nursing home ranked as the most important factor to reduce the usage of psychotropic agents (cited by 60%; 76/126). According to GPs, strategies to reduce the reliance on psychotropic medication by nursing home residents should be directed toward improved staffing and resources at the facilities.

  6. Extended non-local games and monogamy-of-entanglement games

    PubMed Central

    Johnston, Nathaniel; Mittal, Rajat; Watrous, John

    2016-01-01

    We study a generalization of non-local games—which we call extended non-local games—in which the players, Alice and Bob, initially share a tripartite quantum state with the referee. In such games, the winning conditions for Alice and Bob may depend on the outcomes of measurements made by the referee, on its part of the shared quantum state, in addition to Alice and Bob's answers to randomly selected questions. Our study of this class of games was inspired by the monogamy-of-entanglement games introduced by Tomamichel, Fehr, Kaniewski and Wehner, which they also generalize. We prove that a natural extension of the Navascués–Pironio–Acín hierarchy of semidefinite programmes converges to the optimal commuting measurement value of extended non-local games, and we prove two extensions of results of Tomamichel et al. concerning monogamy-of-entanglement games. PMID:27279771

  7. Social inheritance can explain the structure of animal social networks

    PubMed Central

    Ilany, Amiyaal; Akçay, Erol

    2016-01-01

    The social network structure of animal populations has major implications for survival, reproductive success, sexual selection and pathogen transmission of individuals. But as of yet, no general theory of social network structure exists that can explain the diversity of social networks observed in nature, and serve as a null model for detecting species and population-specific factors. Here we propose a simple and generally applicable model of social network structure. We consider the emergence of network structure as a result of social inheritance, in which newborns are likely to bond with maternal contacts, and via forming bonds randomly. We compare model output with data from several species, showing that it can generate networks with properties such as those observed in real social systems. Our model demonstrates that important observed properties of social networks, including heritability of network position or assortative associations, can be understood as consequences of social inheritance. PMID:27352101

  8. Moving with the times - familiarity versus formality in Australian general practice.

    PubMed

    Moore, Romayne; Yelland, Michael; Ng, Shu-Kay

    2011-12-01

    Forms of address between patients and general practitioners is an underexplored area which may influence productive dialogue within a consultation. This article aims to describe how Australian patients prefer to be addressed by their GP, how patients prefer to address their GP, and the factors influencing these preferences. Twenty consecutive patients of 13 randomly selected GPs (n=260) were surveyed on preferences for use of names in consultations and the factors influencing these preferences. Ninety percent of patients prefer to be addressed by their first name. Thirty-five percent of patients prefer to call the GP by first name, 27% by title and last name, 21% by title only, and 10% by title and first name. A range of influencing factors was identified. These findings allow GPs to feel confident in addressing their patients informally. They indicate the diversity of patient preferences for addressing their GP and the factors influencing these choices.

  9. Computerized stratified random site-selection approaches for design of a ground-water-quality sampling network

    USGS Publications Warehouse

    Scott, J.C.

    1990-01-01

    Computer software was written to randomly select sites for a ground-water-quality sampling network. The software uses digital cartographic techniques and subroutines from a proprietary geographic information system. The report presents the approaches, computer software, and sample applications. It is often desirable to collect ground-water-quality samples from various areas in a study region that have different values of a spatial characteristic, such as land-use or hydrogeologic setting. A stratified network can be used for testing hypotheses about relations between spatial characteristics and water quality, or for calculating statistical descriptions of water-quality data that account for variations that correspond to the spatial characteristic. In the software described, a study region is subdivided into areal subsets that have a common spatial characteristic to stratify the population into several categories from which sampling sites are selected. Different numbers of sites may be selected from each category of areal subsets. A population of potential sampling sites may be defined by either specifying a fixed population of existing sites, or by preparing an equally spaced population of potential sites. In either case, each site is identified with a single category, depending on the value of the spatial characteristic of the areal subset in which the site is located. Sites are selected from one category at a time. One of two approaches may be used to select sites. Sites may be selected randomly, or the areal subsets in the category can be grouped into cells and sites selected randomly from each cell.

  10. Selective enhancement of orientation tuning before saccades.

    PubMed

    Ohl, Sven; Kuper, Clara; Rolfs, Martin

    2017-11-01

    Saccadic eye movements cause a rapid sweep of the visual image across the retina and bring the saccade's target into high-acuity foveal vision. Even before saccade onset, visual processing is selectively prioritized at the saccade target. To determine how this presaccadic attention shift exerts its influence on visual selection, we compare the dynamics of perceptual tuning curves before movement onset at the saccade target and in the opposite hemifield. Participants monitored a 30-Hz sequence of randomly oriented gratings for a target orientation. Combining a reverse correlation technique previously used to study orientation tuning in neurons and general additive mixed modeling, we found that perceptual reports were tuned to the target orientation. The gain of orientation tuning increased markedly within the last 100 ms before saccade onset. In addition, we observed finer orientation tuning right before saccade onset. This increase in gain and tuning occurred at the saccade target location and was not observed at the incongruent location in the opposite hemifield. The present findings suggest, therefore, that presaccadic attention exerts its influence on vision in a spatially and feature-selective manner, enhancing performance and sharpening feature tuning at the future gaze location before the eyes start moving.

  11. Cooperation and charity in spatial public goods game under different strategy update rules

    NASA Astrophysics Data System (ADS)

    Li, Yixiao; Jin, Xiaogang; Su, Xianchuang; Kong, Fansheng; Peng, Chengbin

    2010-03-01

    Human cooperation can be influenced by other human behaviors and recent years have witnessed the flourishing of studying the coevolution of cooperation and punishment, yet the common behavior of charity is seldom considered in game-theoretical models. In this article, we investigate the coevolution of altruistic cooperation and egalitarian charity in spatial public goods game, by considering charity as the behavior of reducing inter-individual payoff differences. Our model is that, in each generation of the evolution, individuals play games first and accumulate payoff benefits, and then each egalitarian makes a charity donation by payoff transfer in its neighborhood. To study the individual-level evolutionary dynamics, we adopt different strategy update rules and investigate their effects on charity and cooperation. These rules can be classified into two global rules: random selection rule in which individuals randomly update strategies, and threshold selection rule where only those with payoffs below a threshold update strategies. Simulation results show that random selection enhances the cooperation level, while threshold selection lowers the threshold of the multiplication factor to maintain cooperation. When charity is considered, it is incapable in promoting cooperation under random selection, whereas it promotes cooperation under threshold selection. Interestingly, the evolution of charity strongly depends on the dispersion of payoff acquisitions of the population, which agrees with previous results. Our work may shed light on understanding human egalitarianism.

  12. Bayesian dynamic modeling of time series of dengue disease case counts

    PubMed Central

    López-Quílez, Antonio; Torres-Prieto, Alexander

    2017-01-01

    The aim of this study is to model the association between weekly time series of dengue case counts and meteorological variables, in a high-incidence city of Colombia, applying Bayesian hierarchical dynamic generalized linear models over the period January 2008 to August 2015. Additionally, we evaluate the model’s short-term performance for predicting dengue cases. The methodology shows dynamic Poisson log link models including constant or time-varying coefficients for the meteorological variables. Calendar effects were modeled using constant or first- or second-order random walk time-varying coefficients. The meteorological variables were modeled using constant coefficients and first-order random walk time-varying coefficients. We applied Markov Chain Monte Carlo simulations for parameter estimation, and deviance information criterion statistic (DIC) for model selection. We assessed the short-term predictive performance of the selected final model, at several time points within the study period using the mean absolute percentage error. The results showed the best model including first-order random walk time-varying coefficients for calendar trend and first-order random walk time-varying coefficients for the meteorological variables. Besides the computational challenges, interpreting the results implies a complete analysis of the time series of dengue with respect to the parameter estimates of the meteorological effects. We found small values of the mean absolute percentage errors at one or two weeks out-of-sample predictions for most prediction points, associated with low volatility periods in the dengue counts. We discuss the advantages and limitations of the dynamic Poisson models for studying the association between time series of dengue disease and meteorological variables. The key conclusion of the study is that dynamic Poisson models account for the dynamic nature of the variables involved in the modeling of time series of dengue disease, producing useful models for decision-making in public health. PMID:28671941

  13. Evaluation of Electromyographic Biofeedback for the Quadriceps Femoris: A Systematic Review

    PubMed Central

    Wasielewski, Noah J.; Parker, Tonya M.; Kotsko, Kevin M.

    2011-01-01

    Objective: To critically review evidence for the effectiveness of electromyographic biofeedback (EMGB) of the quadriceps femoris muscle in treating various knee conditions. Data Sources: Databases used to locate randomized controlled trials included PubMed (1980–2010), Cumulative Index of Nursing and Allied Health Literature (CINAHL, 1995–2007), Web of Science (1986–2010), SPORTDiscus (1990–2007), and Physiotherapy Evidence Database (PEDro). Key words were knee and biofeedback. Study Selection: The criteria for selection were clinical randomized controlled trials in which EMGB of the quadriceps femoris was used for various knee conditions of musculoskeletal origin. Trials were excluded because of research designs other than randomized controlled trials, articles published in a non-English language, inclusion of healthy research participants, inability to identify EMGB as the source of clinical improvement, and lack of pain, functional outcome, or quadriceps torque as outcome measures. Data Extraction: Twenty specific data points were abstracted from each clinical trial under the broad categories of attributes of the patient and injury, treatment variables for the EMGB group, treatment variables for the control group, and attributes of the research design. Data Synthesis: Eight trials yielded a total of 319 participants with patellofemoral pain syndrome (n = 86), anterior cruciate ligament reconstruction (n = 52), arthroscopic surgery (n = 91), or osteoarthritis (n = 90). The average methodologic score of the included studies was 4.6/10 based on PEDro criteria. Pooled analyses demonstrated heterogeneity of the included studies, rendering the interpretation of the pooled data inappropriate. The EMGB appeared to benefit short-term postsurgical pain or quadriceps strength in 3 of 4 postsurgical investigations but was ineffective for chronic knee conditions such as patellofemoral pain and osteoarthritis in all 4 studies. Because the findings are based on limited data, caution is warranted until more randomized controlled trials are conducted to support or refute the general trends observed in this report. PMID:22488142

  14. Types, frequencies, and burden of nonspecific adverse events of drugs: analysis of randomized placebo-controlled clinical trials.

    PubMed

    Mahr, Alfred; Golmard, Clara; Pham, Emilie; Iordache, Laura; Deville, Laure; Faure, Pierre

    2017-07-01

    Scarce studies analyzing adverse event (AE) data from randomized placebo-controlled clinical trials (RPCCTs) of selected illnesses suggested that a substantial proportion of collected AEs are unrelated to the drug taken. This study analyzed the nonspecific AEs occurring with active-drug exposure in RPCCTs for a large range of medical conditions. Randomized placebo-controlled clinical trials published in five prominent medical journals during 2006-2012 were searched. Only trials that evaluated orally or parenterally administered active drugs versus placebo in a head-to-head setting were selected. For AEs reported from ≥10 RPCCTs, Pearson's correlation coefficients (r) were calculated to determine the relationship between AE rates in placebo and active-drug recipients. Random-effects meta-analyses were used to compute proportions of nonspecific AEs, which were truncated at a maximum of 100%, in active-drug recipients. We included 231 trials addressing various medical domains or healthy participants. For the 88 analyzed AE variables, AE rates for placebo and active-drug recipients were in general strongly correlated (r > 0.50) or very strongly correlated (r > 0.80). The pooled proportions of nonspecific AEs for the active-drug recipients were 96.8% (95%CI: 95.5-98.1) for any AEs, 100% (97.9-100) for serious AEs, and 77.7% (72.7-83.2) for drug-related AEs. Results were similar for individual medical domains and healthy participants. The pooled proportion of nonspecificity of 82 system organ class and individual AE types ranged from 38% to 100%. The large proportion of nonspecific AEs reported in active-drug recipients of RPCCTs, including serious and drug-related AEs, highlights the limitations of clinical trial data to determine the tolerability of drugs. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Differential privacy-based evaporative cooling feature selection and classification with relief-F and random forests.

    PubMed

    Le, Trang T; Simmons, W Kyle; Misaki, Masaya; Bodurka, Jerzy; White, Bill C; Savitz, Jonathan; McKinney, Brett A

    2017-09-15

    Classification of individuals into disease or clinical categories from high-dimensional biological data with low prediction error is an important challenge of statistical learning in bioinformatics. Feature selection can improve classification accuracy but must be incorporated carefully into cross-validation to avoid overfitting. Recently, feature selection methods based on differential privacy, such as differentially private random forests and reusable holdout sets, have been proposed. However, for domains such as bioinformatics, where the number of features is much larger than the number of observations p≫n , these differential privacy methods are susceptible to overfitting. We introduce private Evaporative Cooling, a stochastic privacy-preserving machine learning algorithm that uses Relief-F for feature selection and random forest for privacy preserving classification that also prevents overfitting. We relate the privacy-preserving threshold mechanism to a thermodynamic Maxwell-Boltzmann distribution, where the temperature represents the privacy threshold. We use the thermal statistical physics concept of Evaporative Cooling of atomic gases to perform backward stepwise privacy-preserving feature selection. On simulated data with main effects and statistical interactions, we compare accuracies on holdout and validation sets for three privacy-preserving methods: the reusable holdout, reusable holdout with random forest, and private Evaporative Cooling, which uses Relief-F feature selection and random forest classification. In simulations where interactions exist between attributes, private Evaporative Cooling provides higher classification accuracy without overfitting based on an independent validation set. In simulations without interactions, thresholdout with random forest and private Evaporative Cooling give comparable accuracies. We also apply these privacy methods to human brain resting-state fMRI data from a study of major depressive disorder. Code available at http://insilico.utulsa.edu/software/privateEC . brett-mckinney@utulsa.edu. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  16. Microhabitat characteristics of Lapland Longspur, Calcarius lapponicus, nests at Cape Churchill, Manitoba

    USGS Publications Warehouse

    Boal, C.W.; Andersen, D.E.

    2005-01-01

    We examined microsite characteristics at 21 Lapland Longspur (Calcarius lapponicus) nests and land cover types in which they occurred in Wapusk National Park, Cape Churchill, Manitoba. Nests were located in four of six physiographic-vegetation land-cover types. Regardless of land-cover type, all but one nest was built on a pressure ridge or mound. Nests were built midway between the bottom and top of ridges or mounds with steeper slopes than was randomly available. Longspur nests had a distinctive southwest orientation (P < 0.001). Longspurs selected nest sites that consisted of comparatively greater amounts of shrub species and lesser amounts of moss than were randomly available. Nests were generally well concealed by vegetation (mean = 67.0%) and concealment was negatively associated with amount of graminoid species at the nest (P = 0.0005). Our nesting habitat data may facilitate a better understanding of breeding Lapland Longspur habitat requirements, and potential impacts of habitat degradation by increasing Snow Goose (Chen caerulescens) populations in the study area.

  17. Facebook and Twitter, communication and shelter, and the 2011 Tuscaloosa tornado.

    PubMed

    Stokes, Courtney; Senkbeil, Jason C

    2017-01-01

    This paper represents one of the first attempts to analyse the many ways in which Facebook and Twitter were used during a tornado disaster. Comparisons between five randomly selected campus samples and a city of Tuscaloosa, Alabama, sample revealed that campus samples used Facebook and Twitter significantly more both before and after the tornado, but Facebook usage was not significantly different after the event. Furthermore, differences in social media usage and other forms of communication before the tornado were found for age, education, and years lived in Tuscaloosa. Generally, age and education were inversely proportionate to social media usage. Influences on shelter-seeking actions varied between social media users and three random samples of non-social media users; however, it appears that social media respondents were likely to be using a smartphone simultaneously to access warning polygon information, to receive text message alerts, and to listen or respond to environmental cues. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

  18. Explanatory Versus Pragmatic Trials: An Essential Concept in Study Design and Interpretation.

    PubMed

    Merali, Zamir; Wilson, Jefferson R

    2017-11-01

    Randomized clinical trials often represent the highest level of clinical evidence available to evaluate the efficacy of an intervention in clinical medicine. Although the process of randomization serves to maximize internal validity, the external validity, or generalizability, of such studies depends on several factors determined at the design phase of the trial including eligibility criteria, study setting, and outcomes of interest. In general, explanatory trials are optimized to demonstrate the efficacy of an intervention in a highly selected patient group; however, findings from these studies may not be generalizable to the larger clinical problem. In contrast, pragmatic trials attempt to understand the real-world benefit of an intervention by incorporating design elements that allow for greater generalizability and clinical applicability of study results. In this article we describe the explanatory-pragmatic continuum for clinical trials in greater detail. Further, a well-accepted tool for grading trials on this continuum is described, and applied, to 2 recently published trials pertaining to the surgical management of lumbar degenerative spondylolisthesis.

  19. Physical states and finite-size effects in Kitaev's honeycomb model: Bond disorder, spin excitations, and NMR line shape

    NASA Astrophysics Data System (ADS)

    Zschocke, Fabian; Vojta, Matthias

    2015-07-01

    Kitaev's compass model on the honeycomb lattice realizes a spin liquid whose emergent excitations are dispersive Majorana fermions and static Z2 gauge fluxes. We discuss the proper selection of physical states for finite-size simulations in the Majorana representation, based on a recent paper by F. L. Pedrocchi, S. Chesi, and D. Loss [Phys. Rev. B 84, 165414 (2011), 10.1103/PhysRevB.84.165414]. Certain physical observables acquire large finite-size effects, in particular if the ground state is not fermion-free, which we prove to generally apply to the system in the gapless phase and with periodic boundary conditions. To illustrate our findings, we compute the static and dynamic spin susceptibilities for finite-size systems. Specifically, we consider random-bond disorder (which preserves the solubility of the model), calculate the distribution of local flux gaps, and extract the NMR line shape. We also predict a transition to a random-flux state with increasing disorder.

  20. Learning planar Ising models

    DOE PAGES

    Johnson, Jason K.; Oyen, Diane Adele; Chertkov, Michael; ...

    2016-12-01

    Inference and learning of graphical models are both well-studied problems in statistics and machine learning that have found many applications in science and engineering. However, exact inference is intractable in general graphical models, which suggests the problem of seeking the best approximation to a collection of random variables within some tractable family of graphical models. In this paper, we focus on the class of planar Ising models, for which exact inference is tractable using techniques of statistical physics. Based on these techniques and recent methods for planarity testing and planar embedding, we propose a greedy algorithm for learning the bestmore » planar Ising model to approximate an arbitrary collection of binary random variables (possibly from sample data). Given the set of all pairwise correlations among variables, we select a planar graph and optimal planar Ising model defined on this graph to best approximate that set of correlations. Finally, we demonstrate our method in simulations and for two applications: modeling senate voting records and identifying geo-chemical depth trends from Mars rover data.« less

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